GeoSAR: New IFSAR Technology for High Definition Mapping
GeoSAR is a one-of-a-kind remote sensing system that has helped IFSAR emerge as an important remote sensing technology. It is the worlds only dual-band (X and P), dual sided, dual polarimetric, single pass IFSAR sensor. It succeeds in mapping below canopies (by means of the P-band), imaging with a high degree of accuracy through perennially cloud covered areas. It also demonstrates an ability to penetrate dry soils, which could reveal buried evidence of ancient civilizations or sub-surface features. GeoSAR reveals subtle aspects of the terrain ranging from the dielectric properties of soils to biomass to terrain categorization. It is used to update aging topographic maps with elevation models and to extract planimetric features for GIS databases. GeoSAR also integrates a lidar profiler that measures elevation along a nadir line below the aircraft. This profile data is used to improve the geometric integrity of radar product mosaics and validates the height accuracies of the X and P band data.
GeoSAR is mounted on a Gulfstream II aircraft and acquires data at flight altitudes up to 40,000 feet over terrain. There are two X band and two P band antennas on each side of the aircraft. Each antenna is side looking, thereby producing overlapping 12km swaths in X and P off both sides of the aircraft. This enables single pass interferometry for simultaneous acquisition of all X and P swaths in one pass of the aircraft. Given its airspeed, GeoSAR acquires IFSAR data at the rate of 24,000 square kilometers per hour; an unsurpassed benchmark for airborne SAR mapping.
The intensity or magnitude images show ground features such as roads, trails, buildings, forest stands, water bodies and drainages, agricultural features, and other signs of human and natural impacts to the earth.