PROCESS FOR SELECTION OF OBJECT AGAINST BACKGROUND OF STARS Russian patent published in 1998 - IPC

FIELD: passive optical location of remote object against background of stars. SUBSTANCE: process is based on reading of image of object and stars recorded in focal plane of telescope 1 by first scanning aperture in image recording unit 2, on processing of obtained videosignal , on subsequent isolation of object, on amplitude selection of videosignal in gating unit 3 in voltage interval between two reference levels and , on binary quantization in threshold processing unit 4, on digitization of selected videosignal in summing unit 5, on logic summing of N frames of selected videosignal and on isolating of object. Additional amplitude selection of videosignal with upper reference level is carried out, summary videosignal is converted to luminous flux Φ_h of summary image in converter 6, spatial frequency filtration of luminous flux in direction α = α_st± 90^° is conducted, filtered luminous flux is read in filtration unit 7, videosignal is obtained by second scanning aperture in unit of backward conversion. Two-level quantization with threshold V_b and discretization of obtained videosignal in dialysis unit 9 are performed. Coordinates of readings of non-zero digitized videosignal are found by line and frame, minimal τcmin

, τkmin and maximal τcmax, τkmax values of readings are determined by line and frame correspondingly, values τcmin, τcmax, τkmin, τkmax are analyzed, gating videosignal is formed by results of analysis, fragments of videosignal V_s in time interval corresponding to gate V_s are extracted. Minimal V_min and maximal V_max levels of videosignal of isolated fragment are recorded, reference levels and of signal are formed in compliance with V_min and V_max, angle α is found as . Object is isolated by excess of value V_b by results of analysis of values α_bck and α_st. Direction α_st coincides with that of images of stars in focal plane of telescope. EFFECT: increased noise immunity of process. 4 dwg