Standalone Multi Antenna GNSS Code Based Attitude Determination of Nanosatellite: Design and Implementation

Abstract

The attitude determination of nanosatellite has been performed in many satellite missions using different sensors like magnetometer, gyroscopes and sun sensors but the cost, weight and power requirements motivate the researchers for standalone GPS based attitude determination system. The attitude determination of the Cubesat projects can be obtained by using the code based measurements from at least three commercial- off- the- shelf (COTS) GPS antennas/receivers mounted on the surface of the satellite with known baseline measurements. Although the code measurements are not as accurate as the phase measurements, but it can give the accuracy of one degree that is sufficient for the experimental Cubesat projects. This research contribution presents the GPS code-based attitude determination algorithm while post processing the static test data and implementing the algorithm in MATLAB environment. The single-point positioning is used for determining the position of the Master antenna, and differential positioning is done to find the slave antennas' position and baseline coordinates. Finally, attitude is determined and compared using the least square and direct methods. Various GPS signal and system errors like ephemeris, clock. Ionospheric and Tropospheric errors along with satellite geometry are also calculated.

An All-Fiber Optical Sensor Combined with FBG and CFBG-FP for Attitude Estimation

“…However, the marine environment has an obvious inhibitory effect on the transmission of electromagnetic waves [ 4 ]. At present, the attitude acquisition devices used in astronomical navigation systems and satellite navigation systems [ 5 , 6 , 7 ], which are commonly utilized in ground and aviation systems, are challenging to employ in underwater systems. It should be noted that inertial sensors are able to carry out attitude estimation.…”