2 results about "Orbital speed" patented technology

The application discloses a high-precision time offset autonomous calculation method and system based on satellite speed v and gravity acceleration g. By establishing a closed correlation between the gravity field strength and the orbital speed, the traditional multi-parameter relativistic time correction model is simplified to a closed-form calculation depending on only two in-orbit measurable physical quantities, without the need for input of orbital radius, universal gravitational constant, earth mass, external ephemeris, etc. The application has outstanding originality, simple calculation, strong autonomy and reliable precision, can realize a daily cumulative time error of less than 1 ns, is suitable for low-orbit satellites, navigation satellites, constellation systems and various high-reliability time service scenarios, has a wide application range and high industrial value, and can significantly improve the autonomous time service capability of a spacecraft and the stability of a time system.

The present application belongs to the technical field of remote sensing measurement of ocean surface current velocity, and in particular to a Lujia-2 SAR current velocity correction method based on Bragg orbital velocity, comprising the following steps: verifying the physical correctness of the orbital velocity mechanism relative to the phase velocity mechanism; and under the DopRIM framework, establishing a physically consistent sea wave error correction model; calibrating the parameters of the sea wave error correction model; applying the calibrated sea wave error correction model to Lujia-2 satellite along-track interferometric SAR observation data to calculate the radial surface current velocity and sea wave error of each resolution unit; comparing the output results with the matched reference true value to evaluate the effectiveness of the sea wave error correction model; comparing the sea wave error correction model with the KaDOP model, respectively, to statistically analyze the simulated sea wave error under different methods; visualizing the sea wave error simulation results, and quantitatively evaluating the improvement effect through in-situ observation data and KaDOP simulation results.