Assessment Progress:

These self-assessment problems accompany the mini course Key Statistical Concepts for Geomatics Networks.

Problem 1*

Imagine you’re given the situation shown below where the azimuths of points 2, 3, and 4 are each measured at point 1, and found to have the values and standard deviations shown in the table.

error-propagation-problem
azimuth measurement standard deviation
(arc seconds)
az_{12} 45^o14'42.360" 4.1
az_{13} 92^o6'48.816" 6.8
az_{14} 151^o13'17.220" 7.2

a) Compute the angles \theta_{23} and \theta_{24}, and use propagation of errors to calculate their variance-covariance matrix

b) Find the error correlation coefficient between the angles \theta_{23} and \theta_{24}

c) Interpret the sign of the off-diagonal elements of the variance-covariance matrix, and the sign of the error correlation coefficient