BOREAS Aircraft Data Processing

Gary Angelici, Lidia Popovici, Steve Klooster

BOREAS (BOReal Ecosystem Atmosphere Study) is an international, interdisciplinary scientific study which has the goal of improving our understanding of the interactions between the boreal forest biome and the atmosphere in order to clarify their roles in global change. Hundreds of investigators and staff are involved in deploying a wide range of sophisticated instruments and aircraft in the boreal forest of Canada during several twenty day periods in 1993 and 1994. While selected investigators in the Earth System Science Division are performing research with BOREAS, this effort involves the generation of several high precision data products from the imagery returned by the MAS (MODIS Airborne Simulator) and NS001 sensors flying on NASA's C-130.

NS001 image data received from several aircraft overflights of BOREAS study areas will be screened for problems and logged. Navigational data will be applied to geometrically correct the aircraft imagery, which is distorted due to various aircraft perturbations such as pitch and roll, to register with a map base. Optical thickness data and atmospheric radiance models will be applied to atmospherically-correct visible and near infrared channels of both NS001 and MAS data. In addition to image products, corrected reflectance and temperature statistics will be generated from these calculations. These numbers will be loaded into the BORIS (BOREAS Information System) and applied by BOREAS scientists in ecosystem models and in various research investigations. After the project, the images and statistics will be published on CD-ROM by BORIS staff for use by investigators and others for years to come.

In 1994, software to geometrically- and atmospherically- correct the data and create EOS (Earth Observing System) Level 2 data products was written and has undergone testing. Atmospheric models, such as Modtran and 6S, were applied to BOREAS radiosonde, sunphotometer, and other data to derive parameters necessary to atmospherically-correct both visible and thermal channels of the sensors. The intent of this work is to create the first software system capable of, in a single execution, making large quantities of geometrically-distorted and atmospherically-uncorrected aircraft data useful for not only scientific studies such as BOREAS, but also for GIS (geographic information system) applications which can utilize the remotely-sensed information provided by aircraft sensors.

Ames-Moffett contact: Gary Angelici

gangelici@gaia.arc.nasa.gov

or tel: (415) 604-5947

Headquarters program office: OSSA