To achieve fast and large-scale monitoring of global sea surface heights (SSH), we designed a Global Navigation Satellite System (GNSS) altimeter with in-loop optimization. By measuring the delays between the reflected and direct GNSS signals, we were able to calculate the sea surface height. In Global Positioning System (GPS) altimetry, receivers must collect reflected GNSS signals from the ocean surface. However, this can be affected by high mobility issues and weak received signal power. Therefore, we adopted an open-loop tracking strategy along with optimized loop filtering on the Field Programmable Gate Array (FPGA) altimeter to overcome these limitations. In addition, further dual-frequency GPS signal processing was applied in order to conduct the proposed cross-path ionospheric error calibration, achieving a better ranging performance. To verify the effectiveness of the proposed altimeter, flight tests using a Gulfstream Jet were conducted; the real-time performance is demonstrated.
All Science Journal Classification (ASJC) codes
- Aerospace Engineering
- Space and Planetary Science