Spaceborne radar clock drifting on-orbit correction method based on active calibrator

Abstract

The invention provides a spaceborne radar clock drifting on-orbit correction method based on an active calibrator. The spaceborne radar clock drifting on-orbit correction method based on the active calibrator comprises the steps that spaceborne radar pulse signals are tracked, received and transmitted through the active calibrator, the clock drifting distance of spaceborne radar is obtained by comparing an active calibrator distance parabola and a spaceborne radar distance parabola, and real-time quantitative monitoring of the operating state of a spaceborne radar clock is achieved based on the clock drifting distance of the spaceborne radar. According to the spaceborne radar clock drifting on-orbit correction method based on the active calibrator, the clock drifting distance of the spaceborne radar is measured accurately with an independent method for the first time, testing can be conducted in any position within the coverage of wave beams of the spaceborne radar and at any time when the spaceborne radar is in transit according to the method, the space-time flexibility is high, and the requirement for absolute timing reference for the active calibrator does not exist due to the fact that the pulse intervals are received by the active calibrator on the ground to serve as analysis data; meanwhile, path errors caused by the air when the spaceborne radar signals are transmitted are eliminated, and the clock drifting distance of the spaceborne radar can be measured accurately in real time.

Description

technical field [0001] The invention relates to the technical field of spaceborne radar remote sensing, in particular to an on-orbit correction method for spaceborne radar clock drift based on an active scaler. Background technique [0002] During orbital operation, the spaceborne radar transmits pulse signals to the ground and receives the reflected echoes of objects on the ground, and determines the distance from the spaceborne radar to the measured target by measuring the round-trip time of the pulse. The spaceborne radar altimeter is such an active spaceborne radar pointing to the sub-satellite point. During in-orbit operation, the spaceborne radar emits pulse signals vertically downward, and the signals are reflected by the earth's surface (sea, land, ice) or other ground targets and return to the spaceborne radar receiving antenna. Spaceborne radar can determine the distance from its center of mass to the sub-satellite point by measuring the pulse round-trip time, and...

AI Technical Summary

Problems solved by technology

[0005] Before the spaceborne radar is launched, its clock frequency can be directly measured by using a frequency meter or a spectrum analyzer; during the spaceborne radar’s in-orbit operation, it cannot be directly measured

At present, no method has been found at home and abroad to specifically measure the clock drift during the on-orbit operation of the spaceborne radar. In the world, the error caused by the clock drift and the inherent deviation of the hardware system of the spaceborne radar are generally processed comprehensively. Total error of track measurement

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