Target motion compensator

Claim 3

A system as recited in claim 1 wherein said means for generating (V Delta t) sin theta /R and theta Delta t includes first rate multiplier means to which said velocity data is applied for producing an output representative of V Delta t, second rate multiplier means to which said heading rate data is applied for producing and output representative of theta Delta t, first read only memory means to which said azimuth data is applied for producing and output representative of sin theta , divider means to which said sine theta output and said range data is applied for producing and output representative of sin theta /R, and said computing means including gate means to which said V Delta t output is applied as a gating signal, and said sin theta /R and theta Delta t signals are applied to produce outputs representative of (V Delta t) (sin theta /R) and theta Delta t.

Claim 4

A system as recited in claim 2 wherein said means for generating (V Delta t)(Cos theta ) comprises: second read only memory means to which said azimuth data is applied for producing an output representative of cos theta , gate means to which said cos theta output is applied, and means to apply said V Delta t output to said gate means as a gating signal to produce as an output representative of (V Delta t)(Cos theta ).

Claim 5

In a system wherein an aircraft has a scan converter which includes a circulating memory for storing target hit data including azimuth and range data, apparatus for compensating said target hit data for aircraft motion as it is circulated between the output and input of said memory comprising: means for deriving signals representative of the azimuth data of a target ( theta ) from the output of said circulating memory, means responsive to said azimuth data signals to provide signals representative of sin theta , means for deriving signals representative of the range data (R) of said target from the output of said circulating memory, means for dividing sin theta signals by said range data signals to produce signals representative of sin theta /R, means on said aircraft for providing signals representative of aircraft velocity (V) and heading rate ( theta ) data, and heading sign means responsive to said velocity representative signals for generating signals representative of velocity per unit of time (V Delta t), means for multiplying sin theta /R representative signals by the V Delta t representative signal to produce signals representative of (V Delta t) (sin theta /R), means responsive to said heading rate representative signals for generating signals representative of heading rate per unit of time theta Delta t, means responsive to said heading at sign and the signals representative of heading rate per unit of time theta Delta t for generating add subtract control signals, means responsive to said heAding sign for combining the (V Delta t) (sin theta /R) signals and the theta Delta t signals with the azimuth signals derived from memory to provide compensated azimuth signals, means for applying said compensated azimuth signals to the input of said memory, means responsive to said azimuth signals for generating signals representative of cosine of said azimuth, (cos theta ), means for multiplying said signals representative of cos theta with said signals representative of V Delta t to provide signals representative of (V Delta t) (cos theta ), means for subtracting said (V Delta t) (cos theta ) representative signals from said range signals to produce compensated range signals, and means for applying said compensated range signals to the input to said memory.

Claim 6

In a system wherein an aircraft has a scan converter which includes a circulating memory for storing target hit data including azimuth and range data, apparatus for compensating said target hit data for aircraft motion as it is circulated between the output and input of said memory comprising: means for deriving signals representative of the azimuth data of a target ( theta ) from the output of said circulating memory, means responsive to said azimuth data signals to provide signals representative of sin theta , means for deriving signals representative of the range data (R) of said target from the output of said circulating memory, means for dividing sin theta signals by said range data signals to produce signals representative of sin theta /R, means on said aircraft for providing signals representative of aircraft velocity (V) and heading rate ( theta ) data, and heading sign means responsive to said velocity representative signals for generating signals representative of velocity per unit of time (V Delta t), means for multiplying sin theta /R representative signals by the V Delta t representative signal to produce signals representative of (V Delta t) (sin theta /R), means responsive to said heading rate representative signals for generating signals representative of heading rate per unit of time theta Delta t, means responsive to said heading at sign and the signals representative of heading rate per unit of time theta Delta t for generating add subtract control signals, means responsive to said heAding sign for combining the (V Delta t) (sin theta /R) signals and the theta Delta t signals with the azimuth signals derived from memory to provide compensated azimuth signals, means for applying said compensated azimuth signals to the input of said memory, means responsive to said azimuth signals for generating signals representative of cosine of said azimuth, (cos theta ), means for multiplying said signals representative of cos theta with said signals representative of V Delta t to provide signals representative of (V Delta t) (cos theta ), means for subtracting said (V Delta t) (cos theta ) representative signals from said range signals to produce compensated range signals, and means for applying said compensated range signals to the input to said memory.

Claim 7

Apparatus as recited in claim 4 wherein said means responsive to said azimuth data signals to provide signals representative of sin theta is a read only memory: said means responsive to said velocity representative signals to generate signals representative of V Delta t is a first rate multiplier means, said means responsive to said leading rate representative signals to generate signals representative theta Delta t is a second rate multiplier, and said means responsive to said azimuth data signals to provide signals representative of cos theta is a second read only memory.