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NUPO 2013 Research Missions


Waterfowl and Habitat Surveys

Ruby Lake National Wildlife Refuge in Nevada
Zoomed into a Canon SX260 image taken from a UAS to show Mallard Ducks
Zoomed into a Canon SX260 image taken from a UAS to show Mallard Ducks

The Ruby Lake National Wildlife Refuge is managed by the U.S. Fish and Wildlife Service (USFWS) and is located in the Great Basin region in Nevada. The refuge provides necessary habitats for thousands of nesting and migrating waterfowl. The area is made up of marsh, meadows, grasslands, shrub-steppe upland and is located in the high desert at an elevation of near 6,000 feet. The unique setting of a wetland in the high desert provide an area that is visited by over 220 species of birds and migratory waterfowl, which is the primary purpose of the refuge.

In November of 2013, the USGS in cooperation with the USFWS conducted proof-of-concept missions over the refuge in an attempt to conduct sample waterfowl population census counts and to see if individual species could be distinguished from the data collected from the low-altitude UAS. Additional investigations with the data for determining base map nesting areas and vegetative health (using color infrared) were secondary interests, but equally important information that would aid in overall refuge management.

The proof-of-concept mission consisted of collecting data at several different flight heights and with different cameras, including GoPro Hero 3 video, Canon SX230 natural color imagery at various zoom levels, and with the Canon SX260 color infrared camera.

The ability to capture data at a resolution at an approximate 100' altitude using a zoomed camera setting shows great potential in utilization for waterfowl census counts and specific species identification. The mission proved the first time that this was a possibility with this sUAS platform and use of an off-the-shelf camera. The ability to utilize sUAS for refuge biologist and managers is of great interest for future use to provide a much safer and cost-effective way of collecting low-altitude remotely sensed data.

Color-infrared image taken with the Canon SX230
Color-infrared image taken with the Canon SX230
Normalized Difference Vegetation Index (NDVI) generated from UAS acquired data
Normalized Difference Vegetation Index (NDVI) generated from UAS acquired data
Study Point of Contact:
Darrell Freeman, Wildlife Biologist
U.S. Fish & Wildlife Service Ruby Lake National Wildlife Refuge
darrell_freeman@fws.gov
Publication:
ENVIRONMENTAL REVIEWS AND CASE STUDIES: Applications of Unmanned Aircraft Systems (UAS) for Waterbird Surveys - Cambridge Journals (http://journals.cambridge.org), September 2015.

Map Emergent Sandbar Habitats

Central Platte River Valley in Nebraska
Canon SX230 image of the river valley taken by the THawk at 200 feet
Canon SX230 image of the river valley taken by the THawk at 200 feet

The Central Platte River Valley in Nebraska is an internationally significant staging area for migratory water birds of the Central Flyway supporting over half a million Sandhill cranes and several million other waterfowl that migrate annually. However, changes in water and land use have transformed the river channel, altered adjacent wet meadows, and the structure of riparian habitats bringing the sustainability of migratory and resident birds, and other biota into question. A primary concern for managers is determining how river flows influence heights of sandbars used by endangered or threatened nesting birds (interior least tern and piping plover). But, due to the dynamic nature of river flows, measuring sedimentation processes over fine temporal scales (days), at high spatial resolution (centimeters) over long river reaches (kilometers), using traditional methods to acquire the needed data is both challenging and costly.

To investigate more cost effective data acquisition options a sUAS mission was performed in the summer of 2013. The objective of this mission was to use the T-Hawk, equipped with a high-resolution digital camera (Canon PowerShot SX230), to map the spatial extent and elevation of emergent sandbars along two reaches of the Platte River.

Both of these areas, managed by the Platte River Recovery Program, are pilot sites for sediment augmentation projects to evaluate strategies to offset deficiencies in sediment supply caused by upstream water regulation infrastructure. The USGS is already monitoring the morphology and sedimentation at these sites by quantifying suspended sediment transport using a combination of ground surveying (GPS transects), traditional bed and suspended sediment sampling, and surrogate technologies (laser diffraction and acoustic backscatter). Another benefit from this ongoing work is the establishment of ground control that supports the generation of orthophotographs and digital elevation models of the emergent sandbars. These field sites are also in close proximity to USGS stream flow-gaging stations, making water surface elevation data available from the continuous monitoring. Conventional real-time kinematic (RTK) surveys will be used to compare and demonstrate the accuracy and efficiency of mapping emergent sandbars with a sUAS.

Platte River 3D model and orthophoto generated from the UAS acquired data
Platte River 3D model and orthophoto generated from the UAS acquired data
Platte River elevation model and profile measurements generated from UAS acquired data
Platte River elevation model and profile measurements generated from UAS acquired data

Most of the imagery acquired during the mission was collected with the Canon SX230 on-board the T-Hawk, flown at perpendicular transects at 200 feet and 400 feet AGL. This flight path proved to be very effective for collecting survey-grade data with horizontal and vertical accuracies measuring in the centimeter range. This level of accuracy in both vertical and horizontal measurements demonstrates that acquired data has great potential for many types of hydrologic monitoring.

These preliminary mission results have already demonstrated that the sUAS acquired data has great promise for supporting hydrography modeling and measuring for sediment movement and augmentation studies.

Study Point of Contact:
Paul Kinzel, Hydrologist
U.S. Geological Survey Geomorphology and Sediment Transport Laboratory
pjkinzel@usgs.gov

Identify Abandoned Materials

Mojave National Preserve in California
UAS acquired image showing Joshua trees (yellow dots) identified with feature extration
UAS acquired image showing Joshua trees (yellow dots) identified with feature extration

In March 2013, the USGS National Unmanned Project Office, in cooperation with the National Park Service Mojave National Preserve, flew proof of concept sUAS missions to locate and survey abandoned solid waste for historical assessment potential and cleanup. The primary objective was to determine if sUAS technology could provide cost-effective, high-resolution aerial imagery in this isolated part of southeastern San Bernardino County that could be used to provide a historical record, as well as aiding the difficult task of identifying abandoned materials, determining historical significance, and supporting cleanup. Freely available satellite imagery does not meet the current resolution requirements and accessing sites via unmaintained two-track roads hampers ground efforts.

The passage of the California Desert Protection Act (CDPA) in 1994 created the Mojave National Preserve and placed it under the management jurisdiction of the NPS. Prior to that time, the area had seen a series of land uses, including Native American life, mining, grazing, and, during the 1920s and 1930s, homesteading. Most of the homesteading was focused in Lanfair Valley, a fairly flat, broadly oval expanse of about 150 square miles (120,000 acres) of Joshua tree-creosote shrub habitat. Homesteading resulted in the conversion of much of the publicly owned valley to private ownership, but drought and hardship during the 1930s triggered the reverse migration of the homesteaders, whose land parcels were subsequently handed down through families, divided or sold. After this the land, if used at all, was generally used for camping or other recreational purposes and not always well maintained. By 1994 when the CDPA was passed, roughly half of Lanfair Valley was a patchwork of private and public land; most parcels were 40 acres or smaller, and many had accumulations of abandoned solid materials, some with historic value. The newly established CDPA dictated that private land within the newly created preserve boundary should be acquired, if willing sellers exist and acquisition funds are donated from private sources.

Today, one of the greatest land management needs on the 1.6 million acres in the Preserve is to identify the locations of abandoned non-historic material, much of which is in Lanfair Valley, evaluate its historic significance and determine if cleanup is required. Materials determined to be historic are generally left on-site, providing self-discovery and recreational opportunities for the 20 million people who live within a four-hour drive of the preserve.

Low altitude imagery was acquired over four different areas of approximately one square mile using a GoPro Hero 2 mounted on a Raven and a Canon SX260 camera mounted on the T-Hawk. Viewing the data during the flights demonstrated that it was very useful for identifying abandoned material in locations that would be very difficult to find from higher-altitudes, primarily in ditches or low valley areas.

This mission successfully demonstrated the sUAS's ability to function as a low altitude reconnaissance and monitoring tool. The image data acquired with the sUAS could be used, either in real-time or during post-processing, to provide coordinates for the location of identified materials. Having access to this coordinate information allows the inspectors to save time by easily navigating directly to the required inspection sites.

An unexpected benefit from this high-resolution imagery was its ability to distinguish various vegetation types, including Joshua trees. Image data with this level of resolution can be used with automated extraction techniques to create vegetation inventories, which would provide resource managers with reliable method for creating vegetation inventories.

Study Point of Contact:
Annie Kearns, Natural Resoursces Specialist
Mojave National Preserve
anne_kearns@nps.gov