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Automatic Altitude Calibration

IP.com Disclosure Number: IPCOM000097941D
Original Publication Date: 1961-Oct-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Van Horn, JF: AUTHOR

Abstract

A radar range pulse is brought into coincidence with the leading edge of the first return of radar video signals. Coincidence is determined during each cycle of radar PRF. Appropriate signals control a digital servo system, which in turn controls the range pulse to achieve and maintain coincidence.

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Automatic Altitude Calibration

A radar range pulse is brought into coincidence with the leading edge of the first return of radar video signals. Coincidence is determined during each cycle of radar PRF. Appropriate signals control a digital servo system, which in turn controls the range pulse to achieve and maintain coincidence.

An expanded pulse is derived from the fall delay circuit at system trigger time. This resets the digital control servo amplifier latches and causes the servo to drive in the decrease range direction. This same expanded pulse, inverted, disables the AND in the video channel, thus, eliminating effects of radar main bang. If the leading edge of the video first returns occurs ahead of the range pulse, the decrease latch is set.

This disables the increase latch and the digital servo continues to drive in the decrease range direction. However, if the range pulse occurs first, the increase latch is set and the decrease latch is disabled, causing the servo to drive in the increase range direction.

Since the servo response is extremely slow in comparison with the frequency of input control signals, the servo integrates many cycles of the PRF in establishing a resultant change in the output range control. This serves to minimize oscillation about the null or coincidence condition.

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