Download - Department of Land Resources

RFP for ANAND & other Seven DISTRICTS Resurvey project
Annexure I Ground Control Network & Monumentation
There shall be Ground control Network at 4 levels (incase of non availability of (SOI) data,
GCN at 5 level
All the control points should be based on datum given below:
Horizontal Datum : WGS-84 (i.e. the latest version of the World Geodetic System standard
for use in cartography)
The Primary Control points of the Survey of India (SOI), provided by static GPS observations
(72 hours) with dual frequency GPS receivers, should be used as reference points for
preparing district net work to link the district with national survey net work.
In case of non availability of SOI data of network control points ,same kind of data and
control points should be established in consultation with SOI and prepared by the vendor
with MSL datum as per below mentioned standards .
Base Station: At centre of Area of Interest (AOI) With minimum 72 hour observation by
GPS with accuracy of 1:100000
Regional Station: Control point at a distance of 40 k.m. average with a minimum 24 hour
observation with GPS at a accuracy of 1: 50000
The primary control points of the SOI Should have been post processed with the precise
ephemeris adjusted with the help of precise engineering soft ware (eg. Berenese s/w ) to the
ITRF co-ordinate system or with a consultation of Survey of India . All the primary and
secondary control points of districts should be connected to base and regional station of the
SOI as created above, to ensure connection to the National Framework.
Vertical Datum: MSL, i.e. mean Sea Level. The precision Bench Mark of the SOI should
be used as primary vertical control
1. Primary Control Points:
Horizontal
i. What kind of places: In protected areas like premises of permanent government
offices etc. The selected site should be open and clear to sky with acute angle of 15
degree. High tension power lines, transformers, electric substations ,microwave
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