These days I am using Top-con Total Station. That top-con software has some thing called " Grid Factor".
I am using SLD 99 Sri Lanka coordinate system and used GPS to establish few control points at site.
My problems are
- Should I care Grid Factor when doing large scale surveying and setting out?
- What is the real idea of Grid Factor ?
- Why this grid factor setting not in Sokkia instruments?
I found this information from top-con manual.
1) Elevation Factor
Elevation Factor = R R : The average radius of the earth
R+ELEV. ELEV. : The elevation above mean sea level
2) Scale Factor
Scale Factor : Scale Factor at the surveying station
3) Grid Factor
Grid Factor = Elevation Factor × Scale Factor
1) Grid Distance
HDg = HD × Grid Factor HDg : Grid distance HD : Ground distance
2) Ground Distance
HD = HDg
Welcome any idea and Thanks for helping