CHART BOARD TO SELECT OBSERVATION OBJECTS ABOARD ORBITAL SPACECRAFT Russian patent published in 2008 - IPC G01C21/24 G09B29/00 

FIELD: space engineering.

SUBSTANCE: chart board designed for selecting observation objects aboard the orbital spacecraft comprises a semi-transparent plate depicting a curvilinear spacecraft trajectory, a flexible tape arranged behind the said plate with two copies of the Earth surface maps wherein the end points of equator of the first map are aligned with the start points of equator of the second map, and a device designed to move the tape with maps along the plate made up of two shafts spaced apart and linked up in parallel, the enclosed tape being arranged so as to move along equators of both maps. Note that, in compliance with this invention, the proposed chart board comprises additionally a flexible semi-transparent tape with two celestial maps, including ecliptic line, wherein the end points of equator of the first map are aligned with the start points of equator of the second map, and a device designed to move the tape with celestial maps along the plate made up of at least two spaced apart and linked up in parallel shafts whereon a new tape is located so as to move along the equators, second semi-transparent tape depicting curvilinear lines everyone being made in the scale of the celestial maps axes and being formed by the points spaced apart by an equal angular distance equal to half an opening of a planet disk visible from the spacecraft, and a device designed to move second plate relative to the first one along the axes perpendicular to the maps equators. Note that the scales of celestial maps and the width of the tapes with celestial maps are identical to the scales of the Earth surface maps and the tapes with the Earth surface maps and that both maps scales equatorial axes are represented at the ration of 1:K where K is the factor of compliance of the scales of equatorial scales defined from the formula K=1-tω/(2π+Δ Ω), where T is the spacecraft period, ω is the Earth angular speed of revolution in inertial space, Δ Ω is the helical orbit precession in the inertial coordinate system. Note here that the width of the second plate complies with that of the first plate, the former being determined from the formula L = arccos([cosQ-sin ε sin i]/[cos ε cos i])L_s/2π, where L_s is the length of equatorial scale of one celestial map, Q is the angle of half-opening of planet disk visible aboard the spacecraft, ε, i are the angles of inclination of the planes of ecliptic and spacecraft orbit to the equator plane, respectively.

EFFECT: expanded performances of chart board.

8 dwg