Survey 6
Property resurvey
The aim is to find a location of given objects (against a baseline). For example, you are given a task by a prospective buyer to map current situation of the property. Or a new structure has to be built therefore current buildings and infrastructure have to be mapped for the design.
Baseline is given by two known points: typically by monuments at points of beginning (POB). These points might be provided and supervised by government agency. For purposes of our survey, we will consider one of them is at [0, 0] and the azimuth to the other is 70 °.
Objects given to measure are buildings and/or fence.
The procedure
1—Baseline of known location and object to measure
2—Polar coordinates (angle and distance) are taken
3—Rectangular coordinates (plus and offset) are taken
4—Linear coordinates (two distances) are taken
5—Focal coordinates (triangulation) are taken
6—When the position is determined, sides of the building are taken also
Total station + its target and tape will be used.
The setup can not be placed into the POB because POB is defined by an obstacle (a pole, column, pillar, ...). Thus we have to establish another two temporary stations. These temporary stations will form a new baseline and have to be choosen in such locations, so they will be useful and practical to find coordinates of points of interest.
The temporary stations can be located by a variety of methods. For example by means of traverse (note that since we do not know the coordinates of POBs, we can not close the loop and we have no check against errors).
Evaluation
Consider POB at [0, 0] and the azimuth between POBs to be 70 °. Evaluate the coordinates of the objects. Make a drawing of located objects.
