1. Working from whole to the part
The survey work is carried out from a larger scale to a smaller scale. The surveyor first establishes a network of control points that cover the entire area to be surveyed with a high level of accuracy. These control points are then used as references for surveying smaller areas or details within the larger area. This way, the errors and uncertainties in the measurements are minimized and controlled.
2. To locate a point by measurement from two fixed reference points
The position of a new point can be determined by measuring its distance or angle from two existing points whose positions are known. The surveyor can use various instruments such as chains, tapes, compasses or theodolites to measure these distances or angles. This principle is based on the concept of triangulation, which is a method of finding the location of an object by forming triangles with it and two other known points.
3. Independent check
Every measurement or calculation that is done in the survey work is verified by another independent method or person. This is done to ensure that there are no mistakes or errors in the data or results.
4. Consistency
The same units, standards, methods and procedures are used throughout the survey work to avoid errors and confusion. The surveyor should follow the rules and conventions that are established for his or her field of work and use consistent notation and terminology.
5. Safeguarding
The survey data and records are protected from damage, loss or alteration by proper storage and backup. The surveyor should keep all his or her field notes, sketches, maps and reports in good condition and safe places. He or she should also make copies or backups of these documents in case they get lost or destroyed by accident or natural disaster.
6. Economy of accuracy
The degree of accuracy required for a survey depends on its purpose and cost. The surveyor should not aim for too much accuracy that exceeds what is needed for his or her objective because it will result in a waste of time, money and resources. The surveyor should also not aim for too little accuracy that falls short of what is needed for his or her objective because it will result in poor quality and unreliable data.
7. Honesty
Honesty is an essential principle in surveying as it ensures that the data collected is accurate and reliable. Surveyors must be honest in booking notes in the field and when plotting and computations in the office. There is nothing to be gained from cooking the survey or altering the data, and it can lead to disastrous consequences.
fig: Total station
