The story

From Turning Stones to Launching Drones: Archaeological Surveys Take Flight


Drones are becoming ever more present tools for archaeologists looking to add to their survey and excavation toolkits. They’ve been used to get some great aerial views of archaeological sites and features and sometimes even to discover them! And researchers have now teamed up high-res drone pictures with some nifty machine learning to detect one of an archaeologist’s go to first finds – potsherds!

Fieldwalking and Aerial Photographs

Most archaeologists have had the pleasure of fieldwalking, aka ‘pedestrian surveying’ at some point in their career. This is a survey technique employed by a group of archaeologists, or archaeology students, who head out as a team to walk across a large area of open land they think may be of archaeological interest. Usually the land of choice for this survey method is a recently plowed farmer’s field , best if it’s rained not too long ago.

The team spreads out in a methodical grid-like manner, usually parallel lines of a set distance apart, to see if they can find any archaeological material that has been pushed to the surface – often that means pottery fragments ( potsherds). Flint tools and other artifacts are also found sometimes with this method.

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A team conducting a pedestrian archaeological survey aka “fieldwalking.” (Anna Karligioti)

It's notoriously long, hard, and sometimes tedious work, but fieldwalking has been a traditional practice since archaeology’s early days as a discipline.

Simplifying the Detection of Potsherds and More!

But new research published in the Journal of Archaeological Science suggests there may be a better way.

Dr. Hector A. Orengo of the Catalan Institute of Classical Archaeology and Dr. Arnau Garcia-Molsosa of the McDonald Institute for Archaeological Research at the University of Cambridge think they may have the answer to the fieldwalking headache, or at least the beginning of a solution. A University of Cambridge press release states that the researchers aim “to alleviate labor-intensive archaeological field surveying by combining machine learning and high-resolution drone imagery.”

Dr. Arnau Garcia-Molsosa and Dr. Orengo watching the drone. (Anna Karligioti)

What they have tested out is a new archaeological survey method – flying a pre-programmed drone over the area of interest and taking overlapping pictures. The images are then joined together to create what they call “a single very large high-resolution image.”

That high-res image is then analyzed by a machine learning (AI) algorithm that is meant to find all the specified archaeological material that is present in the image. The researchers tested out their method by setting the algorithm to identify potsherds through color and pixel texture, but say that it could “be trained to identify different types of material culture as well.” They’ve suggested stone tools and other lithics or metal could also be suitable materials of interest for this method.

You may be wondering why they started with potsherds – which are essentially busted up pieces of ceramic. Orengo provides this explanation:

“The distribution of potsherds is a good indication of the intensity of human occupation and the location of archaeological sites, but traditional survey methods can be quite costly and labor-intensive. Some of our projects in the Mediterranean involved the collection and recording of large quantities of pottery, but a single relatively small site could take our 6-people team three days to record! Automated survey was something we used to fantasize about while in the field.”

Garcia-Molsosa continues the idea:

“Under ideal circumstances this method is more accurate and faster than standard survey approaches. This is a complementary method to traditional pedestrian survey and has the potential to transform the way landscape survey is done. The automated recording of surface material culture has enormous possibilities to contribute to a wide array of projects working on academic research and heritage management. We hope that this technique can be employed, adapted and improved by other teams so we can understand better its potential application.”

This new method may be an interesting alternative to three days of walking across open fields, which is certainly time-consuming and often a costly matter (people are sometimes paid for the task and at least they need food and shelter if they’ll be trekking the fields for a few days).

‘The Lonesome Archaeologist’ Fieldwalking in 2014. (Paul Wood/ CC BY SA 2.0 )

Possibilities and Limitations

However, it is not perfect and the researchers also realize that there are some limitations to the method as it stands right now.

For example, they found the algorithm may provide false positives if the settings are more stringent and incorrectly suggest that modern brick fragments are pottery. Or, conversely, less strict settings could mean the algorithm misses some of the potsherds. Thankfully, this type of technical issue could probably be ironed out in the future. But until that happens, there is the question of how much time may really be saved – people still need to check the algorithms work and possibly go out and find and then pick up the potsherds by hand.

Upper image showing a drone-acquired image of the ground. Lower image showing the sherds detected by the machine learning algorithm. (Arnau Garcia-Molsosa and Hector A. Orengo)

A much larger limitation is that the method is currently still restricted to the same conditions as traditional fieldwalking – flat, plowed soils that are vegetation-free. However, the researchers say they “are now working on developing drone technologies that can better adapt to irregular terrain, avoid trees, and other barriers and extend the drone flight times that are currently available.” Now that could be a more useful surveying tool, but still means restrictions to land that is relatively plant-free.

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Orengo and Garcia-Molsosa state they are also working on creating “new artificial intelligence-based methods to improve the algorithm detection ratio and extend its identification abilities to other types of material culture, such as lithics and metal.” This would be a nice addition to the current focus on potsherds.

Another cause of concern is how viable this method will be in the future. Drones are still relatively new technology, but legislation is changing and restrictions on drone usage are emerging. If too much red tape is added, it may be easier for archaeologists to just stick with the old ways than wait for permission to use their aerial tools.

Drones may not be permitted in some areas of archaeological interest. ( CC0)

But in the end the researchers still see their drone-machine learning set up as a complementary method to the good old-fashioned ways of or archaeological forebears – fieldwalking. It seems that even while archaeology is taking technological steps into the future with drones and scans, there is still one foot in the past and keeping some (useful) traditions alive.


Drones Seek Out Lost Shipwrecks Below Lake Huron

Lake Huron’s Thunder Bay is known as shipwreck alley for a reason. Nearly two hundred ships met their end here, and at least half were never found.

If this sounds like a maritime archaeologist’s dream — it is. But there’s just one problem. It’s difficult, and in some cases impossible, to use traditional underwater survey tools in much of the bay’s shallow, rocky shoreline.

Researchers are now turning to drones and mapping software to locate wrecks in the shallow waters of inaccessible coastlines. Drone-focused nonprofit Oceans Unmanned recently set out to help marine archaeologists leverage drone data to find the lost shipwrecks of Thunder Bay.


Ask Andrea — How To Launch & Land a Mapping Drone

In Waypoint’s regular segment, Ask Andrea, senseFly’s Product and Training Manager, Andrea Blindenbacher, answers questions on launching and landing a mapping drone, such as why it’s important to take off and land against the wind and what do if something unexpected happens during your landing approach.

Question: How do I successfully launch a mapping drone?

I get this question a lot, and with fixed-wing drones, such as the eBee X fixed-wing drone, it’s important to remember that takeoffs are linear, just like an airplane.

Remember that you always want to try and take off against the wind, which allows the aircraft to climb. With tailwind, the plane, in our case the mapping drone, is pushed toward the ground and has a harder time gaining altitude.

Another thing to remember is that the angle of the aircraft the moment it takes off—the angle of attack—is important. With the eBee X, that angle should be 45 degrees. At this angle, air flows around the wings and the aircraft is basically sucked up into the air. Here is a link to a diagram that provides a good example of this.

The transition altitude is another factor that contributes to a successful launch. This is the altitude at which an eBee stops its linear climb and begins to make its way to the starting waypoint, which is defined in senseFly’s eMotion drone flight software.

By default, this is set at 20 m (66 ft) Above Take Off (ATO). It can be useful to increase this transition altitude to 30 m or even 40 m (98 and 131 ft, respectively) to make sure that one clears all potential obstacles once the eBee gets to its starting waypoint, which it can do by turning either left or right. These could be anything from trees and buildings to powerlines and other man-made obstacles.

One helpful tip I like to give people is that it’s also possible to force a directional launch, meaning that the eBee follows one exact line, without adapting to slight changes in wind direction, until it reaches the transition altitude desired.

Question: What makes a successful landing?

Of course, we always want the mapping drone to come back down safely, so an important concept to understand when it comes to landing is that the home waypoint and landing position are linked.

The home waypoint is always located in the air and is set to 75 m (246 ft) ATO in eMotion by default, while the landing position is on the ground at 0 m ATO. Therefore, moving the home waypoint changes the landing position.

Once the drone comes back down for landing it will depart doing a downwind leg, turn into the wind and start its descent at the landing position. Remember: this approach must face the wind (same with launching) because the wind helps it to slow down while maintaining its attitude and prevents it from rapidly descending.

This descent happens at a specific angle and is defined by the mapping drone’s configuration. Therefore, the start of the approach zone must be at a certain distance (around 250 m or 820 ft) from the landing position. This is set by default in senseFly’s eMotion flight-planning software and cannot be changed by the user. It’s also best to choose an obstacle-free trajectory for the last 60m (197 ft) of the approach, keeping the wind direction in mind.

Finally, the width of the approach zone can be defined more loosely. A large approach zone allows the eBee mapping drone to choose its trajectory (it will choose the most “wind-facing” trajectory). Conversely, a very narrow approach zone will force the drone to follow a certain trajectory. If not aligned correctly with the wind direction, this can lead to harder landings or side drift due to crosswind.

It’s also helpful to remember that if at any time it looks like your landing is off a little or isn’t going the way you want it to, or anything unexpected happens within the landing area, the procedure can be aborted using the control button “ABORT” or by simply hitting the spacebar on your keyboard.

Do you have drone-related questions for Andrea? Ask in the comments section below and your question might get featured in a future post.


Peruvian Archaeologists Use Drones To Spy On Ancient Sites

Remote-controlled aircraft were developed for military purposes and are a controversial tool in U.S. anti-terrorism campaigns, but the technology's falling price means it is increasingly used for civilian and commercial projects around the world.

Small drones have been helping a growing number of researchers produce three-dimensional models of Peruvian sites instead of the usual flat maps - and in days and weeks instead of months and years.

Speed is an important ally to archaeologists here. Peru's economy has grown at an average annual clip of 6.5 percent over the past decade, and development pressures have surpassed looting as the main threat to the country's cultural treasures, according to the government.

Researchers are still picking up the pieces after a pyramid near Lima, believed to have been built some 5,000 years ago by a fire-revering coastal society, was razed in July by construction firms. That same month, residents of a town near the pre-Incan ruins of Yanamarca reported that informal miners were damaging the three-story stone structures as they dug for quartz.

And squatters and farmers repeatedly try to seize land near important sites like Chan Chan on the northern coast, considered the biggest adobe city in the world.

Archaeologists say drones can help set boundaries to protect sites, watch over them and monitor threats, and create a digital repository of ruins that can help build awareness and aid in the reconstruction of any damage done.

"We see them as a vital tool for conservation," said Ana Maria Hoyle, an archaeologist with the Culture Ministry.

Hoyle said the government plans to buy several drones to use at different sites, and that the technology will help the ministry comply with a new, business-friendly law that has tightened the deadline for determining whether land slated for development might contain cultural artifacts.

Commercial drones made by the Swiss company senseFly and the U.S. firms Aurora Flight Sciences and Helicopter World have all flown Peruvian skies.

Drones are already saving archaeologists time in mapping sites - a crucial but often slow first step before major excavation work can begin. Mapping typically involves tedious ground-level observations with theodolites or pen and paper.

"With this technology, I was able to do in a few days what had taken me years to do," said Luis Jaime Castillo, a Peruvian archaeologist with Lima's Catholic University and an incoming deputy culture minister who plans to use drones to help safeguard Peru's archaeological heritage.

Castillo started using a drone two years ago to explore the San Jose de Moro site, an ancient burial ground encompassing 150 hectares (0.58 square miles) in northwestern Peru, where the discovery of several tombs of priestesses suggests women ruled the coastal Moche civilization.

"We have always wanted to have a bird's-eye view of where we are working," said Castillo.

In the past, researchers have rented crop dusters and strapped cameras to kites and helium-filled balloons, but those methods can be expensive and clumsy. Now they can build drones small enough to hold with two hands for as little as $1,000.

"It's like having a scalpel instead of a club, you can control it to a very fine degree," said Jeffrey Quilter, an archaeologist with Harvard University who has worked at San Jose de Moro and other sites in Peru. "You can go up three meters and photograph a room, 300 meters and photograph a site, or you can go up 3,000 meters and photograph the entire valley."

Drones , also known as unmanned aerial vehicles or UAVs, have flown over at least six different archaeological sites in Peru in the past year, including the colonial Andean town Machu Llacta some 4,000 meters (13,123 feet) above sea level.

Peru is well known for its stunning 15th century Machu Picchu ruins, likely a getaway for Incan royalty that the Spanish were unaware of during their conquest, and the Nazca Lines in southern Peru, which are best seen from above and were mysteriously etched into the desert more than 1,500 years ago.

But archaeologists are just as excited about other chapters of Peru's pre-Hispanic past, like coastal societies that used irrigation in arid valleys, the Wari empire that conquered the Andes long before the Incas, and ancient farmers who appear to have been domesticating crops as early as 10,000 years ago.

With an archaeology budget of around $5 million, the Culture Ministry often struggles to protect Peru's more than 13,000 sites. Only around 2,500 of them have been properly marked off, according to the ministry.

"And when a site is not properly demarcated, it is illegally occupied, destroyed, wiped from the map," said Blanca Alva, an official with the ministry charged with oversight.

Steve Wernke, an archaeologist with Vanderbilt University exploring the shift from Incan to Spanish rule in the Andes, started looking into drones more than two years ago.

He tried out a drone package from a U.S. company that cost around $40,000. But after the small plane had problems flying in the thin air of the Andes, Wernke and his colleague, engineer Julie Adams, teamed up and built two drones for less than $2,000.

The drones continue to have altitude problems in the Andes, and Wernke and Adams now plan to make a drone blimp.

"There is an enormous democratization of the technology happening now," Wernke said, adding that do-it-yourself websites like DIYdrones.com have helped enthusiasts share information.

"The software that these things are run on is all open-source. None of it is locked behind company patents," he said.

There are some drawbacks to using drones in archaeology. Batteries are big and short-lived, it can take time to learn to work with the sophisticated software and most drones struggle to fly in higher altitudes.

In the United States, broader use of drones has raised privacy and safety concerns that have slowed regulatory approvals. Several states have drafted legislation to restrict their use, and one town has even considered offering rewards to anyone who shoots a drone down.

But in Peru, archaeologists say it is only a matter of time before drones replace decades-old tools still used in their field, and that the technology can and should be used for less destructive uses.

"So much of the technology we use every day comes from warfare," said Hoyle. "It is natural this is happening."

Some of the first aerial images taken of Peru's archaeological sites also have their roots in combat.

The Shippee-Johnson expedition in 1931 was one of several geographic surveys led by U.S. military pilots that emerged from the boom in aerial photography during World War I. It produced reams of images still used by archaeologists today.

After seeing one of those pictures at a museum in New York some 10 years ago, Wernke decided he would study a town designed to impose Spanish culture on the indigenous population in the 1570s. He describes it as "one of the largest forced resettlement programs in history."

"I went up the following year to see it and found the site, and I said, 'OK, that's going to be a great project once I can afford to map it," said Wernke. He said drones have mapped nearly half of his work site. "So it all started with aerial images in the '30s, and now we want to go further with UAVs."


Contents

  • The first atomic bomb (code named Trinity) was test detonated at Trinity Site near the northern boundary of the range on 16 July 1945, seven days after the White Sands Proving Ground was established. [7]
  • After the conclusion of World War II, 100 long-range German V-2 rockets that were captured by U.S. military troops were brought to WSMR. Of these, 67 were test-fired between 1946 and 1951 from the White Sands V-2 Launching Site. (This was followed by the testing of American rockets, which continues to this day, along with testing other technologies.) 's Space Shuttle Columbia landed on the Northrup Strip at WSMR on 30 March 1982 as the conclusion to mission STS-3. [8] This was the only time that NASA used WSMR as a landing site for the space shuttle.

Incidents Edit

  • Circa 30 May 1947, a German V-2 sounding rocket fired from White Sands Proving Ground veered off course, crashed and exploded on top of a rocky knoll 3.5 miles south of the Juarez, Mexico business district. [9]
  • On 11 July 1970, the United States Air Force launched an Athena sounding rocket, equipped with re-entry vehicle V-123-D, from the Green River Launch Complex in Utah. While its intended target was inside of WSMR, the rocket instead flew south and impacted 180–200 miles south of the Mexican border in the Mapimi Desert in the northeastern corner of the Mexican state of Durango. [10]

The largest military installation in the United States, WSMR encompasses almost 3,200 sq mi (8,300 km 2 ) that includes parts of five counties in southern New Mexico:

Nearby military bases Edit

  • WSMR borders the 600,000-acre (2,400 km 2 ) McGregor Range Complex at Fort Bliss to the south (southeast Tularosa Basin and on Otero Mesa[11] ) making them contiguous areas for military testing. [12] borders WSMR to the east.

Nearby cities Edit

National park and wildlife refuge Edit

The following federally-protected natural areas are contained within the borders of WSMR:

Major highways Edit

    traverses the southern part of the range in a west-northeast direction and is subject to periodic road closures during test firings at the range. enters the range from the south from Chaparral, New Mexico and terminates at U.S. Highway 70.

Nearby airports Edit

    – No current regularly scheduled commercial passenger flights since 25 July 2005, when Westward Airways ceased operations. General aviation, New Mexico Army National Guard (4 UH-72 Lakota Helicopters), private charters and CAP use the airport, among others. – Nearest airport with regularly scheduled commercial flights.

Designated historic sites on WSMR land include:

    : Selected in November 1944 for the Trinity nuclear test conducted on 16 July 1945 [13] (National Historic Landmark district on 21 December 1965, [14][15]NRHP on 15 October 1966). [16] : A V-2 static test firing was 15 March 1946, and the first US V-2 launch was 16 April 1946 (landmark designation 3 October 1985). [17][18]

The White Sands Test Center headquartered at the WSMR "Post Area" has branches for Manned Tactical Systems & Electromagnetic Radiation and conducts missile testing and range recovery operations. [19] Other operations on WSMR land include:


Monitoring animal populations

It is hardly surprising that biologists were the first to see the value of drones. Equipped with a high-definition camera, a drone is the ideal tool to map biodiversity, and in particular to carry out surveys of animal populations, in areas that are difficult to access. "For the moment, we're operating at an altitude of a few tens of meters," says David Grémillet, a biologist at the CEFE.2 Researchers are very tempted to get closer, as amateur wildlife videos shot using drones are invading the Net. "Using drones is fine, but it is essential to do so without disturbing the animals," points out Grémillet, whose team recently carried out a real-life test on a population of flamingos in France's Camargue region. "We wanted to find out how close we could get without causing the birds to move their heads or run along the ground. So we varied the angle and speed of approach, the color of the drone, and the final distance between the drone and the flamingos."


How to Take Your Event to New Heights with Drones

Just because everyone is launching drones in the expo center, doesn’t mean you need to start mapping routes around the chandelier for your next ballroom takeover. Strategic use of remote controlled devices can be a great way to capture the experience from a new angle, stream to remote audiences and keep an eye on things, but taking precaution is recommended.

Create the Ultimate Immersive Experience

Unmanned aerial vehicles (UAVs) have come a long way since they were tested on reconnaissance missions along the Ho Chi Minh Trail during the Vietnam War. Improved endurance and higher clearance has made them popular for lots of non-military purposes, including law enforcement, search and rescue and geographical mapping. Drones have become popular event accessories because they enable live-streaming for remote access. Creating an immersive experience allows for up-to-the-minute updates and is a surefire way to guarantee that you are on the cutting edge of technology.

Add Virtual Reality to Your Drone Technology

DJI Goggles connect wirelessly to the Mavic Pro drone, so that users have aerial views of events without ever having to leave the ground. The goggles allow HD livestreaming over short distances, and the head-tracking mode allows users to control camera movements by simply turning their heads. Incorporating the latest technology in this way will lend your brand originality and is sure to be a talking point long after the show is over.

Smart Tip: Put your company’s name on the drone to maximize the opportunity for brand exposure.

Make Security a Priority

Drones not only assist in documenting your event in real-time and making events memorable, they can also act as a security feature. Drones fitted with cameras offer the possibility of continuous aerial monitoring, allowing for the detection of suspect behavior or security violations. This way, if an incident occurs, security personnel can react efficiently, leaving you to focus on the meeting.

Considerations

With any new venture comes responsibility, and you’ll want the drone to be the talking point of your event for all the right reasons. Since they are considered aircraft, drones are regulated by the FAA, and any violations of these regulations are subject to penalties and/or criminal charges. How can you best equip yourself before sending in the drones?

Pre-flight

  • Be sure that your battery is fully charged
  • Check the propellers for cracks
  • If your drone runs alongside an app such as DJI Go, make sure that there are no firmware updates that need to run
  • Calibrate the drone’s compass, which can be done through the app interface

In-flight

Though indoor drones are covered by fewer regulations, if your event is outdoors, be sure to:


Regional setting

The Dampier Archipelago (Murujuga) is located in the semi-arid Pilbara region of northwest Australia (Fig 1), and experiences low and variable rainfall averaging less than 350 mm per annum. The archipelago is also situated in one of the most cyclone-prone regions in the world. Thirty-six tropical cyclones crossed the Pilbara coast between 1980 and 2007, and a major cyclone, Cyclone Veronica, passed over the area in March 2019 towards the end of the project’s field campaigns. The potential for cyclone activity to cause disturbance, displacement or destruction of archaeological material in coastal areas is a major factor that needs to be considered when assessing the integrity or otherwise of coastal archaeological sites and their post-depositional history [40]. The timing of Cyclone Veronica provided an unusual opportunity to compare the distribution and condition of archaeological materials before and after the event and to assess the impact of cyclone activity.

1) Cape Bruguieres Island (2) North Gidley Island (3) Flying Foam Passage (4) Dolphin Island (5) Angel Island (6) Legendre Island (7) Malus Island (8) Goodwyn Island (9) Enderby Island.

The north–south oriented Mermaid Sound separates the archipelago into two island groups. The eastern islands are an extension of the Burrup Peninsula and are formed from 2.7 billion-year-old rhyodacite (also known as granophyre) and gabbros. The western islands are formed from similar-age basalts and andesites [41]. Pleistocene-age aeolianites and cemented beach sediments of mid-to-late Holocene age (calcarenite) are also present around the islands’ coastal fringes and embayments. The former are cemented sand dunes accumulated during earlier periods of high sea level (MIS 5 or earlier) and are characterised by their reddish colour the Holocene calcarenites are cemented beach deposits including beachrock formed in association with the establishment of modern sea level and are creamy-white in colour.

The igneous geology has eroded into a rough and complex sheet-fractured nubbin terrain with ridgelines of massive boulders (often unvegetated), and valleys which form a rectangular drainage pattern. Freshwater is seasonally available in narrow ephemeral creeks filled by rainfall and in springs [41]. This geology provides abundant and ubiquitous material for manufacture of stone tools and artificial stone structures [42]. It also affords numerous boulders and fractured slabs with surfaces suitable for rock engravings, of which there are estimated to be c. 1 million for the Murujuga rock art province [43]. The slow weathering rates of this geology [44] have created the ideal conditions for the preservation of a human artistic record that could have survived as far back as the 50,000 cal BP that humans are known to have occupied this part of the north-west coast [7].

At the Last Glacial Maximum, the coastline was located 160 km further offshore [45], exposing a gently seaward-sloping coastal plain composed of marine carbonate and siliciclastic sediments, dotted with springs and stream channels, and with fringing mangroves and swamps along palaeocoastlines. Palaeochannels, stranded palaeoshorelines, carbonate reefs, and isolated knolls would have created local relief on the exposed coastal plain. Sea-level rise after the LGM (c. 18,000 cal BP) progressively drowned this landscape, reaching a mid-Holocene highstand of approximately +2 m (MSL) (2 m above modern Mean Sea Level) by 7000 cal BP and subsequently regressing from approximately 5000 cal BP to present sea level (Fig 2 [46]).

(left) a composite coral growth history from Western Australia, figure modified from [47], blue line (in left insert) represents the minimum age of inundation. (right) Red Sea deep sea oxygen isotope sea level record (blue line) with lower and upper 95% confidence limits (dotted blue line) data from [48].

The characteristic archaeology of the region is dominated by open-air sites: especially engraved rock art panels as noted above, but also includes: stone tool assemblages quarries circular or curvilinear stone structures interpreted as hut foundations or terraces to enhance trapping of sediment standing stones of probable ceremonial significance and shell middens, sometimes forming shell mounds up to 5 m thick [42, 49]. Age determinations fall predominantly within the Holocene (the past ten thousand years), but the sequence of rock art styles includes extinct animals, demonstrating a longer history of occupation extending back into the Pleistocene [42, 43, 45, 49, 50]. Rockshelters with stratified and dateable deposits are rare in this type of geology, but one granite overhang on the Burrup Peninsula contains deposits with evidence of occupation extending from 21,000 to 7000 cal BP [51] while excavations of limestone caves on the more distant Barrow Island have yielded a sequence between 50,000 and 8000 cal BP, confirming the Pleistocene time depth of human activity in the region [7]. The lithic raw materials and food remains found within these sites demonstrate their use as bases for wide-ranging movements into the hinterland and out onto the coastal plain exposed at lower sea level. As sea level rose and the shoreline moved progressively closer, stratified food remains and changing rates of artefact discard show changing patterns of site use and movement across the landscape, increased representation of marine foods, and ultimately abandonment and a reconfiguration of land-use patterns adjusted to the modern coastline [51]. Similarly, rock art motifs show an increase in marine animals with progressive sea-level rise.

Research strategy and methods

The team deployed a suite of remote-sensing methods to map and interpret the landscape through an iterative process conducted over a series of six field campaigns between 2017 and 2019 [28, 52]. These were designed to identify submarine features of interest and specific targets for closer inspection, to locate submerged archaeological sites for diver inspection, and to recover and analyse geological, geochronological and archaeological samples.

Each of the remote sensing methods and equipment described below has its strengths and limitations, and methods were chosen because of their complementarity and their suitability in combination to provide information at a variety of geographical scales and with varying degrees of resolution and precision. Techniques applied ranged from mapping of topography and bathymetry at a sub-regional scale to high-precision recording of the positions of individual stone artefacts on the seabed. By combining different methods in this way over a series of field campaigns, comparing their results and adjusting subsequent surveys accordingly, the team established a picture of the submerged landscape and identified prospective targets for closer investigation.

This iterative process was designed to take into account five variables: (1) locations likely to have been attractive to the original inhabitants because of proximity to resources such as water supplies and raw materials for stone-artefact manufacture (2) locations likely to have preserved archaeological materials because of topographic features such as peninsulas and semi-enclosed basins providing protection from destructive wave action and ocean currents, or rock overhangs and cliff lines affording concentration and preservation of accumulated sediments (3) locations where material was not only likely to have survived sea-level rise but would be sufficiently exposed to be discovered (4) local knowledge of community members including Traditional Owners and fishermen (5) accessibility for diver investigation.

Because of limitations on the water depth in which some of these techniques can be applied and their logistical requirements, and taking as a starting point the principle of working from the known (the present-day land surface and its archaeology) to the unknown (the submerged landscape), focus is placed on shallow-water conditions (down to depths of c. 20 m) as a first step into the unknown, and travel distances offshore within relatively easy reach of small support vessels and modern harbour facilities. Investigations at greater depth and further offshore and the search for evidence buried beneath marine sediments pose different challenges and require different technologies and equipment, larger support vessels and different principles of research design and method, a point that is considered further in the final discussion. Fuller details and the results obtained by remotely sensed mapping are presented elsewhere [28] or are in preparation.

All necessary permits were obtained for the described study, which complied with all relevant regulations. The project was conducted under Flinders University ethics approval SBREC7669 and with the approval of the Murujuga Aboriginal Corporation by Circle of Elders vote (19th January 2017). Mapping and sampling was conducted under a Western Australia Department of Parks and Wildlife permit under Regulation 4(1) (5th May 2019). Permission to undertake further analysis of the artefacts was granted by the Murujuga Aboriginal Corporation. Sampled cultural material was repatriated and remains in the possession of the Traditional Owners (see supporting information). The specific techniques and methods which resulted in the successful location of two submerged sites are described in further detail below.

Airborne LiDAR survey

For onshore and offshore aerial survey and mapping of terrestrial and submarine surfaces at a variety of scales, the team deployed a Diamond Aircraft HK36TTC-ECO Dimona motorglider with two LiDAR systems mounted in under-wing pods: a Riegl Q680i-S (topographic) and a Riegl VQ-820-G (topo-bathymetric), each combined with a tactical grade IMU/GPS system (Novatel SPAN ISA/LCI). A Canon 5D Mk4 was fitted with an EF 24 mm (f/1.4LII USM) lens and co-mounted with the Q680i-S. Point cloud density ranged between 10 and 20 points/m 2 , and data was processed and converted to a Digital Elevation Model (DEM) using the Global Mapper LiDAR module. Airborne mapping offers enormous flexibility in areal coverage and is the only method that can produce a seamless continuum of images and measurements across the interfaces between land, the intertidal zone and the adjacent seabed, including measurements of relatively high precision in both the vertical and the horizontal dimension. Its limitation is that it is confined to shallow water, in the study area region down to water depths of c. 12 m.

Marine survey

For more detailed examination of sea-bed surfaces and topographic irregularities and exploration of deeper areas of the seabed, a total of 347 linear km covering approximately 150km 2 were surveyed with an EdgeTech 4125 sidescan sonar system, operated from an 8.5 m support vessel. Survey areas were gridded using Hypack navigation software, with line spacing ranging from 200 m as a minimum to 30 m for higher-resolution coverage of areas of particular interest. Parallel transects were run over selected areas to ensure a systematic and comprehensive coverage of the seabed. Sidescan instrument real-time locations and sonar mosaics were completed in the SonarWiz processing software. In certain areas where more systematic measurements of seabed bathymetry were required, sidescan imagery was supplemented with multibeam bathymetric data acquired from EGS Survey and Australian Marine Services.

Diver surveys

Once target features of potential significance were identified, the team deployed archaeologically trained divers for closer inspection and sample recovery, using standard safety protocols for scientific diving. Generally, teams of two or four underwater archaeologists worked together on a pre-determined dive plan during any given dive. The navigation system of the dive support vessel was used to position pre-defined survey lines laid out in a GIS with references to aerial and LiDAR basemaps. Survey lines were set using a 100 m leaded line attached to a shot weight with marker buoys on either end. Dive teams carried a marker float with a Garmin eTrex GPS to log location, documented any visible archaeological material and made geological descriptions that included changes in seabed composition (Fig 3). Cameras and GPS were calibrated to enable georeferencing of all photographs. The team explored a number of potential targets in this way before selecting for more detailed investigation the two sites examined here.

(above) Westward facing aerial view of Cape Bruguieres Channel at high tide (Photo: J. Leach) (below) divers record artefacts in the channel (Photos: S. Wright, J. Benjamin, and M. Fowler).

Artefact analysis

Underwater artefacts were examined in situ and recorded with as much information as possible without removal. However, many analyses could not be carried out except in laboratory conditions and a sample of artefacts was removed for that purpose. Each artefact was given a unique accession number, measured, and photographed. The morphological features recorded were raw material type, colour and quality maximum length, breadth and thickness (in cm) weight (g) artefact type including a range of features specific to flakes and cores and presence and nature of retouch. Since the amount of marine growth present often meant that characteristic features were obscured, comments on each artefact included an assessment of whether it was a definite, probable or possible artefact (see S1 Table). The nature of the marine growth was also described. This included corals, sponges, bryozoans, tubeworms, foraminifera and coralline algae, the presence and relative composition of which changed relative to depth of submersion. Some of these marine growths were sampled for potential age determination (see below). A selection of these artefacts was hand drawn and captured in 3D using a Sony RX100iii and Agisoft Metashape (v 1.6). The team also applied neutron tomography to selected lithics using the synchrotron at the ANSTO DINGO beam facility in Sydney [53] in order to remove surface marine concretions digitally to reveal the shape of the artefact more clearly.

Geological sampling

For the analysis of artefact and local igneous rock geochemistry to identify the sources of raw materials used in artefact manufacture, the team used a handheld Portable X-Ray fluorescence (pXRF) device–a Niton XL3t GOLDD+ TestAll Geo, standards in SOIL 99.995 SiO2 (pure silica standard) using the NIST 2709a soil and sediment standard. This facilitated measurement in the field as well as in the laboratory. In the laboratory, a 5% v/v solution of HCl was used to remove carbonate followed by cleaning with DI water to pXRF selected artefacts from the Cape Bruguieres Channel. For dating and geological analysis of the various aeolianite and calcarenite substrates on which artefacts were located, samples were extracted by hand using a hammer and chisel, or a drill core.

Radiocarbon ( 14 C) dating of marine materials

Accelerator Mass Spectrometry (AMS) radiocarbon age determinations on marine shell and coral embedded in aeolianite and calcarenite were undertaken at the University of Waikato Radiocarbon Dating Laboratory and the Scottish Universities Environmental Research Centre (SUERC) Radiocarbon Dating Laboratory. Surfaces of samples were cleaned, washed in an ultrasonic bath, acid etched in HCl, rinsed and dried. Shells were tested for recrystallization by Feigl staining [54]. CO2 was collected and reduced to graphite. Pressed graphite was either analysed at the Keck Radiocarbon Dating Laboratory, University of California [55] or at SUERC [56]. Radiocarbon ages were calibrated using OxCal (version 4.3) [57]. Pre-modern radiocarbon ages were calibrated using the Marine13 dataset [58], with a ΔR of 109±25 [7]. Modern radiocarbon ages (F 14 C%≥100) were approximately calibrated with reference to post-AD 1950 F 14 C regional marine concentrations [59].

Aerial drone survey

Where aerial photography of higher resolution was required, low altitude drones were deployed for mapping of surfaces and features on land and across the intertidal zone when exposed at low tide. This proved especially valuable in mapping the position and distribution of artefacts and even smaller items in order to assess the degree of disturbance caused by Cyclone Veronica. A DJI Phantom 4 Pro and Mavic 2 were flown with automated flight planning software (Drone Deploy) and employed two survey strategies: single-line transects flown between 75–20 ft above the ground level (AGL) and large-area surveys flown at 82 ft AGL with a frontlap of 75% and a sidelap of 70% to produce a ground sample distance of 1 cm. Images were imported into Agisoft Metashape (v 1.5.4) to create point cloud data using settings for Highest Accuracy, Ultra High Quality and Aggressive Filtering. Resulting dense clouds were filtered to achieve 1 cm point spacing, resulting in data sets containing more than 500 million points. These, in turn, were cropped into five 25 x 25 m sample areas and imported into CloudCompare (v2.11) to facilitate comparison between the two datasets. This approach drastically reduced vertical distortion between the two datasets and allowed for effective quantitative comparison between drone runs conducted over the same surface before and after Cyclone Veronica.


The use of UAV for rock mass classification and structural analysis

Rock mass characterization has always been a challenging aspect to analyze the different modes of failure of both natural and human-made slopes. Rock collapses can be due to a series of predisposing and triggering factors, mostly depending on localized geological conditions. According to Zajc et al. (2014), hazardous situations may occur when unfavorable sedimentological characteristics and geological discontinuities (e.g., fractures, faults) of rock masses are made even more critical due to the realization of engineered slope-cuts (e.g., stone extraction, civil infrastructures). At the same time, Zheng et al. (2015) underlain the crucial role played by morphological features, like sharp cuts and steep slopes, for the triggering of rockfalls in mining areas. As demonstrated in the literature, the understanding of geometric relationships between geological discontinuities and slope morphology is essential to evaluate the potential occurrence of rock failures, since the orientation of fracture sets may influence both size and failure mechanisms of rock blocks prone to collapse (Stead and Wolter 2015).

Generally, fracture characterization is carried out in the field by traditional engineering-geological surveys (Priest 1993). Data are traditionally obtained from scan-line mapping using the following technical equipment: (i) geologist’s compass with clinometer (ii) closed case steel tape 50 m (iii) Schmidt hammer the output data consists of the arithmetic mean of 10 values of R (rebound index) measured through the same number of percussions on a rock surface preliminarily prepared with a carborundum stone (iv) Barton comb (profilometer) and comparison profiles, as proposed by Barton and Choubey (1977), for surface roughness determination on rock discontinuities (v) Vernier caliper for the measurement of rock discontinuities aperture in a centimeter and millimeter scale (vi) flexometer in steel tape for the measurement of rock discontinuities spacing and trace length of centimetric or higher order.

Measurements may be subjected to different sources of errors, which can result in under- or over-estimation of the fracture geometrical properties (Tuckey and Stead 2016). To limit the impact of those errors, Sturzenegger and Stead (2009) suggested to couple traditional field measurements with remote sensing techniques. Indeed, techniques such as terrestrial laser scanning (TLS) and digital terrestrial photogrammetry (DTP) for rock mass characterization are increasingly being used, especially in engineering contexts where rock slopes subjected to excavation are analyzed (e.g., Kovanič and Blišťan 2014 Salvini et al. 2015 Tuckey and Stead 2016). TLS and DTP allow accurate representation of rock outcrops employing stereoscopy, 3D textured point clouds, and interpolated models. A limitation of ground-based remote sensing is related to the survey of complex topography from sub-optimal camera or scanner positions, resulting in occlusion zones (Passalacqua et al. 2015). A solution to this problem is provided by the use of UAV as a platform to acquire either optical photogrammetric images or LiDAR data. There are several photogrammetric studies where UAV is used for the geomorphic feature characterization or mapping of the surface extent in both natural and open-pit mines (Lamb 2000 Chen et al. 2015 Shahbazi et al. 2015 Tong et al. 2015 Esposito et al. 2017). Few of them deal with the use of UAV for fracture characterization of rock slopes affected by human activity. Salvini et al. (2017), for example, used UAV to map fractures in a marble quarry and, subsequently, to build 3D discrete fracture network models. McLeod et al. (2013) explored the feasibility of using UAV-acquired video images to derive 3D point clouds and to measure fracture orientations.

For describing a rock mass of steep to near-vertical rock faces, typically multirotor UAV are used since they have a vertical takeoff and landing, and they may see the study area from an optimum line of sight multirotor RPAS can allow up-and-down, or back-and-forth flight paths and camera can be oriented horizontally for taking images of very steep rock faces. Fixed-wing UAV, instead, are less utilized in this type of studies since they are not able to do up-and-down flight paths and have not the ability to hold a fixed position since their longer flight times, they tend to be used where a vertical downward orientation (nadir imaging) of the camera is desired (Tannant 2015 Giordan et al. 2015). UAV multicopters are very suited to different geometric configurations for image acquisition (i.e., zenithal, frontal, oblique) that is a crucial characteristic for rocky outcrops analysis. Multiple images obtained from different angles help the image alignment procedure and limit non-linear deformations. Moreover, the relatively short distance from rock faces to which multicopters can operate allows acquisition of high-resolution images that can be used for producing high-quality topographic products and for improving engineering-geological investigations.

In UAV SfM applications, care is needed when georeferencing the 3D model. As stated by Passalacqua et al. (2015), cameras fixed to UAV typically do not have onboard navigation systems with sufficient accuracy for geodetic positioning. The global navigation satellite system (GNSS) and inertial measurement unit (IMU), devices typically mounted on UAV, are used for navigation and flight stabilization purposes and allow only a rough estimation of airborne camera exterior orientation (Gonçalves and Henriques 2015). To obtain accurate and georeferenced 3D models, the use of ground control points (GCPs) surveyed with geodetic GNSS receivers and/or total station (TS) is generally employed (Francioni et al. 2015) and recommended. Nevertheless, the final accuracy is dependent not only on the GCP-related accuracy, density, and distribution within the surveyed area but also on image quality and percentage of overlap between single frames. TS is particularly useful for the acquisition of GCPs on vertical slopes (Menegoni et al. 2019). GCPs measured using TS and GNSS receivers can allow a high level of accuracy in the images exterior orientation, which is particularly important for subsequent fractures and rock block measurements. Therefore, careful planning of an UAV photogrammetric survey plays a crucial role in providing accurate results necessary for subsequent analysis, such as determination of fracture measurements in terms of orientation (dip direction and dip, Fig. 17), spacing, waviness and trace length.

Example of joint dip and dip direction measurement directly on the UAV-derived point cloud

The latter, in particular, is among the controlling factors that have the most significant influence on the stability condition of a block or slope, but it is challenging to be accurately determined. In this regard, UAV photogrammetric data of high resolution may play a crucial role, improving the level of knowledge of the rock mass. Recent studies by Mastrorocco et al. (2016) have also analyzed the possibility of measuring the joint roughness from RPAS-derived point clouds.

3D data from UAV SfM can be also used to perform a preliminary rockfall hazard assessment knowing the geological setting at different heights. The localized geo-structural conditions may cause different types of failures with different magnitudes. Slope stability analyses are therefore essential to improve safety conditions and management operations. However, a complete analysis of all the slopes characterizing a versant is often problematic, given their spatial extension. For this reason, both geological and geomorphological information of the whole studied area are essential to detect and evaluate the most hazardous situations. UAV-derived data should be therefore integrated with those acquired in the field from a traditional geological and engineering survey additional info as, for example, fracture resistance, infill, weathering, and water content, can only be measured by direct observation in accessible outcrops. The combined use of these data can allow preliminary 3D analysis and evaluation of the stability conditions of hazardous aspects that may be identified as posing a risk to a slope.

As demonstrated by Salvini et al. (2018), the application of UAV instrumentation can be extremely successful for the reconstruction of complex morphology in sites where ground-based techniques have limitations due to potential “shadow” effects and several inaccessible setup zones due to safety reasons.

Among the most diffuse apparatuses, also near-infrared and thermal cameras can be mounted on UAV. Near-infrared images can be used to identify minerals so to discretize rock lithologies, to investigate the homogeneity of the rock masses and to assess the humidity and weathering of the rock surface, which may indicate the presence of altered areas prone to rockfall event. The thermal camera can be adopted in areas where, in addition to common impulsive triggers (i.e., heavy rainfalls, dynamic inputs such as earthquakes or anthropic vibrations), consistent thermal excursion exists. Rock masses can react to continuous cyclical thermal inputs, which can operate on wider time-windows configuring as a preparatory factor for rock block failure. Cyclical thermally induced stresses are regarded to operate as microstructural fatigue processes responsible for mechanical weathering of the rock interface able to induce plastic strain and propagation of existing cracks (Fiorucci et al., 2018).

In addition to the described output, UAV can be used for the following measurement and mapping purposes: (i) map faults, folds, and other structures and trace them with high location and orientation accuracy (ii) calculate block volumes (iii) create contour maps and cross sections (iv) detect changes caused by erosion or slope failure using photos acquired at different times.

Apart from these opportunities, possible limitations in the use of UAV can only be related to the need for user experience both in the fields of engineering-geological survey, topographic survey, and data processing. Indeed, the accuracy of the final 3D model can be significantly affected by the quality of data collected (photos, point cloud, and GCPs), data processing, hardware, user expertise, and, lastly, software capability. It is important to remember that UAV is just a machine intended for specialized operations or for experimental, scientific or research activities, which allows an operator to bring by air a payload (such as a camera, LiDAR) to carry out a geomatic survey from an optimal point of view. In recent years, the development of SfM methods, together with rapid technological improvement, has allowed the widespread use of cost-effective UAV for acquiring repeated, detailed, and accurate geometrical information. However, the quality of results in rock mass classification and structural analysis is still necessarily dependent on in situ checks and operator knowledge.


Drone FAQ

We are frequently asked questions surrounding the general use of UAV technology and what can be achieved. The general public belief surrounding drones when we mention them in meetings etc are that they are a great tool capable of producing aesthetic imagery and promotional video. When in reality what can be achieved with a UAV is much more than that.

Of course, aesthetic video production and promotional aerial photography are a fantastic tool to assist with any company promotional or marketing projects and certainly has its place. But these services barely scrape the surface in terms of UAV function and end product.

We decided to put together a “drone FAQ” that will hopefully shed some light on the industry and how the use of drone technology can help to reduce costs and improve safety within the workplace.

Q&A Dropdown

What is the meaning behind UAV?

UAV is an acronym for Unmanned Aerial Vehicle. Those within the industry prefer the use of this term over “drone” due to the basic fact that “drone” is a term utilised by the general consumer and/or military.

What is the meaning behind RPAS?

RPAS is another acronym for “Remotely Piloted Aircraft System” again it is another term for those within the industry that prefer to use it over “drone”. It is also a more formal term used by the government and possibly public organisations.

What is the meaning behind sUAS?

The term sUAS is yet another acronym for “Small Unmanned Aerial System” again it is generally used by military personnel but often also used by professional sUAS pilots opposed to the word “drone” it can also be used without the “s” pronounce UAS (Unmanned Aerial System) although this term generally encompasses a different category of UAS which do not come under the bracket of small or sub 20kg

What is required to fly a Drone?

Anybody can operate a drone as a hobbyist as long as they adhere to the drone code and remain vigilant whilst flying. However, to operate a drone at a commercial level, you must undertake the correct training under an approved NQE. They will guide you through your ground school training and operations manual and allow you to sit an FST. This then dependent on pass rate provides you with a PfCO it is then up to yourself how you proceed.

What is the meaning of NQE?

An NQE is an abbreviation for National Qualified Entity which is a status given to a drone training company or UAV training provider facilitating operators and companies with the ability to obtain a Permissions For Commercial Operation (PfCO)

What is the meaning of PfCO?

A PfCO is an abbreviation for “Permission for Commercial Operations” which is essentially an accreditation provided by the CAA to allow a drone operator or commercial drone service company to operate commercially essentially earning money for their work.

Who or what are the CAA?

CAA is an acronym for the Civil Aviation Authority. The Civil Aviation Authority (CAA) is responsible for the regulation of aviation safety in the UK, determining policy for the use of airspace. Whether you are a commercial drone pilot, a hobbyist drone pilot or a commercial airline pilot. These guys are the governing regulatory body for all UK airspace requirements.

What is deemed as commercial operations?

The ANO defines ‘Commercial Operations’ as: Any purpose, other than commercial air transport or public transport, for which an aircraft is flown if valuable consideration is given or promised for the flight or the purpose of the flight.

This is evaluated along the lines of if any remuneration is knowingly gained from the end result of a drone flight it is essentially classed as commercial. This is can be anything from aerial photography and videography to data acquisition such as thermal or NDVI.

What is the meaning of ANO?

ANO is an abbreviation for the Air Navigation Order or CAP393 publicised by the civil aviation authority the air navigation order is a document that forms the legal basis for almost all areas of civil aviation that are regulated at national level. It is a regulatory document that encompasses all levels of aviation including drone operations.

What parts of the ANO are relavent to drone operations?

The ANO should be read in its entirety providing an overview of airspace regulations. However, there are several sections within the ANO that are relevant to UAV services. These sections are as follows.

CAP 393 The ANO:

CAP 722 Unmanned Aircraft Systems Operations UK

CAP 382 Mandatory Occurrence Reporting Scheme

What is the meaning of CAP?

CAP is an abbreviation for Civil Aviation Publication i.e “CAP 722” A “CAP is a document that is written as a regulatory document by the civil aviation authority. Offering guidance to those that occupy UK airspace.

How many categories of UAV are there?

There are several categories of unmanned aerial vehicle that are separated by their functionality but encompassed into set categories by their maximum take-off weight the different types of drone are listed below.

FIXED WING DRONE

Fixed Wing a fixed-wing drone such as the sensefly ebee is a platform that is generally utilised around mapping and spatial analysis ideally suited for BVLOS given the correct rules and regulations are adhered to.

SINGLE ROTOR DRONE

A single rotor drone is generalised around the hobbyist Single rotor drones are strong and look similar in structure and design to actual helicopters. They have one big rotor, which is like one big spinning wing, plus a small sized rotor on the tail for direction and stability.

MULTI-ROTOR DRONE

The most popular type of drones are of course quadcopters this is generally due to the ease of use and require little ability to be able to operate one proficiently, multi rotor drones can be further classified down to tricopters a platform with three props, hexacopters utilising 6 props or the larger octocopters which have 8 props and are generally classed as heavy lift due to their payload capabilities.

VTOL Vertical Take Off And Landing Drone,

A relatively new concept the VTOL drone is essentially a hybrid UAV that utilises the fixed wing system but takes off and lands using the multirotor system. The advantage being there is no longer the requirement to carry a huge launching system or hand launch.

You can further classify each system down into maximum takeoff weights as follows although there are several categories within each that may or may not require further training and permissions.

What are the limitations of drone flying in the UK?

Essentially the law requires all drone operators whether commercial or hobbyist to abide by the rules and follow the drone code. But first and foremost stay vigilant and use your common sense.

Do not fly past VLOS unless authorized, with the correct training and OSC submission resulting in further permissions issued by the CAA the general distance permitted is 500M but if you can not see that far then do not fly that far.

Do not fly above 400 ft in height or 120 m height is not the same as AMSL and should be viewed in terms of terrain if you are on a hill at 350 ft this does not mean you are limited to fly a further 50 ft, again a measure of common sense is required.

Do not operate within 150m of a congested area. The CAA class a congested area at 1000 people obviously this is an impossibility to measure so again a degree of common sense is required if you feel the area is congested then don’t fly there or ensure you have reasonable precautions in place before doing so. Preventing any issues occurring if something happens to go wrong. The 150m rule can also be reduced to 50m if an operation of a sub 20kg UAS is used.

Do not fly within 50m of any road, building, structure, vessel or person that is not under your control. This distance is looked upon as a bubble surrounding the uav and must be excersized appropriately. If you need to fly within these limits then ensure you have informed the owners of that particular asset and saught their permission prior to operating.

Do not take off or land within 30m of any road, building, structure, vessel or person that is not under your control. Again the take of and landing area should generally be marked out using correct equipment and preventing anybody from encroaching on that area.

What is the meaning of VLOS?

VLOS is an abbreviation for Visual Line Of Site and is exercised during every drone operation. The current threshold for visual line of site is 500m. There is also a fairly new term in the UAV industry call BVLOS Beyond Visual Line of Site. Which is a requirement needed during mapping of large areas or topographical surveys or land survey.

What is the meaning of an OSC?

An OSC is an acronym for operational safety case which is a document that is provided to the civil aviation authority when the pilot feels that he must operate outside of the limits provided by the CAA. The CAA will scrutinize this document prior to issuing a secondary permission which will only be issued if the CAA are satisfied that all relevant safety precautions are covered within the OSC. These one-off permissions can sometimes take up to 6months to be processed so the key is always preparation.

What does it take to start a drone business?

This is a question that we are asked on a regular basis and very rarely able to answer but we can provide a few guidelines.

There is definitely no easy route to market and certainly isn’t a get rich quick scheme, there are currently 4000+ commercial drone pilots in the UK and that number is increasing week on week.

Our advice in terms of viability is definitely along the lines of asking yourself what your USP is there is more to starting this business than buying a Mavic from the local vendor and applying for your permission.

Your drone should be looked at as a tool of the trade you currently operate in. Anybody can shell out a few thousand on equipment and go out and get their permission but then you need to consider how you approach the market that you are going to specialise in. How will you market it, how are you going to manage it? Why are you better than the guy down the road who also has a drone and PfCO?.

Do you think you can really turn up on site with a Mavic and look professional? we all know it’s about the end product and the fact that a Mavic can do just as a good a job as some of the higher end equipment but the end users opinion and judgment is what will get you another project.

There are a million different routes to consider before taking the step and we touch briefly on it in this blog post.

Can drones operate in the rain?

Drones are generally not weatherproof however DJM Aerial Solutions recently invested in a drone that can operate in inclement weather with an IP43 the Matrice M210 and Zenmuse Z30 and Zenmuse XT was a heavy investment but we are one of the few UAV service providers that are able to operate in the rain.

What is the process around each drone operation?

This is a relatively broad question but again is something we are often asked when carrying out drone operations and each project is different but if we were to carry out a basic aerial filming job.

Each project requires at least 2 hours of RAMS documentation prior to site arrival which includes the study of aviation charts and local habitation and surrounding area. This allows for us to plan and keep in close contact with any civil or military ATC units. But also gives us the required knowledge on which airspace we are planning on operating in or if there are any aviation conflicts or hazards such as HV Power transmissions or rail lines, high-intensity radio transmissions etc.

With the above info we are able to judge the requirements for the project and establish which equipment to use and what responsibilities are required, do we need a secondary observer or payload operator. Do we need a third person? Do we need to plan closure of public footpaths or roads?

A lot of people assume we can turn up on site get the machine out of the box and fly it instantly this is generally not the case and a great deal of pre-preparation is required. We first need to carry out or on-site RAMS documentation and assess any local risk, preventative measures are to be carried out preventing any public encroachment or conflict etc.

Pre-flight assessment of the drone is then necessary giving the pilot the confidence to be able to fly knowing that there are no problems with the aircraft and everything is working as it should.

The flying is sometimes risky and the drone pilot needs to be vigilant continuously monitoring the telemetry data, ensuring sufficient battery power in both UAV and RC, occasional checks of GPS data to ensure satellite coverage is sufficient and there is no requirement to fly in ATTI mode. But also watching the drone at all times to allow for recovery if an uncontrolled movement is observed.

This is all carried out at the same time as operating the camera and adjusting parameters and settings, changing lenses, altering shutter speeds and frame rates. Installing filters and lens hoods etc.

Once this has been taken care of and the aerial videography is complete post-flight inspection is necessary checking for any issues that require attention, logging flight duration, and battery life but also debriefing the ground team and ensuring all the required date was acquired.

Once the drones and equipment have been packed away and team debriefed the next option is to upload the data onto a computer and carry out the relevant editing requirements this is the time-consuming area utilising relevant editing suites, colour grading each section, clipping and cropping hours of film and then putting it all together with a relevant audio and possible inro and end titles. Then rendering it into a useable format and providing an initial edit for the client to review which then may require further editing and the process starts again.

How much does it cost?

Again a very broad question and unfortunately not an easy one to answer as if operation differs entirely from the next and depends on the end product and what is required.

For instance, if we are working for a corporate blue chip company that might require a thermal inspection of an asset onsite, the cost would be very different to somebody that requires a quarterly progressional report for a construction development. Which again would differ from a promotional aerial video or image.

The best and easiest way for us to assess your project in terms of pricing is to contact us for a free no obligation quote

How did you start your drone service business?

As a hobbyist photographer, I have had several entry-level drones over the years for personal use. But as the technology increased several companies began using them for commercial gain. I was working overseas as an engineer at the time longing to spend more time with my family.

I decided to invest in my PfCO after understanding that there was a possibility of me being able to use drone technology as an extension of my eyes assisting in any preventive or reactive maintenance routines.

Visual inspection and survey was a big part of my professional life during my career and more often than not required a great deal of paperwork and long-term isolation prior to carrying out the task. If I could reduce the time required to carry out visual survey, which is an essential part of any maintenance routine then I could also reduce the financial overheads of these companies.

This was the base plan for my business model. I am able to bring my experience in the field as an engineer to carry out a more targeted inspection routine. I knew I could interpret the data essentially being able to fault find any issues from this high resolution or thermographic data and had 20+ years experience in report writing post data capture.

However, I also understood that a huge financial investment from myself would be required as these blue-chip companies would never take me seriously turning up on site with a consumer level entry grade drone.

Its been a hard road and we expected it. So if I was to give any advice I would suggest that you research your market and use the machine as part of your toolbox opposed to going into it the trade blind.

What do you use your drones for?

There are so many uses for drones currently and more are being developed on a daily basis. It is essentially a disruptive innovation with plenty of investment from third parties and government bodies.We have come up with a list of the more popular services that we can achieve.

Drone Aerial Inspection

We specialise in asset integrity inspection and survey which is where our background lies within industry. The UAV lends itself particularly well to this in an industry that concentrates much of its time on safety improvements whilst trying new techniques to remain cost-effective.

Drone Thermographic Aerial Survey

Again we utilise thermal imaging sensors alongside standard RGB sensors which can be used to inspect for energy loss across a wide range of assets. They can be used to check for leakage across pipework, heat buildup in rotating equipment which might indicate failing components, building envelope inspections to check for permeation of insulation, excessive heat build up in electrical components which could indicate premature failure.

Long Range Asset Inspection

We have access to one of the most powerful RGB cameras on the market the zenmuse z30 this RGB camera is capable of producing high-resolution images from up to 150m distance with it 180 x zoom function. The main reason we use this is to provide close up inspection routines on industrial assets that might generally require shut down or isolation prior to carrying out the inspection. It could also be used as an inspection tool where assets require inspection which might be within a sensitive area on site.

Land Survey and Topographical Survey.

Drones are fast becoming the go-to choice for any land survey work obviously the immediate benefit being their ability to cover ground a great deal faster than traditional methods using a total station or theodolite. The end result can also be tied into pre-positioned ground control points giving an accurate reference when designing and constructing any new development.

3D Imaging and Point Cloud Analysis

As with the above drones are fast becoming the go-to choice for point cloud and 3d image development due to the speed and lack of limitations that are evident and the final product is usually better than the alternative. 3D modeling is a fantastic way to monitor maintenance routines on the likes of heritage sites or construction maintenance and can be used as a reference towards new construction developments. Point clouds are made up of a series of data points captured using overlapping images and referenced with the XYZ coordinates. They can be used to depict relative measurements or elevations and deviations and are a fantastic tool for surveyors.

Internal Inspection and Confined Space Survey

Storage tank inspection is a relatively enormous task generally speaking with the requirement to carry out several safety checks prior to entry all of which are detailed here DJM Aerial solutions now have access to a tank inspection drone or confined space inspection UAV that can not only m provide a colossal reduction in the overall the time taken to carry out this same task. But also provide a much safer alternative. With the ability to capture both standard RGB and thermal data.

Promotional Aerial Video / Aerial Photography

This speaks for itself in terms of functionality we are often asked to produce aerial video and or photography for companies that would like to promote their business or an upcoming event. We have the experience behind a camera and the equipment to create bespoke aerial footage for your promotional needs

Construction Development Progressional Reports

Another recently popular task is to provide monthly footage or imagery or new build construction developments that can be assigned to a progressional report and handed over to relevant shareholders, providing them with the required evidence that their investment is “developing” over time.

What are your camera specifications?

We have several Cameras or payloads and all are based on different services. Listed below with their parent UAV:

DJI Phantom 4

DJI Phantom 4 Pro

Sensor 1’’ CMOS
Effective pixels: 20M
Lens FOV 84° 8.8 mm/24 mm (35 mm format equivalent) f/2.8 – f/11 auto focus at 1 m – ∞
ISO Range Video:
100 – 3200 (Auto)
100 – 6400 (Manual)
Photo:
100 – 3200 (Auto)
100- 12800 (Manual)
Mechanical Shutter Speed 8 – 1/2000 s
Electronic Shutter Speed 8 – 1/8000 s
Image Size 3:2 Aspect Ratio: 5472 × 3648
4:3 Aspect Ratio: 4864 × 3648
16:9 Aspect Ratio: 5472 × 3078
PIV Image Size 4096×2160(4096×2160 24/25/30/48/50p)
3840×2160(3840×2160 24/25/30/48/50/60p)
2720×1530(2720×1530 24/25/30/48/50/60p)
1920×1080(1920×1080 24/25/30/48/50/60/120p)
1280×720(1280×720 24/25/30/48/50/60/120p)
Still Photography Modes Single Shot
Burst Shooting: 3/5/7/10/14 frames
Auto Exposure Bracketing (AEB): 3/5 bracketed frames at 0.7 EV Bias
Interval: 2/3/5/7/10/15/20/30/60 s
Video Recording Modes H.265
C4K:4096×2160 24/25/30p @100Mbps
4K:3840×2160 24/25/30p @100Mbps
2.7K:2720×1530 24/25/30p @65Mbps
2.7K:2720×1530 48/50/60p @80Mbps
FHD:1920×1080 24/25/30p @50Mbps
FHD:1920×1080 48/50/60p @65Mbps
FHD:1920×1080 120p @100Mbps
HD:1280×720 24/25/30p @25Mbps
HD:1280×720 48/50/60p @35Mbps
HD:1280×720 120p @60MbpsH.264
C4K:4096×2160 24/25/30/48/50/60p @100Mbps
4K:3840×2160 24/25/30/48/50/60p @100Mbps
2.7K:2720×1530 24/25/30p @80Mbps
2.7K:2720×1530 48/50/60p @100Mbps
FHD:1920×1080 24/25/30p @60Mbps
FHD:1920×1080 48/50/60 @80Mbps
FHD:1920×1080 120p @100Mbps
HD:1280×720 24/25/30p @30Mbps
HD:1280×720 48/50/60p @45Mbps
HD:1280×720 120p @80Mbps
Max Video Bitrate 100 Mbps
Supported File Systems FAT32 (≤32 GB) exFAT (>32 GB)
Photo JPEG, DNG (RAW), JPEG + DNG
Video MP4/MOV (AVC/H.264 HEVC/H.265)
Supported SD Cards Micro SD
Max Capacity: 128GB
Write speed ≥15MB/s, Class 10 or UHS-1 rating required
Operating Temperature Range 32° to 104°F (0° to 40°C)

DJI Inspire 1 Pro Zenmuse X5

SENSOR

MAX-PIXELS

Exposure P/S/A/M
AE Metering Auto/spot metering
AE Lock Support
WB auto/manual/spot
Focus Mode AFS/AFF/MFT
Focus Mode 256-zone / Pinpoint/(Touch focus is available)
AF AUX Support
AE Lock Yes (AF/AE LOCK button)
Focus Peaking Support
Zebra Support
Adjustment Support
Style sRGB,Color looks, LOG, Cine-D
Enhancement HDR/Video DR
Software N/A
Optics User Selectable (default DJI MFT 15mm F/1.7 ASPH)
Iris F/1.7-F/16 (default DJI lens)
Diagonal FOV 72 degree (default DJI lens)
Equivalent 30mm (default DJI lens)
Distortion 0.40%
Focus Range 20cm-infinite (default DJI lens)
Auto-Focus Support (default DJI lens)

VIDEO

Resolution 4096�(23.98p)
3840�(29.97/23.98p)
2704�(30/25P)
1920�(59.94/29.97p)
Encoder MPEG4/AVC/H.264
Max-Bitrate [email protected]�(23.98p)
[email protected]�(29.97/23.98p)
[email protected]�(30/25p)
[email protected]�(59.94p)
[email protected]�(29.97p)
Format MP4/MOV
Storage Micro-SD Class 10
Video NR Support
Stabilizer Support

DJI Matrice M210

Zenmuse X5S

GENERAL

CAMERA

Supported Lens DJI MFT 15mm/1.7 ASPH (With Balancing Ring and Lens Hood)
Panasonic Lumix 15mm/1.7 (With Balancing Ring and Lens Hood)
Panasonic Lumix 14-42mm/3.5-5.6 HD
Olympus M.Zuiko 12mm/2.0 (With Balancing Ring)
Olympus M.Zuiko 17mm/1.8 (With Balancing Ring)
Olympus M.Zuiko 25mm/1.8
Olympus M.Zuiko 45mm/1.8
Olympus M.Zuiko 9-18mm/4.0-5.6
Sensor CMOS, 4/3”
Effective Pixels: 20.8MP
FOV 72° (with DJI MFT 15mm/1.7 ASPH )
Photo Resolutions 4:3, 5280×3956
16:9, 5280×2970
Video Resolutions Aspect Ratio 17:9

CinemaDNG
4K DCI: 4096×2160 23.976/24/25/29.97p,
up to 2.4Gbps 50/59.94p, up to 4.0Gbps

H.264
4K DCI: 4096×2160 23.976/24/25/29.97/47.95/50/59.94p @100Mbps

H.265
4K DCI: 4096×2160 23.976/24/25/29.97p @100Mbps

CinemaDNG
4K Ultra HD: 3840×2160 23.976/24/25/29.97p,
up to 2.4Gbps 50/59.94p, up to 4.0Gbps

ProRes
4K Ultra HD: 3840×2160 23.976/24/25/29.97p,
422 HQ @900Mbps 23.976/24/25/29.97p, 4444 XQ @2.0Gbps

H.264
4K Ultra HD: 3840×2160 23.976/24/25/29.97/47.95/50/59.94p @100Mbps
2.7K: 2720×1530 23.976/24/25/29.97p @80Mbps 47.95/50/59.94p @100Mbps
FHD: 1920×1080 23.976/24/25/29.97p @60Mbps
47.95/50/59.94p @80Mbps 119.88p @100Mbps

H.265
4K Ultra HD: 3840×2160 23.976/24/25/29.97p @100Mbps
2.7K: 2720×1530 23.976/24/25/29.97p @65Mbps
47.95/50/59.94p @80Mbps
FHD: 1920×1080 23.976/24/25/29.97p @50Mbps
47.95/50/59.94p @65Mbps 119.88p @100Mbps

CinemaDNG
5.2K: 5280×2972 23.976/24/25/29.97p, up to 4.2Gbps


RELATED ARTICLES

The lines can't be seen from the ground, according to the researchers, with Valenzuela saying 'this may be significant'.

Adding that it may imply that their significant came from the act of creation, not later viewing by future people.

The study authors wrote in their paper: 'Three memorial stones positioned at key points, give evidence that planimetric knowledge has been used to create this elaborate design.'

Planimetric elements in geography are features independent of elevation - roads, rivers, lakes and buildings.

The lines make up four distinct symbols, created by scraping sand and silt near the village of Boha, with the largest single symbol 2,374ft long and 650ft wide, made of a single seven and a half mile line spiralling inwards

Study authors, not affiliated with any institution, say the lines are at least 150 years old, but can't say anything more specific, adding their meaning is lost to history.

'These artefacts allow us to envisage hypothetical modalities of edification,' the authors wrote.

'We collected indicators of antiquity suggesting that these lines may be at least 150 years old and possibly linked to the Hindu memorial stones surrounding them.

'The lack of visibility from the ground raises the question of their function and meaning. So far, these geoglyphs, the largest discovered worldwide and for the first time in the Indian subcontinent, are also unique as regards their enigmatic signs.'

In the case of the Nazca line geoglyphs, they were likely created by people removing the black topsoil to reveal light-coloured sand hidden underneath.

The spiral artwork is made up of a series of small geoglyphs covering an area of about a million square feet in the Thar desert in India, first spotted on Google Earth by Carlo and Yohann Oetheimer, a father and son research team from France

The lines can't be seen from the ground, according to the researchers, with Valenzuela saying 'this may be significant'

Geoglyphs span large land tracts located between the towns of Palpa and Nazca, and some depict animals, objects or compact shapes.

Often, the composition of a geoglyph cannot be fully realised at ground level. Only when one is high enough in the air can they discern the shapes.

For this reason the intricacies of the designs were not fully realised until aeroplanes were invented and the artwork was seen from the sky.

'We will need to go to India in the near future in order to complete our research and have a precise dating, in order to understand their function and meaning better. For now, the dating is hypothetical,' Carlo Oetheimer told MailOnline.

The findings have been published in the journal Archaeological Research in Asia.

WHAT ARE PERU'S MYSTERIOUS 'NAZCA LINES'?

Geoglyphs span large land tracts located between the towns of Palpa and Nazca. Some geoglyphs depict animals, objects or compact shapes others are only simplistic lines.

The Nazca people lived in the area from 200 to 700 CE. Some of the designs are believed to be created instead by the Topará and Paracas people.

Most of the lines are formed by a shallow trench with a depth of between four inches (10cm) and six inches (15cm), made by removing the reddish-brown iron oxide-coated pebbles that cover the surface of the Nazca desert and exposing the light-colored earth beneath.

This sublayer contains high amounts of lime which has hardened to form a protective layer that shields the lines from winds and prevents erosion.

An aerial view of a spiral-tailed monkey figure in Peru's mysterious Nazca Lines, located some 240 miles south of Lima. No one knows why the Pre-Inca Nazca culture made the figures and lines, some of them miles long

Paul Kosok, from Long Island University, is credited as the first scholar to seriously study the Nazca Lines.

He discovered that the lines converged at the winter solstice in the Southern Hemisphere.

Along with Maria Reiche, a German mathematician and archaeologist, Kosok proposed the figures were markers on the horizon to show where the sun and other celestial bodies rose.


Watch the video: ΝΙΚΟΣ ΓΩΝΙΑΝΑΚΗΣ - ΤΟ ΧΩΡΙΑΝΑΚΙ ΣΥΡΤΑ (November 2021).