Comparison and evaluation of retrieved ozone profiles from solar backscatter ultraviolet sounder on FY-3A satellite

In order to evaluate the precision and stability of ozone profiles from the Solar Backscatter Ultraviolet Sounder (SBUS) on FY-3A satellite, the retrieval experiments were carried out by using SBUS measurements and the ozone profiles from SBUS and those from SBUV/2 on NOAA satellites were compared. Firstly, on the basis of FY-3 ozone profile retrieval algorithm FY_V1.0, the ozone profile retrievals were undertaken by using the SBUS measurements during 17 July to 30 August 2008 as input data. Then, three kinds of methods were proposed to compare the retrieval data of SBUS with those of SBUV/2. These methods are the direct comparison of SBUS ozone profiles with those matching profiles of SBUV/2, comparison of SBUS mean ozone profiles with those of SBUV/2 in tropics and the comparison of residuals of retrieved and apriori ozone profiles of SBUS and SBUV/2. Finally, the comparison and evaluation results were analyzed. Comparison results indicate that the relative bias percentage of SBUS ozone profiles relative to those of SBUV/2 at matching pixels are within ±10% at most layers, but reaches ±15% at fewer layers; the differences of SBUS mean ozone profile with that of SBUV/2 in tropics are smaller than ±0.3 DU at most layers. The biggest difference is 5.4 DU and the smallest is 0;the comparison of the residuals of retrieved and apriori ozone profiles shows notable difference between SBUS and SBUV/2 in the height of residual occured and the negatives and positives of the residuals. It is concluded that the precisions of SBUS ozone profiles are pretty good at most layers without doing any correction. But, there exists some remarkable differences between SBUS ozone profiles and those of SBUV/2. To improve the precisions of SBUS ozone profiles, it is necessary to put efforts on measurement correction based on inter-calibration with SBUV/2.