Ppi display system with deflection modulation to reduce spoking

Claim 3

Apparatus for reducing spoking caused by discrete scanning lines on a PPI display, comprising: a. means for continuously laterally deflecting each said scanning line in a random manner throughout the gaps between the lines; and b. means for time integrating said modulated scanning lines, said integration producing a display in which the appearance of spokes is substantially reduced.

Claim 4

Apparatus for reducing spoking caused by discrete scanning lines on a PPI display, comprising: a. means for continuously laterally deflecting each said scanning line in a random manner throughout the gaps between the lines; and b. means for time integrating said modulated scanning lines, said integration producing a display in which the appearance of spokes is substantially reduced.

Claim 5

In a PPI display sstem having a display representing slant range and azimuth angle corresponding to a discrete number of beam positions, apparatus comprising: a. scanning signal generator means for generating scanning signals; b. a modulation circuit for continuously and randomly modulating said scanning signals; and c. high persistence display means, driven by said modulated scanning signals, said modulated scanning signal causing lateral deflection of the discrete representations on said display means such that each line of the display is widened so as to fill the gaps between the lines, and the high persistence feature of said display means providing time integration of said latEral deflections, so as to reduce the effect of spoking on the display.

Claim 6

In a PPI display sstem having a display representing slant range and azimuth angle corresponding to a discrete number of beam positions, apparatus comprising: a. scanning signal generator means for generating scanning signals; b. a modulation circuit for continuously and randomly modulating said scanning signals; and c. high persistence display means, driven by said modulated scanning signals, said modulated scanning signal causing lateral deflection of the discrete representations on said display means such that each line of the display is widened so as to fill the gaps between the lines, and the high persistence feature of said display means providing time integration of said latEral deflections, so as to reduce the effect of spoking on the display.

Claim 7

In a PPI display system having a display representing slant range and azimuth angle corresponding to a discrete number of beam positions, apparatus comprising: a. scanning signal generator means for generating scanning signals, said scanning signal generator means comprising a scan sawtooth generator, a noise generator, and an adding circuit for combining the outputs of said scan sawtooth generator and said noise generator to produce modulated scanning signals; b. a range sawtooth generator for providing range signals; c. converting means for converting said range signals and said modulated scanning signals to provide orthogonal drive signals; and d. high persistence display means, driven by said orthogonal drive signals, said high persistence display means providing time integration of the display, so as to reduce the effect of spoking on the display.

Claim 8

In a PPI display system having a display representing slant range and azimuth angle corresponding to a discrete number of beam positions, apparatus comprising: a. scanning signal generator means for generating scanning signals, said scanning signal generator means comprising a scan sawtooth generator, a noise generator, and an adding circuit for combining the outputs of said scan sawtooth generator and said noise generator to produce modulated scanning signals; b. a range sawtooth generator for providing range signals; c. converting means for converting said range signals and said modulated scanning signals to provide orthogonal drive signals; and d. high persistence display means, driven by said orthogonal drive signals, said high persistence display means providing time integration of the display, so as to reduce the effect of spoking on the display.

Claim 9

The apparatus as described in claim 4 wherein said display means is a long persistence CRT.

Claim 10

The apparatus as described in claim 5 comprising a scan generator centering control circuit, and wherein the output of said noise generator is coupled to the output of said centering control.

Claim 13

The method as described in claim 7, wherein said modulating signal is generated by a noise generator.

Claim 16

The method as described in claim 9, wherein each scan line is laterally deflected at a frequency greater than the radar bandwidth.

Claim 17

Apparatus for reducing spoking on a PPI display for a radar system, comprising means for laterally deflecting each scanning line on said display in a manner such that each such line is sperad out angularly to fill the gaps between the lines, said laterally deflecting means providing that each scan line is continuously and randomly laterally deflected as it is scanned.

Claim 18

Apparatus for reducing spoking on a PPI display for a radar system, comprising means for laterally deflecting each scanning line on said display in a manner such that each such line is sperad out angularly to fill the gaps between the lines, said laterally deflecting means providing that each scan line is continuously and randomly laterally deflected as it is scanned.

Claim 19

The apparatus as described in claim 11, wherein said deflecting means deflects said lines at a frequency greater than the radar bandwidth.

Claim 20

The apparatus as described in claim 12, wherein said deflecting means comprises a wideband noise generator.