Networkadjusted

Networkadjusted describes data or coordinates that have been processed through a network adjustment procedure, a standard method in geodesy and surveying. In a network adjustment, a network of observations—such as angles, distances, GNSS positions, and elevations—is analyzed simultaneously to produce the most probable values for unknown coordinates while ensuring consistency with control points and a chosen reference frame. The method typically employs weighted least squares to minimize the residuals between observed measurements and their computed values. The results include adjusted coordinates, estimated parameters, and a covariance matrix describing precision and correlations. Residuals are examined to assess measurement quality and detect outliers.

Process and quality control: Observations are assembled into a mathematical model linking measurements to unknowns. Weights reflect precision; constraints from control points are applied. The normal equations are solved to obtain adjusted values, and standard checks—such as unit-weight variance and residual analysis—are used to verify the solution. If needed, reweighting or remeasurement may be performed to improve robustness.

Applications: Network-adjusted data are standard in national and local geodetic networks, GPS networks, cadastral surveys, and construction projects. This approach provides consistent coordinates across the network and alignment with a reference frame, facilitating integration of new data with existing networks.

Limitations: Accuracy depends on the correctness of the measurement model, calibration, and proper treatment of outliers. Systematic errors and correlated observations can bias results, so careful quality control and validation are essential.