INSTANTANEOUS ACCURATE MEASUREMENT OF ORBIT OF SATELLITE BY VIRTUAL MODEL OF SMALL SKY

PROBLEM TO BE SOLVED: To attain measurement of a position of a satellite with high accuracy by a method in which states of an ionosphere and an atmospheric gas stratum surrounding the earth are expressed numerically by a change in a true value of the sum total of refractive indexes of a microwave. SOLUTION: States of an ionosphere and an atmospheric gas stratum surrounding the earth are various according to the time, seasons and places. These various states are expressed numerically on the basis of a notion of a change in a true value of the sum total of refractive indexes of a microwave. Concretely, two points of observation are provided on the ground and the microwave from a satellite flying through the sky is received thereat. The number of the microwaves measured at a prescribed time interval at the two points of observation is expressed by a linear equation in which an absolute value of a difference in the time of propagation of the microwave to the two points is made a variable. Besides, an angle formed by the direction of inrush of the microwave to one of the points of observation and a straight line connecting the two points is expressed by a linear equation in which the time of propagation to the other of the points of observation is made a variable. By this method, an actual position of the satellite is measured and an orbit is determined.