TOPOGRAPHIC MEASURMENT

Crew Topografi

Process Measurment Total Station

Measurement made using the method stake out the ETS(electronic total station),this method is to place the position of the point coordinates in the field based on theoreticaldata.measurement bound to control point it aims to keep those point are not far off the mark too with theoretical coordinates on a new trajectory measurement,Determination point made by making the point nearest BM as a tie point.measurement of the direction and distance to reading of stakes in the ETS which is the position of the stick prism. stick prism placed in the position in accordance with coordinates theoretical ,during measuring stick we use theree sets of prism,one to fore shoot.one to point shoot ,shoot back and fore shoot in a stationary position while the point shoot point shiet in accordance with who wants at the measuring point .After that shoot fore position serve as the position of the ETS,or commonly referred to as sentring force whereas ETS position previously used as back position back position shoot,The data are taken is the distance side because of the distance we gain altitude oblique.Azimuth of the sun at least once in the beginning or end of measurement on day stake out coodinates is major activity in the field of topographic survey,in this method use tool set 303 SOKKIA.This tool is used to determined trace point and shootpoint in the field which data is sourced from the coordinates were determined also theoretical in addition from MSL to trace points and shootpoint used different peg.to trace a bule peg while for red then point,shoot point to start and ending coordinates of the line is determined by client. Usually for the source in 2D only odd shoot point but is skipped if the terrain does not allow the production of SP add ( such as settlements,rivers,etc ) then made SP,SP even to compensate the lost,so that the distance between normal with SP,SP compensation to 30 meter,geometric differences betweet 3D and 2D seismic located on the source and trace placement.for 2D source and is loceted on one line, even through in 3D source and trace lies in the line that there is different where there are source line (SL) and the receiver line (SL).for the measurment of the initial measurment optimasi (start line) is not made at the beginning or end of the line. This is caused not yet available access to the beginning or end of the line,to overcome the problem,there are several ways that made them :
1. Measurment traverse ,this measurment is essentially bound to make a perfect polygon of GPS points,which has been observed,which was made in the control placement of traverse points in the place sepressi possible with the intersection line,rejuvanate the start line.
2. Translock coordinates,on principle this process is same as the binding to the faces of polygon,where the set 2. Pieces of GPS point in determining the point translock belt.Before performing topographic measurments,firts,conducted in coordination with departements and other sub-jobs, especially those adjacent to the measurment time job topography,such as path ,bridging and drilling.This is done so that does not happen the chase time job,let alone overlap.After disscussion made the program schedule.The first program topography measurment ,which in turn followed path,bridging,drilling,recoording .Department of topo also do work side by side against the other department such as explanation access location, the existence of trace stakes and shoot point ,until the offset and compensation.Tecnically,before doing stake out work,first ferformed to define the azimuth measurment sunshot beginning of the start point line.Further measurments were taken stake out,which coordinates the existing theoretical and entered on memory device and asked to determine the coordinates of the trace point and shot in the field .The points trace and shot point is determined from the points already fixed polygon or in other words the points polygon is a point of basic frame work.At the end of the measurment was repeated sunshot as the final azimuth control and then crossing between the line.Then fix the binding,at that point,the process of 3D seismic stake out the coordinates.measurments were taken at the start line,then tied in a single block,to get the cordinates of the point of each loop block. The block are separated into several swath according to the number of SL and RL,block width is adjusted with the precision of the distance.Each block covers precision is inversely proportional to its distance,then a big correction. As much as possible this block to close at each end of the SL and RL,so that the coordinates of the point produced mord good blocks. At the time of measurment,were also planting seismic BM. BM is made to reconstruct the point line is needed, if any program devolopment survey .BM seismic are :
- Uneven distribution of BM (cover) the whole line .
- To socialize with people .BM is an important point not tobe disturbed. BM seismic and BM GPS is a point for defining the datum if the reconstruction will be done.