The NUSO performed its first UAS missions this year, starting with a February mission in restricted air space during a prescribed wildfire burn exercise at the Eglin Airforce Base in Florida, followed in March by its first mission in civilian air space to perform Sandhill Crane population counts at Colorado’s Monte Vista National Wildlife Refuge.
Inspections at West Virginia Contour Surface Coal Mines
Between 2011 and 2013 the NUSO performed three UAS missions, in coordination with the Office of Surface Mining, at the Powellton Surface Mine to test the utility of UAS technology for supporting coal mining inspection and oversight.
![USGS scientist hand launching a fixed wing UAS](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/media/images/uasWVCoalMraven-8142410659.jpg?itok=ye6-bxNJ)
State and Federal employees are responsible for inspecting mine sites to monitor conditions like water quality, hazardous conditions, terrain topology, wildlife habitats, post mining land use, and ensuring that operational requirements are being met. For example, each coalmine is required to have drainage control structures internally and around the perimeter of the mine area to control runoff and prevent flooding. Underground mine fires must also be located and monitored even when very little information is known including potentially the location and extent. Performance of these activities, especially in areas like West Virginia that has over 1800 coal mines, requires vast amounts of time traversing rough terrain often hazardous to both staff and equipment.
The Powellton Mine is a contour surface mine that has several miles of installed drainage/sediment ditches and two known underground mine fires, which made it an ideal location to test UAS as a tool for performing inspections. The Raven platform was used in the first mission in November 2011, but later missions utilized the newer T-Hawk platform with higher resolution GoPro and Canon cameras for on-broad data capture. The T-Hawk quickly became the preferred platform based on its ability to hover and increased mobility when flying in tighter areas with steep terrain.
Data acquired during these missions included the video files from the onboard camera systems captured real-time during the flight missions, as well as the high resolution still frame images captured from both the Canon and the GoPro. Since visual inspection for compliance was the primary objective, images captured at oblique angles were determined to be as valuable as the vertical imagery. Either vertical or oblique imagery can be used for 3D modeling of the mining areas, as well as perimeter and volumetric measurements, through use of the photogrammetric post-processing software.
These successful missions at West Virginia coal mines demonstrated UAS technology as an efficient new tool for surface mine inspection and monitoring. The data collected, from real-time video feeds to rectified imagery, was shown to aid inspectors in monitoring the vast areas of surface mines they are responsible for overseeing annually. The imagery was also proven to be an effective method for capturing coal-seam fire locations and extent. Valuable secondary products, such as 3D modeling, reclamation ground measurements, time-series investigations, color infrared images for seep detection, and geo-rectified base images, could also be derived from the low-altitude imagery.
Study Points of Contact:
Lukus J. Monette, Remote Sensing Specialist
U.S. Office of Surface Mining, Appalachian Regional Office
Jeff Sloan, Physical Scientist
USGS NUSO, Geosciences and Environmental Change Science Center
Monitor Shoreline Erosion along the Missouri River on the Lower Brule Reservation
In August of 2011 and 2012 the NUSO worked with the Lower Brule Sioux Tribe (LBST) Environmental Protection Office to evaluate UAS’s ability to safely collect data along dangerous or even inaccessible shoreline.
![Fixed wing UAS being hand launched from a boat on the Missouri River](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/media/images/uasSDMoRraven-8141985337.jpg?itok=YqKdxrNc)
The LBST, home to approximately 600 Native Americans, is located on the western side of the Missouri River in central South Dakota. The Missouri River and the two lakes formed by dams, Lake Sharpe and Lake Francis Case, form the northern and eastern boundary of the LBST Reservation which can see shoreline erosion occur at a rate of approximately 8 feet per year. This high rate of erosion threatens the many ancestral sites located along the Missouri River, as well as agriculture and recreational activities that are a large part of the LBST Reservation's economy. To better evaluate the impacts of erosion the LBST Environmental Protection Office implemented a two-year monitoring program of a 7-mile stretch of the Missouri River's shoreline experiencing a high rate of bank loss and is also the location of the LBST rural water plant's intake. However, since direct shoreline access in this area is hampered by lack of roads, crumbling riverbanks and shallow water unsuitable for motorboat traffic, it was decided to use UAS to collect the shoreline data needed for the monitoring efforts.
During these missions the Raven platform was able to safely and easily access this remote shoreline by being hand launched from either land away from the shoreline, or a motorboat located offshore. The Raven successfully captured video imagery along the shoreline with its original FMV analog sensor, which was the only UAS sensor available at this time. Once collected this relatively low-resolution video was used to derive still frame photography that was then geo-referenced with existing base imagery and mosaicked together to create seamless rectified imagery of the shoreline. After completion of this same process for the data acquired during the flights in 2012, two-years of rectified and oblique imagery over the same riverbank erosion areas provided a time-series to aid in land management decisions.
As a result of these missions the NUSO showcased the value of UAS for acquiring data to analyze shoreline erosion and operate as a safe and economical tool for monitoring inaccessible or dangerous shoreline.
Study Point of Contact:
Kathy Neitzert, Hydrologist
SDWSC Huron Programs Office
Additional Information:
Drones Across America, Discovery News article highlights USGS UAS Office and Lower Brule Sioux Tribe (LBST) Environmental Protection Office use of UAS technology to monitor Missouri Riverbank erosion. - August 2012.
Ground Water Discharge Monitoring at Montana’s Red Rock Lakes National Wildlife Refuge
The NUSO performed a mission in August of 2011 to determine if the Raven UAS thermal sensors could be used to identify areas of ground water discharge.
![UAS ground control station at the Red Rock Lakes National Wildlife Refuge](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/media/images/uasMTGWtrgrdopsimg0196-8142367725.jpg?itok=sb5oWeI6)
Although these thermal sensors are not calibrated, they could still be useful by showing relative temperature differences adequate for mapping the extents of the discharge areas within the lake water bodies or near the shoreline. This was based on the premise that since all discharge water is about 15 degrees Celsius colder than the shallow lake water during mid to late summer, thermal infrared imagery should be able to detect this temperature contrast. This would allow areas of focused groundwater discharge to be identified and detailed measurements of rates of discharge to be made for quantification of this focused groundwater discharge.
Red Rock Lakes National Wildlife Refuge (NWR) contains one of the few marshland wilderness areas in the country and is host to a population of rare trumpeter swans. Groundwater discharge to Upper and Lower Red Rock Lakes and the wetlands in between are a large component of the marshland water budget. However, the volume and distribution of groundwater discharge remain unknown, even though understanding the volume, distribution, and temporal variability of groundwater discharge is critical to management of the natural resources of this refuge and wilderness area.
After the data was collected evaluation of the thermal imagery successfully identified several springs in the near-shore margins of Upper Red Rock Lake. Some of these springs discharged on land adjacent to the lake and then flowed overland into the lake, while others discharged in shallow water within several hundred meters of the shoreline. In addition, some of these springs were readily visible in the thermal imagery as distinct holes in the lakebed, whereas others were harder to identify. As a result, it was determined that relative temperature differences, particularly in water bodies, are easy to detect with UAS thermal infrared sensors making this technology a useful tool for mapping groundwater discharge point and distribution. Further, time-series studies could also be employed, through multiple collects over time, to display the perennial or intermittent nature of the flow.
Study Point of Contact:
Donald Rosenberry, Project Chief
USGS National Research Program, Central Branch
Pygmy Rabbit Habitat Study in the Idaho Desert between Shoshone and Hailey
NUSO researchers partnered with Boise State University and the University of Idaho in June and July of 2011 to determine if UAS technology could be used to gather data on the landscape habitat of pygmy rabbits.
![USGS researcher monitoring the flight of a UAS](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/side_image/public/media/images/uasIDPyggrdopsp6300367-15940411612.jpg?itok=PQdooNo3)
Pygmy rabbits dig extensive burrow systems in areas with large sagebrush, particularly mature stands, and loss of habitat is a direct threat to the species. These rabbits are also an important food source for the many other animals in the area, with birds and other mammals being primary predators. Unfortunately, over time the rabbit's habitat has become increasingly fragmented by development, agriculture, fire and rangeland "improvements", e.g., projects that replace big sagebrush with bunchgrasses.
During this mission several low altitude Raven flights were used to capture high-resolution electro-optical data that was later used to produce a base layer of rectified imagery as a tool for analyzing pygmy rabbit habitats. This image product was also used to develop and field-test spatially explicit models (e.g., mixed spatial regression models and hierarchical Bayesian models) depicting how vegetation cover, diet quality, and temperatures influence habitat use by pygmy rabbits. This represents a novel approach since it provides a multivariate, multi-scale empirical link between theoretical predictions of the effects and interactions of multiple environmental stressors on the functional responses by pygmy rabbits.
Although this imagery layer is just one input into a much larger GIS model, it represents data that has not previously been possible to attain. Use of UAS technology shows great promise in establishing new models that will aid in wildlife conservation.
Study Points of Contact:
Dr. Jennifer Forbey, Biology Professor
Boise State University
Jeff Sloan, Physical Scientist
USGS NUSO, Geosciences and Environmental Change Science Center
Sandhill Crane Population Estimates at the Monte Vista National Wildlife Refuge
In March 2011 the NUSO, in cooperation with the U.S. Fish and Wildlife Service (USFWS), performed its first UAS mission in civilian air space at the Monte Vista NWR in Colorado to study the feasibility of using UAS sensors to survey Sandhill cranes.
![Image of Sandhill cranes roosting site in the Monte Vista NWR taken from a UAS](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/media/images/uasCOSandhillCravengopr4601-8643017491.jpg?itok=5MrQfBQA)
The USFWS, mandated by Migratory Bird rules and regulation, is responsible for performing periodic surveys of the Sandhill crane population. Sandhill cranes are migratory birds that travel from Texas to Idaho (or as far as Siberia) annually and the Monte Vista NWR serves as a major stopover point during migration, making it a perfect location for conducting accurate population counts. These surveys are traditionally conducted by using fixed-wing aircraft, which can place both birds and staff at risk of mid-air collisions, or time-consuming ground-count methods, where biologists in the field attempt to visually enumerate the birds with sectional surveys. Although these methods produce the required information, they also introduce both safety and cost concerns, which made this a perfect choice for a UAS proof of concept mission.
As part of the planning process for this first UAS mission, NUSO had to establish and perform operational procedures to obtain FAA COA and radio spectrum approvals. The FAA COA process started on July 9, 2010, and the final approval was received six months later December 27, 2010. Specifications in the approved COA required that all Raven flights remain below 400 feet AGL, within visual line of sight of authorized trained observers and occur between morning civil twilight to evening civil twilight.
Determining if the Raven sensor could pick up the heat signature of the cranes in enough detail to allow biologists to obtain accurate counts was the main objective of this mission. But equally important was determining how the cranes would react to the Raven, especially since there were concerns that the cranes would see the Raven as an eagle, a major predator, and flush/fly away when it approached. To minimize any potential disruption to the cranes the plan was to fly the Raven at high altitudes or at night when the cranes were at roost. These plans had to be revised when the approved COA included both altitude and flight time limitations so also considering that most cranes depart the roost at or shortly after sunrise, flights were planned during the approximate 30-minute time frame between civil twilight and sunrise.
Safe completion of these initial flights clearly demonstrated that the Raven UAS could be flown without disruption to the cranes, and that the sensor payloads could identify their heat signatures. This left only the question of whether this data could be used to provide accurate population counts. In order to answer this final question population counts were first derived from the imagery captured by the Raven sensors. This was done by using mosaicking software to process the video into a single image of the complete roosting area. Next the easily identified heat signatures were counted and a Raven derived population count was established. This population count was then compared to a count established by the USFWS prior to the Raven mission during a ground-count to get an 'observed' population count, as well as to verify the location of the cranes within their roosting area. Results of this comparison between the ground based and UAS data derived population counts resulted in a 4.6% difference, which was determined to be acceptable.
These results established that utilizing UAS to perform population counts for Sandhill cranes is safe and produces accurate results. In fact, Dave Sharp, a retired USFWS biologist who has been working with the Sandhill cranes for over 25 years, said "I was skeptical about this process at first, but it has exceeded my wildest expectations". When asked if Raven video could be used to validate their counts, another biologist said that it was the other way around: his count will be used to validate the Raven's - "the Raven found birds that we did not know were there." The Refuge Manager, Floyd Truetken, said "I would like Raven and the team to come back to my refuge next year and they can come and train anytime. I would definitely recommend them to other refuge managers and biologists." There was 100% agreement among the scientists that this technology will revolutionize the way wildlife counts and tracking are conducted in the future.
Successful completion of this first mission also led to the NUSO being given approval from the FAA to perform night flights during later Raven missions performed in November 2011, March 2012, and March 2013. As a result of these additional missions, it was determined that Raven imagery provides acceptable population counts without disruption to the cranes, especially when flown at night when the cranes are at rest in the roosting areas.
Additional Information:
A Drone's-Eye View of Nature - New York Times
USGS Takes to the Sky - Earth Imaging Journal Article September/October 2011
Monitor Prescribed Wildfire Burns at Florida’s Eglin Airforce Base
![Remote pilot preparing to hand launch a fixed wing UAS during a prescribed wildfire burn in Florida](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/media/images/uasFLElginraven-8122752121.jpg?itok=FiYOpYKk)
In cooperation with the U.S. Forest Service, the NUSO conducted its first UAS flights in the United States during a prescribed burn at the Prescribed Fire Combustion and Atmospheric Dynamics Research Experiment (RxCADRE) event in February 2011.
Since this prescribed burn was at the Eglin Air Force Base in Florida all UAS operations occurred within military air space (versus civilian air space) which meant that no FAA or additional flight approvals were required. NUSO pilots successfully flew the Raven, one of the three UAS platforms flown, and demonstrated its ability to stream live thermal IR and natural color video to the fire command center to support fire management and operations.
Study Point of Contact:
Jeff Sloan, Physical Scientist
USGS NUSO, Geosciences and Environmental Change Science Center
The NUSO performed its first UAS missions this year, starting with a February mission in restricted air space during a prescribed wildfire burn exercise at the Eglin Airforce Base in Florida, followed in March by its first mission in civilian air space to perform Sandhill Crane population counts at Colorado’s Monte Vista National Wildlife Refuge.
Inspections at West Virginia Contour Surface Coal Mines
Between 2011 and 2013 the NUSO performed three UAS missions, in coordination with the Office of Surface Mining, at the Powellton Surface Mine to test the utility of UAS technology for supporting coal mining inspection and oversight.
![USGS scientist hand launching a fixed wing UAS](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/media/images/uasWVCoalMraven-8142410659.jpg?itok=ye6-bxNJ)
State and Federal employees are responsible for inspecting mine sites to monitor conditions like water quality, hazardous conditions, terrain topology, wildlife habitats, post mining land use, and ensuring that operational requirements are being met. For example, each coalmine is required to have drainage control structures internally and around the perimeter of the mine area to control runoff and prevent flooding. Underground mine fires must also be located and monitored even when very little information is known including potentially the location and extent. Performance of these activities, especially in areas like West Virginia that has over 1800 coal mines, requires vast amounts of time traversing rough terrain often hazardous to both staff and equipment.
The Powellton Mine is a contour surface mine that has several miles of installed drainage/sediment ditches and two known underground mine fires, which made it an ideal location to test UAS as a tool for performing inspections. The Raven platform was used in the first mission in November 2011, but later missions utilized the newer T-Hawk platform with higher resolution GoPro and Canon cameras for on-broad data capture. The T-Hawk quickly became the preferred platform based on its ability to hover and increased mobility when flying in tighter areas with steep terrain.
Data acquired during these missions included the video files from the onboard camera systems captured real-time during the flight missions, as well as the high resolution still frame images captured from both the Canon and the GoPro. Since visual inspection for compliance was the primary objective, images captured at oblique angles were determined to be as valuable as the vertical imagery. Either vertical or oblique imagery can be used for 3D modeling of the mining areas, as well as perimeter and volumetric measurements, through use of the photogrammetric post-processing software.
These successful missions at West Virginia coal mines demonstrated UAS technology as an efficient new tool for surface mine inspection and monitoring. The data collected, from real-time video feeds to rectified imagery, was shown to aid inspectors in monitoring the vast areas of surface mines they are responsible for overseeing annually. The imagery was also proven to be an effective method for capturing coal-seam fire locations and extent. Valuable secondary products, such as 3D modeling, reclamation ground measurements, time-series investigations, color infrared images for seep detection, and geo-rectified base images, could also be derived from the low-altitude imagery.
Study Points of Contact:
Lukus J. Monette, Remote Sensing Specialist
U.S. Office of Surface Mining, Appalachian Regional Office
Jeff Sloan, Physical Scientist
USGS NUSO, Geosciences and Environmental Change Science Center
Monitor Shoreline Erosion along the Missouri River on the Lower Brule Reservation
In August of 2011 and 2012 the NUSO worked with the Lower Brule Sioux Tribe (LBST) Environmental Protection Office to evaluate UAS’s ability to safely collect data along dangerous or even inaccessible shoreline.
![Fixed wing UAS being hand launched from a boat on the Missouri River](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/media/images/uasSDMoRraven-8141985337.jpg?itok=YqKdxrNc)
The LBST, home to approximately 600 Native Americans, is located on the western side of the Missouri River in central South Dakota. The Missouri River and the two lakes formed by dams, Lake Sharpe and Lake Francis Case, form the northern and eastern boundary of the LBST Reservation which can see shoreline erosion occur at a rate of approximately 8 feet per year. This high rate of erosion threatens the many ancestral sites located along the Missouri River, as well as agriculture and recreational activities that are a large part of the LBST Reservation's economy. To better evaluate the impacts of erosion the LBST Environmental Protection Office implemented a two-year monitoring program of a 7-mile stretch of the Missouri River's shoreline experiencing a high rate of bank loss and is also the location of the LBST rural water plant's intake. However, since direct shoreline access in this area is hampered by lack of roads, crumbling riverbanks and shallow water unsuitable for motorboat traffic, it was decided to use UAS to collect the shoreline data needed for the monitoring efforts.
During these missions the Raven platform was able to safely and easily access this remote shoreline by being hand launched from either land away from the shoreline, or a motorboat located offshore. The Raven successfully captured video imagery along the shoreline with its original FMV analog sensor, which was the only UAS sensor available at this time. Once collected this relatively low-resolution video was used to derive still frame photography that was then geo-referenced with existing base imagery and mosaicked together to create seamless rectified imagery of the shoreline. After completion of this same process for the data acquired during the flights in 2012, two-years of rectified and oblique imagery over the same riverbank erosion areas provided a time-series to aid in land management decisions.
As a result of these missions the NUSO showcased the value of UAS for acquiring data to analyze shoreline erosion and operate as a safe and economical tool for monitoring inaccessible or dangerous shoreline.
Study Point of Contact:
Kathy Neitzert, Hydrologist
SDWSC Huron Programs Office
Additional Information:
Drones Across America, Discovery News article highlights USGS UAS Office and Lower Brule Sioux Tribe (LBST) Environmental Protection Office use of UAS technology to monitor Missouri Riverbank erosion. - August 2012.
Ground Water Discharge Monitoring at Montana’s Red Rock Lakes National Wildlife Refuge
The NUSO performed a mission in August of 2011 to determine if the Raven UAS thermal sensors could be used to identify areas of ground water discharge.
![UAS ground control station at the Red Rock Lakes National Wildlife Refuge](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/media/images/uasMTGWtrgrdopsimg0196-8142367725.jpg?itok=sb5oWeI6)
Although these thermal sensors are not calibrated, they could still be useful by showing relative temperature differences adequate for mapping the extents of the discharge areas within the lake water bodies or near the shoreline. This was based on the premise that since all discharge water is about 15 degrees Celsius colder than the shallow lake water during mid to late summer, thermal infrared imagery should be able to detect this temperature contrast. This would allow areas of focused groundwater discharge to be identified and detailed measurements of rates of discharge to be made for quantification of this focused groundwater discharge.
Red Rock Lakes National Wildlife Refuge (NWR) contains one of the few marshland wilderness areas in the country and is host to a population of rare trumpeter swans. Groundwater discharge to Upper and Lower Red Rock Lakes and the wetlands in between are a large component of the marshland water budget. However, the volume and distribution of groundwater discharge remain unknown, even though understanding the volume, distribution, and temporal variability of groundwater discharge is critical to management of the natural resources of this refuge and wilderness area.
After the data was collected evaluation of the thermal imagery successfully identified several springs in the near-shore margins of Upper Red Rock Lake. Some of these springs discharged on land adjacent to the lake and then flowed overland into the lake, while others discharged in shallow water within several hundred meters of the shoreline. In addition, some of these springs were readily visible in the thermal imagery as distinct holes in the lakebed, whereas others were harder to identify. As a result, it was determined that relative temperature differences, particularly in water bodies, are easy to detect with UAS thermal infrared sensors making this technology a useful tool for mapping groundwater discharge point and distribution. Further, time-series studies could also be employed, through multiple collects over time, to display the perennial or intermittent nature of the flow.
Study Point of Contact:
Donald Rosenberry, Project Chief
USGS National Research Program, Central Branch
Pygmy Rabbit Habitat Study in the Idaho Desert between Shoshone and Hailey
NUSO researchers partnered with Boise State University and the University of Idaho in June and July of 2011 to determine if UAS technology could be used to gather data on the landscape habitat of pygmy rabbits.
![USGS researcher monitoring the flight of a UAS](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/side_image/public/media/images/uasIDPyggrdopsp6300367-15940411612.jpg?itok=PQdooNo3)
Pygmy rabbits dig extensive burrow systems in areas with large sagebrush, particularly mature stands, and loss of habitat is a direct threat to the species. These rabbits are also an important food source for the many other animals in the area, with birds and other mammals being primary predators. Unfortunately, over time the rabbit's habitat has become increasingly fragmented by development, agriculture, fire and rangeland "improvements", e.g., projects that replace big sagebrush with bunchgrasses.
During this mission several low altitude Raven flights were used to capture high-resolution electro-optical data that was later used to produce a base layer of rectified imagery as a tool for analyzing pygmy rabbit habitats. This image product was also used to develop and field-test spatially explicit models (e.g., mixed spatial regression models and hierarchical Bayesian models) depicting how vegetation cover, diet quality, and temperatures influence habitat use by pygmy rabbits. This represents a novel approach since it provides a multivariate, multi-scale empirical link between theoretical predictions of the effects and interactions of multiple environmental stressors on the functional responses by pygmy rabbits.
Although this imagery layer is just one input into a much larger GIS model, it represents data that has not previously been possible to attain. Use of UAS technology shows great promise in establishing new models that will aid in wildlife conservation.
Study Points of Contact:
Dr. Jennifer Forbey, Biology Professor
Boise State University
Jeff Sloan, Physical Scientist
USGS NUSO, Geosciences and Environmental Change Science Center
Sandhill Crane Population Estimates at the Monte Vista National Wildlife Refuge
In March 2011 the NUSO, in cooperation with the U.S. Fish and Wildlife Service (USFWS), performed its first UAS mission in civilian air space at the Monte Vista NWR in Colorado to study the feasibility of using UAS sensors to survey Sandhill cranes.
![Image of Sandhill cranes roosting site in the Monte Vista NWR taken from a UAS](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/media/images/uasCOSandhillCravengopr4601-8643017491.jpg?itok=5MrQfBQA)
The USFWS, mandated by Migratory Bird rules and regulation, is responsible for performing periodic surveys of the Sandhill crane population. Sandhill cranes are migratory birds that travel from Texas to Idaho (or as far as Siberia) annually and the Monte Vista NWR serves as a major stopover point during migration, making it a perfect location for conducting accurate population counts. These surveys are traditionally conducted by using fixed-wing aircraft, which can place both birds and staff at risk of mid-air collisions, or time-consuming ground-count methods, where biologists in the field attempt to visually enumerate the birds with sectional surveys. Although these methods produce the required information, they also introduce both safety and cost concerns, which made this a perfect choice for a UAS proof of concept mission.
As part of the planning process for this first UAS mission, NUSO had to establish and perform operational procedures to obtain FAA COA and radio spectrum approvals. The FAA COA process started on July 9, 2010, and the final approval was received six months later December 27, 2010. Specifications in the approved COA required that all Raven flights remain below 400 feet AGL, within visual line of sight of authorized trained observers and occur between morning civil twilight to evening civil twilight.
Determining if the Raven sensor could pick up the heat signature of the cranes in enough detail to allow biologists to obtain accurate counts was the main objective of this mission. But equally important was determining how the cranes would react to the Raven, especially since there were concerns that the cranes would see the Raven as an eagle, a major predator, and flush/fly away when it approached. To minimize any potential disruption to the cranes the plan was to fly the Raven at high altitudes or at night when the cranes were at roost. These plans had to be revised when the approved COA included both altitude and flight time limitations so also considering that most cranes depart the roost at or shortly after sunrise, flights were planned during the approximate 30-minute time frame between civil twilight and sunrise.
Safe completion of these initial flights clearly demonstrated that the Raven UAS could be flown without disruption to the cranes, and that the sensor payloads could identify their heat signatures. This left only the question of whether this data could be used to provide accurate population counts. In order to answer this final question population counts were first derived from the imagery captured by the Raven sensors. This was done by using mosaicking software to process the video into a single image of the complete roosting area. Next the easily identified heat signatures were counted and a Raven derived population count was established. This population count was then compared to a count established by the USFWS prior to the Raven mission during a ground-count to get an 'observed' population count, as well as to verify the location of the cranes within their roosting area. Results of this comparison between the ground based and UAS data derived population counts resulted in a 4.6% difference, which was determined to be acceptable.
These results established that utilizing UAS to perform population counts for Sandhill cranes is safe and produces accurate results. In fact, Dave Sharp, a retired USFWS biologist who has been working with the Sandhill cranes for over 25 years, said "I was skeptical about this process at first, but it has exceeded my wildest expectations". When asked if Raven video could be used to validate their counts, another biologist said that it was the other way around: his count will be used to validate the Raven's - "the Raven found birds that we did not know were there." The Refuge Manager, Floyd Truetken, said "I would like Raven and the team to come back to my refuge next year and they can come and train anytime. I would definitely recommend them to other refuge managers and biologists." There was 100% agreement among the scientists that this technology will revolutionize the way wildlife counts and tracking are conducted in the future.
Successful completion of this first mission also led to the NUSO being given approval from the FAA to perform night flights during later Raven missions performed in November 2011, March 2012, and March 2013. As a result of these additional missions, it was determined that Raven imagery provides acceptable population counts without disruption to the cranes, especially when flown at night when the cranes are at rest in the roosting areas.
Additional Information:
A Drone's-Eye View of Nature - New York Times
USGS Takes to the Sky - Earth Imaging Journal Article September/October 2011
Monitor Prescribed Wildfire Burns at Florida’s Eglin Airforce Base
![Remote pilot preparing to hand launch a fixed wing UAS during a prescribed wildfire burn in Florida](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/media/images/uasFLElginraven-8122752121.jpg?itok=FiYOpYKk)
In cooperation with the U.S. Forest Service, the NUSO conducted its first UAS flights in the United States during a prescribed burn at the Prescribed Fire Combustion and Atmospheric Dynamics Research Experiment (RxCADRE) event in February 2011.
Since this prescribed burn was at the Eglin Air Force Base in Florida all UAS operations occurred within military air space (versus civilian air space) which meant that no FAA or additional flight approvals were required. NUSO pilots successfully flew the Raven, one of the three UAS platforms flown, and demonstrated its ability to stream live thermal IR and natural color video to the fire command center to support fire management and operations.
Study Point of Contact:
Jeff Sloan, Physical Scientist
USGS NUSO, Geosciences and Environmental Change Science Center