Covariance Analysis

Analytical uncertainty covariance matrices for both points and instrument base locations can be generated as *.csv file output.

Methods employed are those as described in the paper “On the Representation and Estimation of Spatial Uncertainty” by Randall C. Smith and Peter Cheeseman published in “The International Journal of Robotics Research”, Vol. 5, No. 4, Winter 1986.

x^2 is the Chi-Squared error

M = number of observations (number of rows in a matrix)

n = degrees of freedom (number of variables to solve – number of columns in a matrix)

nominally, (M – n) = x^2 when expected error is consistent with observed error.

Uncertainty covariance report includes:

The input points used to develop a composite point are used to generate an error covariance matrix. This data may be helpful in terms of evaluating the data spread of the input points about the composite point. This data will not be generated for any composite point with less than three input points.

R-Click on “CoVar” button will allow the user to experiment with different values of singular value tolerances (default is 0.01).