Least Squares measurement adjustment principles and concepts, with particular reference to surveying observations of distance, height difference, angular directions, GPS solutions. Determining input into, and analysing output from, typical Least Squares adjustment software. Inside Least Squares: Modelling observations, observation equations, parametric method, condition and combined methods, linearisation of equations, derivation of Least Squares algorithm, methods of forming normal equations. Variance-covariance matrices, measurement uncertainty, and error ellipses, and in particular the application of statistics and error analysis in surveying. Worked examples and case studies from various areas of cadastral and engineering surveys. Calibration of EDM instruments.