| US 7,548,187 B1 | ||
| Adaptive clutter filtering to improve high sub-clutter visibility radar detection performance | ||
| Gregory S. Laste, Hudson, N.H. (US); and Garret E. Murdza, Nashua, N.H. (US) | ||
| Assigned to BAE Systems Information and Electronic Systems Integration Inc., Nashua, N.H. (US) | ||
| Filed on Nov. 08, 2006, as Appl. No. 11/594,419. | ||
| Claims priority of provisional application 60/734902, filed on Nov. 09, 2005. | ||
| Int. Cl. G01S 13/00 (2006.01); G01S 13/50 (2006.01) | ||
| U.S. Cl. 342—159 [342/104; 342/109; 342/195] | 18 Claims |
| 1. In an aircraft-mounted active radar for detecting incoming threats, a method for adaptively setting the clutter line of
a filter used to reject clutter to correspond to the Doppler shift associated with sensed aircraft ground speed, comprising
the steps of:
analog-to-digitally converting radar pulses received at the aircraft from a surveilled area;
range gating the returned pulses;
multiplying a predetermined number of pulses from a range gate with weights;
applying the pulse weights to a fast Fourier transform to generate side-by-side Doppler cells; and,
selecting those Doppler cells for activation having Doppler shift frequencies above a clutter line Doppler shift frequency
associated with the sensed aircraft ground speed, thereby to reject clutter having Doppler shifts below the aircraft ground
speed and for passing returns having Doppler shift frequencies above the aircraft ground speed, whereby the clutter rejection
line is set in accordance with the sensed aircraft ground speed.
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