Theory of Errors & Plane Table Surveying
Theory of Errors, Occurrence of Error- Imperfection in Instruments, Environmental Condition, Human Limitations & Carelessness, Type of Error– Gross Errors or Mistakes, Systematic or Cumulative Errors, Accidental or Random errors, Important Terminology- Precision, Accuracy, True Value, True Error, Most Probable Value (M.P.V), Principle of Least Square, Residual Error. Law’s of Weights, Probable Error– Probable Error in Single Measurements, Probable Error in Mean (MPV), Probable Error of Single Measurement of Weight, Error In Computed Result.
Plane Table Surveying, Accessories Used in Plane Table Surveying- Plane Table Board, Alidade (for orientation), Tripod (for stand), Level Tube/ Spirit Level (for leveling), Compass (for orientation), Plumbing Fork (for centering), Procedure, Setting up the Plane Table- Centering, Levelling, Orientation: Orientation with a Trough Compass, Orientation by Back-Sighting, Resection. Method Of Plane Table Survey– Radiation Method, Traversing Method, Intersection Method, Resection Method- Compass Method of Resection, Back Ray Method of Resection, Two Point Problem of Resection, Three Point Problem of Resection.
Topics
In liner measurements,we details discuss about procedure in chain surveying,basic definition of chain surveying- main station, tie station, main survey line, tie line/ subsidiary line, base line, check line/ proof line, offset, chainage, well conditioned triangle.Correction in chaining,limiting length of offsets.
In tacheometry we details discuss about tacheometry, instrument used in tacheometry, tacheometer, stadia rod, stadia system, fixed hair system, movable hair system, tangential system, subtense bar system, theory of tacheometer, distance and elevation through tacheometer when a staff is vertical & staff is perpendicular to line of sight.