The aerial photography inventoried by the Pilot Land Data System
(PLDS) at NASA AMES Research Center has been transferred to the USGS
EROS Data Center. The photos were obtained from cameras mounted on
high and medium altitude aircraft based at the NASA Ames Research
Center. Several cameras with varying focal lengths, lenses and film
formats are used, but the Wild RC-10 camera with a focal length of 152
millimeters and a 9 by 9 inch film format is most common. The positive
transparencies are typically used for ancillary ground checks in
conjunctions with digital processing for the same sites. The aircraft
flights, specifically requested by scientists performing approved
research, often simultaneously collect data using other sensors on
board (e.g. Thematic Mapper Simulators (TMS) and Thermal Infrared
Multispectral Scanners). High altitude color infrared photography is
used regularly by government agencies for such applications as crop
yield forecasting, timber inventory and defoliation assessment, water
resource management, land use surveys, water pollution monitoring, and
natural disaster assessment.

To order, specify the latitude and longitude of interest. You will then be
given a list of photos available for that location. In some cases, "flight
books" are available at EDC that describe the nature of the mission during
which the photos were taken and other attribute information. The customer
service personnel have access to these books for those photo sets for which
the books exist.

The Advanced Solid-state Array Spectroradiometer (ASAS) data collection contains data collected by the ASAS sensor flown aboard NASA aircraft. A fundamental use of ASAS data is to characterize and understand the directional variability in solar energy scattered by various land surface cover types (e.g.,crops, forests, prairie grass, snow, or bare soil). The sensor's Bidirectional Reflectance Distribution Function determines the variation in the reflectance of a surface as a function of both the view zenith angle and solar illumination angle.

The ASAS sensor is a hyperspectral, multiangle, airborne remote sensing instrument maintained and operated by the Laboratory for Terrestrial Physics at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The ASAS instrument is mounted on the underside of either NASA C-130 or NASA P-3 aircraft and is capable of off-nadir pointing from approximately 70 degrees forward to 55 degrees aft along the direction of flight. The aircraft is flown at an altitude of 5000 - 6000 meters (approximately 16,000 - 20,000 ft.).

Data in the ASAS collection primarily cover areas over the continental United States, but some ASAS data are also available over areas in Canada and western Africa. The ASAS data were collected between 1988 and 1994.