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Egypt Engineering Consultant Civil study materials
Egypt Engineering Consultant Civil study resources

Egypt Engineering Consultant Civil: Surveying and Geomatics

Egypt Engineering Consultant Civil · Work through your exam, one topic at a time.

All guide sections

Surveying and Geomatics

Surveying and geomatics questions test your ability to reduce field observations into coordinates, levels and areas, and to recognise the error sources that invalidate a survey. The exam expects traverse computations, level-book reduction, coordinate geometry and awareness of Egyptian cadastral and geodetic practice.

Core rules and concepts

  • Leveling: height difference = backsight − foresight. Reduce levels in a level book and close the run on a known benchmark. Misclosure is distributed according to distance or number of setups, depending on the specification.
  • Traversing: compute latitudes and departures from length and bearing: ΔN = L cos θ, ΔE = L sin θ, with bearings measured clockwise from north. A closed traverse should sum to zero; any misclosure is adjusted by Bowditch or transit rules before coordinates are computed.
  • Angular misclosure: compare the sum of measured angles with the theoretical sum for the polygon; distribute the correction before computing bearings.
  • Curvature and refraction: leveling over long sights requires correction; keep sight lengths balanced and short.
  • GPS/GNSS: distinguish ellipsoidal height from orthometric height, and be aware of projection scale factors and geoid models.

Worked example

From point A (E = 1000.00 m, N = 2000.00 m), line AB has length 100.00 m and bearing 30°. ΔE = 100 sin 30° = +50.00 m; ΔN = 100 cos 30° = +86.60 m. Therefore B = (1050.00, 2086.60). Line BC has length 150.00 m and bearing 120°: ΔE = 150 sin 120° = +129.90 m; ΔN = 150 cos 120° = −75.00 m. Therefore C = (1179.90, 2011.60). If the traverse closes with ΣΔE = −0.08 m and ΣΔN = +0.06 m over a perimeter of 500 m, the misclosure is corrected before these coordinates are adopted for design or cadastral work.

Traps that cost marks

  • Reversing the sine and cosine when computing departures and latitudes.
  • Using bearings measured from the east instead of north.
  • Applying angular correction after coordinates have been computed.
  • Ignoring scale factor when converting GNSS coordinates to ground distances.
  • Treating a closed level run as acceptable without checking permissible misclosure.
  • Mixing reduced level and height difference.