local geodethic frame of reference
At calculations of the process of a laser ranging it is usually considered that a retroreflector wich is moving together with spacecraft, reflects the light pulses in directions directly opposite to the directions on which they come to it. However this statement is right only for the reflection process supervision in the frame of references in which the retroreflector is based at rest. But the spaceraft usually moves on an orbit.
The attempts to deduce the formulas describing laws of the beams reflection for the laser ranging of the spacecraft which is in an orbit, were undertaken repeatedly in the scientific literature. However all of these calculations possessed variety of lacks.
The formula which describes the change of the direction of the laser pulse reflected from retroreflector established on a spacecraft is deduced in the reviewed work. It considers that:
- The reflection of a light pulse at a laser ranging occurs not from a flat mirror, but from a retroreflector - the special optical device, which only in its own rest frame of reference reflects a falling light pulse strictly in opposite direction at any hade.
- The retroreflector is based in locally-geodetic frame of reference, in which in accordance with the general theory of a relativity there should be a spacecraft, if it moves under the influence of only one gravitational forces.
From the received formula follows that only at spacecraft movement along a laser beam its retroreflector reflects a light pulse in that direction, whence it has come. If the spacecraft moves perpendicularly to a laser beam its retroreflector reflects the light pulses under some corner to the direction on which they come before reflection. As estimations have shown, for laser ranging of the spacecraft which is on a low circumterraneous orbit, this corner reaches 10 angular seconds.