ISAR imaging radar system

DETAILED DESCRIPTION In accordance with the present invention, an improved ISAR radar method and system is provided that enhances doppler resolution by using a computational method that eliminates from the received ISAR signals the effects of range migration that cause doppler smearing.
According to one aspect of the present invention, there is provided a method for improving ISAR image processing by eliminating range migration effects from a moving object.
The method of the present invention comprises the steps of first generating an inverse synthetic aperture radar (ISAR) image for zero doppler range cells.
The method performs this step by averaging the IQ data for each range bin over all pulses from the sensor.
Next, the method includes the step of compensating each of the data points by a factor representing the effect of non-zero doppler frequency shifts in the data points.
The method further includes forming the ISAR image by applying the doppler filter to the compensated datapoints.
The method and system of the present invention embodies a computational procedure that properly computes the range/doppler image for constant velocity targets.
Compared with the known ISAR doppler processing methods, the present invention avoids the generation of spurious ISAR images.
The result is a higher resolution range and doppler image of moving targets.