Patent ID: 8134492

Claim:
A method for searching an angular region of a radar search volume about a given cued direction and with a maximum range, where the search of the radar search volume is performed with sequentially applied radar beams having defined beamwidths, said method comprising the steps of: acquiring error information; from said error information, determining azimuth and elevation extents of a search face of the radar search volume about the cue direction; determining an angular extent of each of a plurality of radar beams in azimuth and elevation; from said angular extents in azimuth and elevation for each radar beam, determining a number of beams required to cover the search face of the radar search volume; determining a dwell time for each of the radar beams given the maximum range; taking a product of said number of beams multiplied by the dwell time per beam to obtain a search time; comparing said search time with a maximum allowable search time; initiating radar scanning over said search face with said number of beams if said search time is less that said maximum allowable search time; and partitioning said search face into sub-search-faces if said search time is greater than said maximum allowable search time, and for each of said sub-search-faces, initiating radar scanning; wherein said step of determining the number of beams required to cover the search face includes the calculation of N = [ 1 + 2 ⁢ ⁢ flr ⁢ ⁢ ( ( A ext 2 ⁢ Δ ⁢ ⁢ A ) + ( 1 2 ) ) ] ⁡ [ 1 + 2 ⁢ ⁢ flr ⁢ ⁢ ( ( E ext 2 ⁢ Δ ⁢ ⁢ E ) + ( 1 2 ) ) ] + 4 ⁡ [ 1 + flr ⁢ ⁢ ( A ext 2 ⁢ Δ ⁢ ⁢ A ) ] ⁡ [ 1 + flr ⁢ ⁢ ( E ext 2 ⁢ Δ ⁢ ⁢ E ) ] where: A ext is half the azimuth extent of the search face; E ext is half the elevation extent of the search face; ΔA is the azimuthal beam separation at constant elevation; ΔA=(β/2)cos α, where β is the beam width and α is equal to ½ the acute angle of the two lines that extend from the center of a radar beam to the points of intersection of the circumference of the beam with the circumference of an adjacent beam; ΔE is the elevation separation of the line of centers of the horizontal rows; ΔE=(β/2)(1+sin α); and flr is a floor function that truncates the argument to the highest integer less than the argument.