Centroid seeking method for determining azimuth and elevation angle simultaneously

Claim 2

A target angle resolution system comprising: radar transmitting and receiving means alternately and directionally transmitting pulse energy and directionally receiving available reflected energy signals, said alternate transmission and reception occuring a plurality of times during a movement by said radar means of successive transmissions through a scan angle with respect to said radar means in any desirable plane, each pulse transmission being preceded by a short period of absence of transmission and reception activity; means coupled to said transmitting and receiving means for eliminating insignificant reflected energy signals and producing separate outputs representative of significant reflected energy signals received during successive pulses, said means for eliminating and producing comprising coupling circuitry, a threshold circuit connected to said coupling circuitry, and a pulse producing circuit coupled to said threshold circuit, said coupling circuitry comprising bandpass filter means, and switching means coupled between said bandpass filter means and said threshold circuit; and a digital computer coupled to said means for eliminating and producing, to count said separate outputs produced during movement of said transmissions through a dwell angle portion of said scan angle during which movement significant reflected energy is received, and to produce information representing the center of said dwell angle.

Claim 3

A target angle resolution system comprising: pulse Doppler radar transmitting and receiving means alternately and directionally transmitting pulse energy and directionally receiving available reflected energy signals, said alternate transmission and reception occurring a plurality of times during a movement by said radar means of successive transmissions through a scan angle with respect to said radar means in any desirable plane, each pulse transmission being preceded by a short period of absence of transmission and reception activity; means coupled to sAid transmitting and receiving means for eliminating insignificant reflected energy signals and producing separate outputs representative of significant reflected energy signals received during successive pulses, said means for eliminating and producing comprising coupling circuitry, a threshold circuit connected to said coupling circuitry, and a pulse producing circuit coupled to said threshold circuit, said coupling circuitry comprising signal acceptance and storage means, and switching means coupled between said signal acceptance and storage means and said threshold circuit, said signal acceptance and storage means including a bank of separate bandpass filters, each filter having a different pass band from the others, and a storage circuit coupled to each filter, and said switching means being a sequentially scanning switch for scanning separately the storage circuits; and a digital computer coupled to said means for eliminating and producing, to count said separate outputs produced during movement of said transmissions through a dwell angle portion of said scan angle during which movement significant reflected energy is received, and to produce information representing the center of said dwell angle.

Claim 4

A target angle resolution system comprising: pulse Doppler radar transmitting and receiving means alternately and directionally transmitting pulse energy and directionally receiving available reflected energy signals, said alternate transmission and reception occurring a plurality of times during a movement by said radar means of successive transmissions through a scan angle with respect to said radar means in any desirable plane, each pulse transmission being preceded by a short period of absence of transmission and reception activity; means coupled to sAid transmitting and receiving means for eliminating insignificant reflected energy signals and producing separate outputs representative of significant reflected energy signals received during successive pulses, said means for eliminating and producing comprising coupling circuitry, a threshold circuit connected to said coupling circuitry, and a pulse producing circuit coupled to said threshold circuit, said coupling circuitry comprising signal acceptance and storage means, and switching means coupled between said signal acceptance and storage means and said threshold circuit, said signal acceptance and storage means including a bank of separate bandpass filters, each filter having a different pass band from the others, and a storage circuit coupled to each filter, and said switching means being a sequentially scanning switch for scanning separately the storage circuits; and a digital computer coupled to said means for eliminating and producing, to count said separate outputs produced during movement of said transmissions through a dwell angle portion of said scan angle during which movement significant reflected energy is received, and to produce information representing the center of said dwell angle.

Claim 5

The resolution system of claim 2 wherein the movement by said radar means of the successive transmissions is through scan angles in azimuth planes and in elevation planes and the information produced in said scans represents the angle co-ordinates in azimuth and elevation of a reflector of significant reflected energy signals.

Claim 6

A target angle resolution means comprising: pulse Doppler radar transmitting and receiving means alternately transmitting partially overlapping lobes of energy pulses and receiving reflected energy signals available from each of said lobes, said transmitting and receiving means including receiving channels separate from each other, each of said channels being capable of receiving energy from a different one of said lobes, said alternate transmission and reception being accomplished a plurality of times by said transmitting and receiving means while antenna means within said transmitting and receiving means and coupled to said channels moves said lobes through a scan angle in azimuth and produces said overlapping lobes each having one axis in a vertical plane containing the axis of the other, each of the times of said plurality being separated by a time of absence of transmission and reception; means for selecting including banks of bandpass filters coupled to each of said channels, for selecting significant reflected energy signals and producing output pulses representative of the reception thereof; and a digital computer coupled to said means for selecting, to count output pulses from each of said channels, and to produce information representative of the center of the portion of said scan angle in which significant signals are reflected from said lobes, which of said lobes contains the origin of stronger reflected energy signals, and where within said lobe said origin is located, said information representative of the center of the portion of said scan angle indicating the angle co-ordinate in azimuth of the said origin and the said information representative of the lobe location of said origin indicating the angle co-ordinate in elevation of said origin.

Claim 7

A target angle resolution means comprising: pulse Doppler radar transmitting and receiving means alternately transmitting partially overlapping lobes of energy pulses and receiving reflected energy signals available from each of said lobes, said transmitting and receiving means including receiving channels separate from each other, each of said channels being capable of receiving energy from a different one of said lobes, said alternate transmission and reception being accomplished a plurality of times by said transmitting and receiving means while antenna means within said transmitting and receiving means and coupled to said channels moves said lobes through a scan angle in azimuth and produces said overlapping lobes each having one axis in a vertical plane containing the axis of the other, each of the times of said plurality being separated by a time of absence of transmission and reception; means for selecting including banks of bandpass filters coupled to each of said channels, for selecting significant reflected energy signals and producing output pulses representative of the reception thereof; and a digital computer coupled to said means for selecting, to count output pulses from each of said channels, and to produce information representative of the center of the portion of said scan angle in which significant signals are reflected from said lobes, which of said lobes contains the origin of stronger reflected energy signals, and where within said lobe said origin is located, said information representative of the center of the portion of said scan angle indicating the angle co-ordinate in azimuth of the said origin and the said information representative of the lobe location of said origin indicating the angle co-ordinate in elevation of said origin.