BASIC SURVEYING or GEOINFORMATICS
Course topics:
- INTRODUCTION:
- Geoinformatics- definition, disciplines covered, importance.
- Field Surveying- definition & objectives; concept of Geoid and reference spheroids, coordinate systems, plane and geodetic surveys.
- Methods of location of a point- classification of surveys; principles of surveying.
- Errors in measurements- sources, types of errors and their treatment. Random error distribution, accuracy, precision and uncertainty. Surveying instruments- temporary and permanent adjustment concept, principle of reversal.
- Maps- types, importance, scales/CI, conventional symbols, and generalization; topographic mapsmap projection systems, sheet numbering systems, map layout.
- LINEAR MEASUREMENTS:
Direct and indirect methods; Chain and tape measurements- corrections to tape measurements; Optical methods- tacheometers, sub tense bar; Electronic methods- EDMs, total stations.
- MEASUREMENT OF ELEVATIONS:
- Various terms; Methods of height determination; Spirit leveling- different types of levels and staves; booking and reduction of data, classification and permissible closing error; profile leveling and cross sectioning; curvature & refraction and collimation errors; reciprocal leveling.
- Contours- characteristics, uses and methods of contouring.
- MEASUREMENT OF DIRECTIONS:
Bearings and angles; Compass surveying- magnetic bearings, declination, local attraction errors and adjustments; Theodolites- different types, uses, methods of observation and booking of data.
- TRAVERSING, TRIANGULATION AND TRILATERATION:
Purpose and classification of each; Compass and theologize traverses- balancing of traverses, computation of coordinates, omitted measurements. Triangulation- network, strength of figures, field work- racy, selection of stations, inter-visibility, satellite stations, measurements and computations; trigonometrical leveling.
- PLANE TABLING:
Merits and demerits, accessories; orientation and resection; methods of plane tabling; three point problem and solutions; errors in plane tabling.
- ADJUSTMENT COMPUTATIONS:
Propagation of errors, variance and covariance; Least squares principle and adjustment of field survey data by parametric and condition equation methods.
- PROJECT SURVEYS:
Engineering project surveys- requirements and specifications, various stages of survey work Setting out of works- buildings, culverts and simple circular curves.