GB1167671A - Improvements in Pulse Radar - Google Patents

Abstract

1,167,671. Pulse radar. HUGHES AIRCRAFT CO. 20 Feb., 1968, No. 8283/68. Heading H4D. In a pulse radar with range sweeps effected sequentially in elevation at each azimuth position, the video returns for each range interval in each range sweep are amplitudequantized and the quantized signals are correlated over several elevations to provide a target detection signal. In the embodiment the video amplitude quantization covers eight steps which are three-bit coded and "hits are enumerated as e.g. 7-hit and the acceptable hit patterns are as shown in Fig. 3 where each three-by-three matrix (" window ") represents adjacent azimuth (columns) and elevation (rows) positions for a particular range interval (see also Fig. 2), a moving window technique is incorporated. Detailed embodiment. Figs. 2, 4.-In the embodiment there are ten range sweeps sequentially in elevation and each range sweep has 400 range intervals. A memory 25, Fig. 4, has a capacity of 4000 words each of eighteen bits and the capacity of a memory 30 is 400 words of six bits (one word for each of the 400 range intervals of a range sweep); for each of the 4000 range intervals in each azimuth position memory 25 contains the three-bit codes corresponding to same range interval in six of the nine positions of the three-by-three matrix. Memories 25, 30 are addressed utilizing counters 34, 35, as shown. When the coded signal for range " bin " C1, Fig. 2 (selected range interval R x ) of azimuth Z 1 and elevation E c is supplied to register 32, memory 25 supplies for temporary storage to read register 25a three-bit the codes representing the video in related range bins in previous azimuths Z 2 , Z 3 at elevations E c , E B and E A . Memory 30 simultaneously transfers the three-bit codes representing the video in range bins at B1 and A1 to register 30a. Thus the three-bit codes for all positions of the three-by-three matrix ("window ") 20 are available simultaneously and at the same time as the arrival of the three-bit code at position Cl. A detector 50 determines whether any of the acceptable hit patterns is present in the matrix for each range bin and comprises gating combinations, Figs. 5, 6, 7 (none shown).