ALBERT

Description: The Airborne Infrared Disaster Assessment System (AIRDAS) is a four-channel scanner designed and built at NASA-Ames for the specific task of supporting research and applications on fire impacts on terrestrial and atmospheric processes and also of serving as a vital instrument in the assessment of natural and man-induced disasters. The system has been flown on numerous airframes including the Navajo, King-Air, C0130, and Lear Jet 310 and a 206. The system includes a configuration composed of a 386 PC computer workstation, a non-linear detector amplifier, a sixteen-bit digitizer, dichroic filters, and Exabyte 8500 5Gb Tape output, VHS tape output, a Rockwell GPS and a 2-axis gyro. The AIRDAS system collects digital data in four wavelength regions, which can be filtered: band 1 (0.61-0.68 microns), band 2 (1.57-1.7 microns), band 3 (3.6-5.5 microns), and band 4 (5.5-13.0 microns), an FOV of 108 degrees, an IFOV of 2.62 mrads, and a digitized swath width of 720 pixels. The inclusion of the non-linear detector amplifier allows for the accurate measurement of emitted temperature from fires and hot spots. Lab testing of the scanner has indicated temperature assessments of 800 C without detector saturation. This has advantages over previous systems which were designed for thermal measurement of earth background temperatures, and were ill-equipped for accurate determination of high intensity conditions. The scanner has been flown successfully on data collection missions since 1992 in the western US as well as Brazil. These and other research and applications responses will be presented along with an assessment of future directions with the system.a

Description: Visual and derivative analyses of AVIRIS spectral data can be used to detect algal accessory pigments in aquatic communities. This capability extends the use of remote sensing for the study of aquatic ecosystems by allowing detection of taxonomically significant pigment signatures which yield information about the type of algae present. Such information allows remote sensing-based assessment of aquatic ecosystem health, as in the detection of nuisance blooms of cyanobacteria or toxic blooms of dinoflagellates. Remote sensing of aquatic systems has traditionally focused on quantification of chlorophyll a, a photoreactive (and light-harvesting) pigment which is common to all algae as well as cyanobacteria (bluegreen algae). Due to the ubiquitousness of this pigment within algae, chl a is routinely measured to estimate algal biomass both during ground-truthing and using various airborne or satellite based sensors, including AVIRIS. Within the remote sensing and aquatic sciences communities, ongoing research has been performed to detect algal accessory pigments for assessment of algal population composition. This research is based on the fact that many algal accessory pigments are taxonomically significant, and all are spectrally unique. Aquatic scientists have been refining pigment analysis techniques, primarily high performance liquid chromatography, or HPLC, to detect specific pigments as a time-saving alternative to individual algal cell identifications and counts. Remote sensing scientists are investigating the use of pigment signatures to construct pigment libraries analogous to mineral spectral libraries used in geological remote sensing applications. The accessory pigment approach has been used successfully in remote sensing using data from the Thematic Mapper, low-altitude, multiple channel scanners, field spectroradiometers and the AVIRIS hyperspectral scanner. Due to spectral and spatial resolution capabilities, AVIRIS is the sensor of choice for such studies. We present here our results on detection of algal accessory pigments using AVIRIS data.