An Airborne C-Band One-Dimensional Microwave Interferometric Radiometer With Ocean Aviation Experimental Results

The medium-and large-scale global sea surface temperatures (SSTs), which is an important ocean parameter, are mainly measured by space-borne microwave radiometry. However, the resolution and sensitivity are greatly limited by antenna size, orbit altitude, and flight speed. In this article, an airborne C-band one-dimensional (1-D) microwave interferometric radiometer (ACMIR) is developed to obtain the SSTs with a high resolution and sensitivity. The spatial resolution of the ACMIR ranges from 40.7 to 612 m, corresponding to the flight height of 500-8000 m, while the sensitivity varies from 0.25 to 0.36 K, associating with the boresight to the edge of the field of view (FOV). In order to evaluate the performance of the ACMIR, an ocean aviation experiment was conducted in the coastal area of the Yellow Sea in September 2020. The land observation results indicate that typical ground objects can be clearly distinguished. Furthermore, the sea surface brightness temperatures acquired by the ACMIR are compared with the estimates based on the radiative transfer model, with an SST retrieval error of 0.77 ?C. The ACMIR can offer a high resolution and accuracy of SST, especially in coastal areas, and can meet several application requirements related to SSTs.