Correcting INS Drift in Terrain Surface Measurements

摘要

Modern terrain measurement systems use an inertial navigation system (INS) to measurenand remove vehicle movement from laser measurements of the terrain surface. Instrumentalnand environmental biases inherent in the INS produce noise and drift errors innthese measurements. The evolution and implications of terrain surface measurement techniquesnand existing methods for correcting INS drift are reviewed as a framework for annew compensation method for INS drift in terrain surface measurements. Each measurementnis considered a combination of the true surface and the error surface, defined on anHilbert vector space, in which the error is decomposed into drift (global error) and noisen(local error). The global and local subspaces are constructed such that the drift isnmodeled as a random walk process and the noise is a zero-mean process. This theoreticalndevelopment is coupled with careful experimental design to identify the drift componentnof error and discriminate it from true terrain surface features, thereby correcting the INSndrift. It is shown through an example that this new compensation method dramaticallynreduces the variation in the measured surfaces to within the resolution of the measurementnsystem itself.