Accession Number : ADD014235

Title :   Frequency Agile Synthetic Aperture Radar.

Descriptive Note : Patent, Filed 1 Feb 88, patented 25 Jul 89,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Wehner, Donald R

Report Date : 25 Jul 1989

Pagination or Media Count : 24

Abstract : A radar transmission, reception and signal processing system generates high resolution synthetic aperture radar ground maps from air or space platforms using waveforms in which frequency is changed pulse-to-pulse. The transmitted radar signal is comprised of a series N bursts with n pulses per burst wherein each of the pulsed is a fixed frequency step, delta f either above or below one or the other of the n pulses, i.e., the n pulses comprises an ordered set and further, preferably, wherein the set of n pulses is arranged in time as a random permutation of the ordered set. In each of the k sample gates for each burst the n complex samples of reflectivity are inverse Fourier transformed from frequency domain samples of reflectivity to synthetic range domain profiles to result in an array of aligned range profiles in each of k coarse range delay positions. Azimuth or cross-range processing is accomplished by thetic range cell with a suitable azimuth reference to result in a set of complex numbers that represent complex reflectivity maps of the earth's surface in that coarse range bin. Patents. (RRH)

Descriptors :   *MAPS, *PATENTS, *PULSES, *RADAR SIGNALS, *SIGNAL PROCESSING, AZIMUTH, CELLS, COMPLEX NUMBERS, DELAY, EARTH(PLANET), FOURIER ANALYSIS, FREQUENCY, INVERSION, PERMUTATIONS, PROFILES, RADAR TRANSMITTERS, REFLECTIVITY, SAMPLING, SPACECRAFT, SURFACES

Subject Categories : Active & Passive Radar Detection & Equipment
      Cartography and Aerial Photography

Distribution Statement : APPROVED FOR PUBLIC RELEASE