Correction Procedure for MTVZA-GYa Georeference

This paper presents a description of an approach that makes it possible to control the quality of the MTVZA-GYa georeferencing and determine the optimal values of the corrective parameters. The analysis of the data of this instrument showed that the main contribution to the georeferencing errors are made by the angles of roll, pitch and yaw, which determine the mismatch between the instrumental coordinate system and the spacecraft coordinate system. In this regard, an iterative algorithm for detecting these angles was proposed, where the difference in measurements on the ascending and descending orbit half-passes of the MTVZA-GYa was used as the minimized function. As a result of applying this algorithm to the results of measurements of the MTVZA-GYa for 2020, the average values of the correcting roll, pitch and yaw angles of this instrument were calculated. The following values were found: (–0.84 ± 0.15)° for yaw angle, (–0.44 ± 0.14)° for roll angle and (+1.13 ± 0.05)° for the pitch angle. It was shown that the introduction of these angles into the MTVZA-GYa georeferencing procedure can significantly reduce its errors. Thus, the average discrepancy between coastlines borrowed from high-precision geographic databases and reconstructed from radiometric portraits is 4.5 km when georeferencing is performed using this correction angles.