What problems does geodetic adjustment solve?
- How do you determine the most probable coordinates when multiple measurements do not match exactly?
- How do you handle measurement uncertainties and differences in accuracy between observations?
- How do you identify errors and anomalous observations in a geodetic network?
- How do you assess the precision and reliability of calculated coordinates?
- How do you combine different types of geodetic observations within a single adjustment?
- How do you assess whether a geodetic network is sufficiently reliable for its intended use?
Geodetic measurements always contain uncertainties and small measurement deviations. When a point is measured multiple times or from different directions, the observations will therefore almost never match each other exactly. Geodetic adjustment provides the mathematical and statistical methods to combine these observations in a sound manner.
During this Blended Learning course, you’ll learn the theory and principles behind geodetic adjustment. You’ll learn not only how to perform an adjustment, but especially how to evaluate the results and interpret them geodetically. You’ll then apply this knowledge in practice using MOVE3D.
The Theory Behind Geodetic Adjustment
A good adjustment begins with an understanding of observations, measurement errors, and uncertainties. You’ll learn why geodetic observations are never completely error-free and why redundant observations are necessary to assess the quality of a measurement network.
You’ll be introduced to concepts such as precision, reliability, variance, standard deviation, weights, and correlation. You’ll also learn to distinguish between random, systematic, and gross errors and understand how they can affect the final result.
You will then be introduced to the least-squares method and the principles of geodetic adjustment. The goal is not only to be able to perform the calculations, but above all to understand what happens during an adjustment and why certain observations have a greater or lesser influence on the final result.
Geodetic Networks and Observations
Within a geodetic network, various observations are combined to determine the position and, if necessary, the elevation of points as reliably as possible. You will learn how a survey network is constructed and what role known points, unknown points, and redundant observations play in it.
You will work with various types of observations, such as distances, directions, angles, elevation differences, and coordinates. In doing so, you will learn how the accuracy of these observations is taken into account in the adjustment.
The course also covers the determination of approximate coordinates, network loops, and loop closure errors. You’ll learn how to assess, even before the final adjustment, whether the observations are logical and consistent and where potential problems in a survey network might lie.
Precision, Reliability, and Quality Control
An adjustment does not merely yield new or improved coordinates. Equally important is the information regarding the quality and reliability of these coordinates and the underlying observations.
You will therefore learn how to evaluate the results of an adjustment. You will examine corrections to observations, standard deviations, coordinate precision, and other quality indicators that can be used to determine whether a survey network meets the specified requirements.
In addition, you’ll learn how to identify anomalous or potentially erroneous observations. This will enable you not only to perform a adjustment but also to justify why the final coordinates are sufficiently accurate and reliable for their intended use.
Geodetic Adjustment with MOVE3D
After covering the theoretical foundations, you will apply the principles of geodetic adjustment in practice using MOVE3D. The software serves as the tool through which you will learn how to apply the theory to a real-world geodetic network.
You’ll learn to process measurement data and various types of observations in MOVE3D and to adjust a network. In doing so, you’ll work with 1D, 2D, and 3D problems and investigate what happens when observations, weights, or initial conditions are adjusted.
The emphasis is not solely on performing the calculations. Above all, you’ll learn to read, analyze, and interpret MOVE3D’s output from a geodetic perspective. This will help you develop the insight needed to assess whether an adjustment is reliable and which observations or parts of the network require additional attention.
Geodetic Adjustment in Practice
During the Blended Learning program, you’ll work with realistic geodetic measurement data and networks. You’ll step into the role of a geodetic specialist and assess not only the calculated coordinates but also the quality of the observations and the entire measurement network.
Among other things, you’ll work on assignments such as:
- Check a geodetic measurement network for network loops and loop closure errors before performing the adjustment.
- Determine approximate coordinates and use them as a starting point for an adjustment.
- Perform an adjustment using MOVE3D based on various types of geodetic observations.
- Investigate how different levels of accuracy and weights assigned to observations affect the results.
- Analyze the adjustment results and identify anomalous or potentially erroneous observations.
- Assess the precision and reliability of the calculated coordinates and determine whether the network is suitable for its intended use.
By the end of the course, you will understand the theoretical principles behind geodetic adjustment and be able to explain why adjustment is necessary for reliable geodetic results. You will be able to evaluate a geodetic network, combine different observations, and perform an adjustment in practice using MOVE3D. In addition, you will be able to analyze the results and substantiate whether the calculated coordinates and the geodetic network are sufficiently accurate and reliable.
