초록 ▼

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 photo

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 D

대표청구항 ▼

An electro-optical apparatus for measuring the range R to a distant source of light, comprising: first and second optical/detector assemblies, each of which comprises optics having an optical axis, a field of view FOV and frame length lf, and an array of photoelectric detector elements arranged at a

An electro-optical apparatus for measuring the range R to a distant source of light, comprising: first and second optical/detector assemblies, each of which comprises optics having an optical axis, a field of view FOV and frame length lf, and an array of photoelectric detector elements arranged at a center-to-center distance ld along a predetermined scanning direction on a focal plane normal to said optical axis and upon which an image of said source is focused by said optics, said first and second assemblies being arranged with said optical axes parallel and spaced apart by a predetermined distance d along a baseline that in turn defines a perpendicular bisector, said assemblies adapted for being oriented so that said perpendicular bisector defined by said baseline points generally in the direction of a distant source of light such that images of the source are focused by said optics on said arrays at relatively different positions with respect to corresponding points on said arrays wherein such difference in the image positions is defined by an image offset Dtt1 representing the image position on said array of said first optical/detector assembly and so as to produce, in concert therewith, a second time/amplitude-varying signal t2 representing the image position on said array of said second optical/detector assembly wherein said signals t1 and t2 exhibit a phase difference referred to as time-shift DD1 and t2 from said scanning circuitry means and having an output at which a signal is produced representing said time shift D1 and t2, said servoloop processor comprising the subcombination of: variable delay means connected to a first input of said processor for variably delaying that one of said input signals t1 and t2 that leads the other input signal; difference-taking means for receiving the variably delayed signal from said variable delay and the trailing signal from a second input to said processor for producing an error signal corresponding to the phase difference therebetween; differentiator means connected to said second input of said processor for differentiating the signal thereat to produce a reference signal having substantially the same phase as said error signal; multiplier means connected to said difference-taking means and to said differentiator for multiplying said error signal with said reference signal to produce a correction signal; integrator means connected to said multiplier means for receiving and integrating said correction signal, said integrator means having an output producing an integrated correction signal that is connected to said variable delay means for controlling the amount of delay produced thereby; and said output of said processor connected to said output of said integrator means for providing at said processor output said time-shift signal DDDR=(lft/(FOV) Dt ld).