Precise Attitude Determination Using a Hexagonal GPS Platform
A. Arsenault, and S. Sud. Signal Processing: An International Journal (SPIJ)14
1-14 (October 2021)
In this paper, a method of precise attitude determination using GPS is proposed. We use a hexagonal antenna platform of 1 m diameter (called the wheel) and post-processing algorithms to calculate attitude, where we focus on yaw to prove the concept. The first part of the algorithm determines an initial absolute position using single point positioning. The second part involves double differencing (DD) the carrier phase measurements for the received GPS signals to determine relative positioning of the antennas on the wheel. The third part consists of Direct Computation Method (DCM) or Implicit Least Squares (ILS) algorithms which, given sufficiently accurate knowledge of the fixed body frame coordinates of the wheel, takes in relative positions of all the receivers and produces the attitude. Field testing results presented in this paper will show that an accuracy of 0.05 degrees in yaw can be achieved. The results will be compared with a theoretical error, which is shown by Monte Carlo simulation to be < 0.001 degrees. The improvement to the current state-of-the-art is that current methods require either very large baselines of several meters to achieve such accuracy or provide errors in yaw that are orders of magnitude greater.