Method for improving SAR system sensitivity in the presence of RF interference
AssigneeERIM International, Inc.
InventorsRon S. Goodman, Ronald A. Schneider
Life of this patent
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Abstract
The sensitivity of a synthetic aperture radar (SAR) system employing stretch processing is improved in the presence of radio-frequency interference (RFI). The sequence of data processing operations initially uses a high number of bits to digitize radar echoes plus RFI, then uses floating-point arithmetic to perform range deskewing to "compress" RFI tones, followed by threshholding and nulling the primary RFI contributors, and finally re-quantizes the resulting radar signal to a lower number of bits and appropriately allocating these bits over the range of signal levels.
Claims6
A method of improving the sensitivity of a synthetic aperture radar (SAR) system, comprising the steps of:
- receiving a digital SAR signal exhibiting b1 bits per sample;
- range deskewing and threshold nulling the signal using floating-point arithmetic;
- and
- re-quantizing the signal using a number of bits per sample which is less than b1.
In a synthetic aperture radar (SAR) system, the method of improving sensitivity in the presence of radio-frequency interference, comprising the steps of:
- receiving a dechirped analog SAR signal
- performing an analog-to-digital conversion of the dechirped analog SAR signal utilizing b.sub.1 bits per sample to yield a plurality of digitized signal samples;
- converting the digitized signal samples into floating point data;
- range deskewing the floating point data;
- nulling the floating point data on a per-sample basis using an intensity value greater than a threshold value;
- and
- re-quantizing the result of the above steps utilizing a number of bits per sample which is lower than b.sub.1.
Dependencies are inferred from the claim text.