Cadastral survey requires high accuracy over relatively short baselines.  We have implemented an RTK (Real Time Kinematic) system, based on three of Ashtech Z-Surveyor dual frequency, 12 channel, differential mode GPS receivers.  

The GPS receivers are joined via a VHF data link and in this mode, we regularly obtain sub-centimetre accuracy with observation times of less than 30 seconds.

For urban areas where the GPS coverage can be interrupted (with the need to re-gain phase-lock), we supplement observations with SOKKIA Total Stations.

For further information, please contact Geo Strategies at:
	Geo Strategies Ltd			Geo Strategies SA
	St John's Innovation Centre			Str G-ral V. Milea, 10A
	Cowley Road			Sibiu 550331
	Cambridge  CB4 0WS			Romania
	United Kingdom
	Tel:	+44 (0)1223 205080		Tel:	+40 (0)269 210832
	Fax:	+44 (0)1223 205081		Fax:	+40 (0)269 211165
	Email:	maps@geo-strategies.com		Email:	maps@geo.strategies.ro