Compression network displaced phase center electronic correlator

A synthetic array processing system responsive to doppler history signals each representative of points on a surface comprising:

• signal forming means for developing a plurality of doppler history signals having time relations representative of the position of points on the surface and each having substantially the same center frequency, wherein said signal forming means includes:
• (i) coherent radar means for transmitting energy to a remote surface and for developing doppler traces representative of positions of objects on said remote surface,
• (ii) recording means responsive to said radar means for recording said doppler traces in range and azimuth on a storage surface, and
• (iii) scanning means coupled to said recording means for scanning said storage surface in azimuth at predetermined range positions to develop a plurality of doppler history signals at each range position;
• heterodyning means responsive to said doppler history signals to vary the center frequency thereof as a function of time;
• dispersive delay means coupled to said heterodyning means for developing a pulse from each doppler history signal, said pulses having a time relation as a function of the center frequency of said doppler history signals;
• utilization means, including a utilization scanning circuit, coupled to said dispersive delay means and to said scanning means for time relating the pulses in range and azimuth;
• an azimuth sweep generator coupled to said scanning means for controlling the length of azimuth scan of said scanning means as a function of the square root of range;
• an offset mixing means coupled between said scanning means and said heterodyning means and responsive to said azimuth sweep generator for varying the center frequency of said doppler history signals as a function of the square root of range;
• and
• means coupling said azimuth sweep generator to said utilization scanning circuit of said utilization means to control the length of azimuth scan thereof as a function of the square root of range.

A synthetic array processing system responsive to doppler history signals each representative of the azimuth and range of points over a range and azimuth interval of a remote surface comprising

• first means for storing said doppler history signals on a storage surface in range and in azimuth,
• second means responsive to said first means for developing a plurality of the doppler history signals during each of a plurality of azimuth time periods of scanning along said storage surface, said azimuth time periods being repetitive over a range interval of said storage surface, each of said doppler history signals having a time relation representative of the position of a different point on the surface, each having a time versus frequency slope, and each having substantially the same center frequency,
• mixing means responsive to said doppler history signals to vary the center frequency thereof as a function of time during each azimuth time period and to develop a predetermined time versus frequency slope,
• ultrasonic dispersive delay means coupled to said mixing means and having a time versus frequency characteristic that is the conjugate of said predetermined time versus frequency slope for developing pulses having a time relation as a function of the center frequency of said doppler history signals provided by said mixing means,
• and mapping means coupled to said second means and to said dispersive delay means for relating the pulses in time during each azimuth time period over the range interval.