Infrared radiation measurement is one of the important ways for target signature acquirement and target recognition, wherein atmospheric correction is a requisite step for obtaining the real radiation of the target. In the conventional radiation measurement method, it is necessary to measure atmosphere parameters by using atmosphere observation devices, and calculate the atmospheric transmittance and the air path radiance from these parameters by using a atmospheric radiation transport calculation software. The uncertainty in the atmospheric transmittance obtained by the conventional method is about 10~20%, and the target radiation inversion precision is about 12~23%. To improve the radiation inversion precision, a novel radiation measurement method based on realtime correction was presented, which measured the atmospheric transmittance with high precision by using a reference blackbody near the target. Models for atmospheric transmittance calculation and target radiation inversion were proposed. Analysis showed that the uncertainty in the atmospheric transmittance obtained by the novel method is about 6~10.5%, and the radiation inversion precision obtained by the novel method is better than 3.5%. A radiation measurement was performed by using a MW infrared camera. Theresults showed that the radiation inversion precision of the conventional method is 7.5～24.7%, while that of the novel method is 0.1~3.4%. The novel method has an important significance for improving the target radiation inversion precision.