Sea ice is an important element affecting heat circulation of the earth. Based on the heat emission of sea ice and sea water

the paper analyzes a 3 layer medium at sea surface used to sense sea ice and derives the following model relating intermediate medium to the received emission brightness temperature: T B=A+Be -CD where A

B and C all depend on polarization

observation angle and frequency of the remote sensing system

they can be deduced from sea ice in situ measurement on ground. The model agrees with propagation features of electromagnetic wave in loss medium and reflects the relationship between the received energy by passive microwave remote sensing system and the propagation distance. In recent years

4 bands of microwave radiometers were used to measure sea ice on ground （0 degree observation angle） and 3 of them were used in aerial remote sensing

two results are basically in agreement. The fact shows that the model is correct and feasible. Sea ice thickness distribution along the flight line over Liudongwan Gulf and statistical curve relating brightness temperature to ice thickness are given. Several factors affecting measurement and limiting ice thickness identification are pointed out.