2.0 THEORY OF ERRORS IN OBSERVATIONS

Geomatics is the new term for Surveying where as Basic Geomatics will be like Elementary Surveying. This has sprung up from the fact that the surveying tools as well as the procedures has already evolved and advanced. From the theodolites and transits used, surveyors now use the total station which gives information digitally with just one target of the telescope. 

courtesy of Bureau of Labor Statistics

Two general classes of surveying considered are plane surveying and geodetic surveying (which we can term as plane geomatics and geodetic geomatics). Plane surveying is the course taken by most students in the Civil Engineering and Architecture departments. This type of surveying considers the ground or surface as flat. On the other hand, Geodetic Engineering students take geodetic surveying wherein they would consider the earth shape as curvilinear, meaning at long distances, surveying measurements would have to be influenced by the Earth's curvature.

The different types of surveys are:

1. Cadastral survey - surveys for the purpose of locating property lines and boundaries.
2. City survey - surveys dealing with areas and boundaries but for planning expansions and improvement of the city.
3. Construction survey - survey conducted to determine the building lines and grades at the construction site.
4. Forestry surveys - surveys intently for forest management.
5. Hydrographic surveys - those surveys involving bodies of water.
6. Industrial surveys - surveys for industrial zoning.
7. Mines surveys - surveys used for underground excavations.
8. Photogrammetric surveys - surveys using photographs.
9. Topographic survey- survey used for determining the terrain of the ground and the other features present.
10. Route survey - survey primarily to lay out roads and highways or passages.

2.0 THEORY OF ERRORS IN OBSERVATIONS


The most probable value is basically using the same formula for averaging. However, in cases where the student is asked to determine multiple most probable values, the equation does not stand as is. It would be more procedural where the student should know in which parameter he will have to compare the given. Comparing the observed and standard value will give you the discrepancy which we can term as error. This error in turn will be divided on how many sets are in the problem to distribute this error equally (the result is what we call correction). From this correction, you can conclude to the most probable value by either adding or subrtracting it (depends on the comparison).

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