This paper demonstrates as compared with the visible and infrared sensor that microwave sensor possesses unique advantages on resolution of images imaging rate and signatures within the image. It is enough to prove that the microwave sensor is the current focal point for developping new sensor in progress of remote sensing techniques. The principle of passive microwave remote sensing is discussed. Some characteristics and quality indexes of the different microwave radiometers are compared also. Design plans

key techniques and primary specifications of various airborne microwave radiometers are given. These radiometers were developed by Changchun institute of physics

Chinese Academy of Sciences

Especially

the design specifications of the Dicke type radiometer systems with negative feedback and null-balancing mode are deliberated as well. These sensors have four frequency band and are suitable for applications of remote sensing on land

ocean and atmosphere. In addition

the paper deals with the scanning of the antenna

the collecting of the data controlled by microcomputer

the processing and correcting of the digital microwave radiometric imagery; and the method of synchronous video recording. In the pass nine years

the passive microwave sensors as mentioned above were put into the flight tests for surveying earth’s resouces and monitoring natural environment. It has been proved that these sensors are sensitive

stable and reliable. In short

the microwave remote sensing has a vast prospect in applications