摘要: This report presents the results of two studies conducted at the Department ofGeodetic Science and Surveying in conjunction with the use of GPS in applications for ODOT's Aerial Engineering tasks. The first deals with the implemen... 展开 This report presents the results of two studies conducted at the Department ofGeodetic Science and Surveying in conjunction with the use of GPS in applications for ODOT's Aerial Engineering tasks. The first deals with the implementation of computer code to determine the position of an airplane precisely using signals from GPS. In addition to positioning an airplane with GPS alone, Inertial Navigation System (INS) technology is now at the level where one could consider augmenting GPS with other information. GPS gives excellent positioning information at fairly long intervals in time (one second), while INS does well at much shorter intervals. Thus a review of potential benefits is provided in the second half of this report. A review on INS hardware and typical operation is followed by some numerical analyses that demonstrate the utility of the aiding process for two types of INS: a medium-to-high grade navigation quality INS and a lower accuracy unit. Particular emphasis is placed on unknown accelerometer biases that dominate the short-term INS positioning uncertainty. Several corresponding stages of self-calibration are indicated. Two appendices include the mathematical framework for state-space estimation of the position errors as well as Kalman filtering and smoothing algorithms. Major conclusions deals with improved interpolation of position from discrete evaluation plus handling GPS outages, which can happen due to blackages by tail section and, electrical interferences. 收起