National Report of Sweden to the NKG General ... - Lantmäteriet

6marked in bedrock and theThe Swedish DGPS service EPOS is22RDS = Radio Data Systemapproximately 300 SWEREF pointsusing correction data from SWEPOS.EPOS is using the RDS 22 channel on theFM radio network for the distributionapproximate distance between them arearound 50 km. The observations lastedfor 2x24 hours, with a new set upand in July 2007 the operator of this between the sessions. They wereservice changed from Cartesia observed with antennas of DorneInformationsteknik AB to Teracom AB. Margolin T-type design and theBernese GPS software was used for theprocessing.1.5 The project RIX 95The large project RIX 95, whichinvolved GPS measurements ontriangulation stations and selected localcontrol points, was finalized in 2008. Itstarted already in 1995 and the workwas financed by a group of nationalagencies. The principal aim was toconnect local coordinate systems toboth the national reference frameSWEREF 99 and the old horizontalreference frame that SWEREF 99 hasreplaced, which is called RT 90.Another aim was to establish newpoints easily accessible for local GNSSmeasurements.The outcome of the project is 9029control points determined inSWEREF 99 and other existing national Figure 1.6: The 9029 control pointsreference frames, see Figure 1.6. The determined within the RIX 95 project thatoutcome also consists of transformation lasted 1995-2008.relations between these referenceframes as well as to local reference1.6 Implementation offrames used by the municipalities. Thetransformations are based on so-calledSWEREF 99direct projection (Engberg & Lilje,2006).By defining SWEREF 99 as an activereference frame we are exposed to relyon SWEPOS’ positioning services likeThe measurements were to large extentthe network RTK service. Allmade with standard equipment andalterations of equipment and softwarewith procedures for static observations.as well as movements at the stationsAround 300 of the points were howeverwill in the end affect the coordinates. Inmeasured in a way that coordinatesorder for the possibility to keep a checkwith very low uncertainty inon all these alterations, so-calledSWEREF 99 could be obtained. Theseconsolidation points have beenso-called SWEREF points are allintroduced (Engberg et al., 2010). The