This paper presents the first results on Section describes the SIR-C data acquisition scenario. Section 111 reviews the processing algorithm. Section IV presents SIR-C ScanSAR images. Additional applications of by the future missions arc addressed in the end of the II. SIR-C DATA ACQUISITION The SIR-C flight system consists of an antenna structure and electronics integrated into the Shuttle payload and digital electronics and high rate recorders located in the crew cabin. The SIR-C radar system employs a planar active phase array antenna. The antenna beam can steered over a range in elevation and over a range azimuth. The antenna panel was into the payload with a 14 tilt angle and space nominally flew with a 26 roll resulted in a 40 off-nadir look without any electronic steering. Key radar characteristics arc summarized in 1. More detailed description of t SIR-C system can found in . --3- was operate in a number of] adar modes with various frequency and polarization were digitized at a rate of 180 data high density digital and further ground data Numerous products have been and arc being produced for analysis Silt-C team as well as for distribution to the general public. the two space shuttle missions, most of the data were acquired using the continuous strip mode. Additionally, a fcw of were acquired using Scan spotlight and squint mode, l'able 2 the flights, which total up to onc hour worth of data. illustrate how radar parameters were up, Table 3 shows commanded radar for flight 2 82.1. This acquired an ascending pass over in Oklahoma on 5 of the second mission for a duration of 3 minutes and 24 seconds. It used the four-beam Scan SAR steering angles for these four were commanded --1 O.