Transformations and OSGM02 user guide - Leica Geosystems

More documents

Recommendations

Info

Where:1 the record number is a sequential number starting at 1 for the origin point (550 000, 800 000) and finishing at50451 for the north-east corner (800 000, 1 000 000).2 ETRS89, ITM projection, grid intersection easting coordinate in metres.3 ETRS89, ITM projection, grid intersection northing coordinate in metres.4 the height of the Geoid above the ETRS89 ellipsoid, in metres, at the intersection, that isETRS89 height – OSGM02 Geoid height = orthometric height above mean sea level.5 the Geoid datum flag is a number from 1 to 14, representing the geoid datum to which OSGM02 Geoid heightrelates, for example, this flag is 14 for Belfast, the orthometric height datum used in Northern Ireland.See table 1 (page 17), for details of other datum flag references.OSGM02 within the Republic of Ireland – format and layout of the dataWithin the Republic of Ireland OSGM02 is released as a single data file using a 1 km grid. This grid covers an area350 km east–west and 500 km north–south, the origin is offset by (400 000, 500 000) from the origin of the projectedETRS89 coordinates (see appendix B). As with the data for Great Britain and Northern Ireland, the area to which themodels are valid has been cookie cut to a polygon around the coastline and the border with Northern Ireland. Thismeans that any position more than 10 km offshore or 2 km over the border with Northern Ireland will have fields 4 and 5(see below) set to zero.It is strongly recommended that the transformation software be written to return an outside transformationboundary type error when a point outside this area is encountered.Transformations and OSGM02 user guide chapter 2v2.1 9/2002 © crown copyrightPage 15
Each record occupies a separate line with the south-west corner being the first record in the file. The format of eachrecord is indicated by the following table:Record no 1 Easting 2 (m) Northing 3 (m) OSGM02 GeoidHt 4 (m)1 400 000 500 0002 401 000 500 0003 402 000 500 000and so on and so on and so on351 750 000 500 000352 400 000 501 000353 401 000 501 000354 402 000 501 000355 403 000 501 000and so on and so on and so on175 848 747 000 1 000 000175 849 748 000 1 000 000175 850 749 000 1 000 000175 851 750 000 1 000 000Geoiddatum flag 5Where:1 the record number is a sequential number starting at 1 for the origin point (0,0) and finishing at 175 851 for thenorth-east corner (750 000, 1 000 000).2 ETRS89, ITM projection, grid intersection easting coordinate in metres.3 ETRS89, ITM projection, grid intersection northing coordinate in metres.Transformations and OSGM02 user guide chapter 2v2.1 9/2002 © crown copyrightPage 16
Page 2 and 3: PrefaceThis grid transformation sof
Page 4 and 5: Data copyrightUser guide copyrightT
Page 6 and 7: Appendix A Transforming ETRS89 GPS
Page 8 and 9: Orthometric heights in these system
Page 10 and 11: ETRS89 explainedBenefitsOrdnance Su
Page 12 and 13: Chapter 2Data overviewBasic princip
Page 14 and 15: Where:1 the record number is a sequ
Page 18 and 19: 4 the height of the Geoid above the
Page 20 and 21: For example, to find the record for
Page 22 and 23: Shifts for x, y are:se 0= east_shif
Page 24 and 25: The OSi/OSNI polynomial transformat
Page 26 and 27: The Ordnance Survey Geoid model: OS
Page 28 and 29: Chapter 4Quality statementCoverageO
Page 30 and 31: Appendix ATransforming ETRS89 GPS c
Page 32 and 33: The offset values are given by:dx =
Page 34 and 35: Appendix BConverting latitude and l
Page 36 and 37: ⎛ ⎛ 5 2 5 3 ⎞ ⎛2 21 3 ⎞
Page 38 and 39: Appendix CConverting easting and no
Page 40 and 41: Worked example using Airy 1830 elli
Page 42 and 43: Geoid modelA model of the level sur

Transformations and OSGM02 user guide - Leica Geosystems

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?