Electro-optical ranging apparatus having scanning circuitry and servoloop processor for resolving separation of images on photoelectric detector arrays

US4589770A · kind A · utility

Assignee

• The Boeing Company · US

Inventors

• Philip Jones · Roma, IT
• William R. Jones · Kent, US
• Moorfield Storey, Jr. · Seattle, US

Key dates

• Filing date: Oct 25, 1982
• Grant date: May 20, 1986
• Expiry date: Oct 25, 2002

Classification

• Technology area (CPC G): Physics
• CPC primary: G01S11/12
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

In an optical ranging apparatus, especially designed for measuring the range to a source of infrared radiation, a narrow band time-shift servoloop processor is used to resolve the offset (separation distance) of images of the infrared source that are projected onto first and second, juxtaposed photooptical detector arrays. The range (distance) to the infrared source is functionally related to the measured offset of the infrared images. To enable the servoloop processor to measure this offset, the outputs of the first and second detector arrays are automatically scanned by electronic scanning circuitry to develop first and second time-variable signals that represent the relative positions of the infrared images on the respective arrays. These time-variable signals are substantially overlapping, and the slight phase or time separation between these signals is related to the offset of the images on the detector arrays. The servoloop processor receives the substantially overlapping time-variable signals from the scanning circuitry and resolves the time difference therebetween as a continuously variable time shift .DELTA.t signal. The measured offset is then fed to a ranging processor t…