Spaceborne interferometic microwave radiometer and calibration method thereof

Abstract

The invention relates to a spaceborne interferometic microwave radiometer comprising an earth observation antenna array, a cold sky calibration antenna, a public noise source, a noise-source multiway power divider, a cold sky multiway switch, receiver front-end multiway switches, Dick type receivers and earth observation receivers. The earth observation antenna array comprises multiple earth observation antennas, antenna beams of the earth observation antennas deviate from an antenna plane normal and obliquely point to the ground; the two earth observation receivers are mounted behind each earth observation antenna; antenna beams of the cold sky calibration antenna are opposite to the antenna beams of the earth observation antennas and constantly point to the cold sky; the cold sky calibration antenna is connected to all the receivers; the public noise source is connected with all the receivers; a matching load is mounted at the front end of each receiver; the Dick receivers are operated under the Dick mode; the earth observation receivers are connected with the cold sky calibration antenna, the earth observation antennas, the matching loads and the public noise source.

Description

technical field [0001] The invention relates to the field of instrument calibration, in particular to a spaceborne interferometric microwave radiometer and a calibration method thereof. Background technique [0002] The interferometric microwave radiometer is a passive microwave remote sensor, which is mainly used in technical fields such as earth observation and space astronomy. Microwave radiometers receive natural radiation signals from targets. The power level of the received signal depends on the emissivity of the target as well as the physical temperature of the target itself. After accurately measuring the power level of the received signal, physical parameters such as temperature, surface roughness, and dielectric constant of the target can be further obtained. [0003] However, since the natural radiation signal is very weak, small changes in the noise temperature and gain of the receiver itself will seriously affect the measurement accuracy of the radiometer. The...

AI Technical Summary

Problems solved by technology

There are many problems in this method, such as the difference between the sun’s incidence angle and the earth observation attitude when observing the cold sky as a whole, the too long calibration period affects the earth observation, and the periodic flipping of satellites consumes fuel to affect the life of the satellite, etc., making the interferometric microwave radiometer In the field of quantitative high-sensitivity applications, there is insufficient capability, which affects the breadth and depth of interferometric microwave radiometer applications

Images