Fig. 1. Height measurement geometry of interferometric imaging radar altimeter

Fig. 2. On-orbit processing flowchart of interferometric imaging radar altimeter

Fig. 3. On-orbit imaging algorithm of interferometric imaging radar altimeter

Fig. 4. Imaging result of Tiangong-2 interferometric imaging radar altimeter

Fig. 5. The method of image registration based on target position estimation

Fig. 6. Geometry of target position and radar sight line

Fig. 7. The standard deviation of height measurement error based on orbital parameter method and target position estimation method

Fig. 8. The interferogram before and after flat earth removal

Fig. 9. Relationship between GPS error and flat-earth phase error

Fig. 10. Influence of multi-look processing on interferometric phase error

Fig. 11. Interferogram after interpolation average multi-look

Fig. 12. Height measurement error between on-orbit processing and ground processing

Fig. 13. Algorithm error in different ground resolution