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Changing NZ Map Projections

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Geographic Coordinate System (WGS84) Geographic Coordinate System (WGS84) Tip of Christchurch Spit = 177 44 55.13 E, 43 33 43.81 S (long/lat) Tip of Christchurch Spit = 177 44 55.13 E, 43 33 43.81 S (long/lat) 1949?: New Zealand Yard Grid(s) 1949?: New Zealand Yard Grid(s) Separate North & South Island Grids, coordinates = yards Tip of Christchurch Spit = 610290 E, 552170 N SIYG (or NIYG?!) 1973: New Zealand Map Grid (NZMG) 1973: New Zealand Map Grid (NZMG) One Grid to rule them all, local datum NZGD1949, coordinates = meters. Tip of Christchurch Spit = 2489700 E, 5738300 N NZMG 2001: New Zealand Transverse Mercator (NZTM) 2001: New Zealand Transverse Mercator (NZTM) New technology (GPS & GIS), geocentric datum NZGD2000, coordinates = meters. Tip of Christchurch Spit = 1579660 E, 5176560 N NZTM

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Changing NZ Map Projections NZMG or NZTM?

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Changing NZ Map Projections mix n match NZGD1949 coordinates use a local datum, while the NZGD2000 coordinates use a geocentric datum. The two datums use different shaped ellipsoids. As a result, the NZGD49 and NZGD2000 coordinates for the same point differ by approximately 200 metres (approximately 10 metres in the east and 190 metres in the north directions). Coordinates can be converted from one datum to another based on transformation parameters derived from survey control stations which have coordinates on both datums ( more is better). NZGD1949 coordinates use a local datum, while the NZGD2000 coordinates use a geocentric datum. The two datums use different shaped ellipsoids. As a result, the NZGD49 and NZGD2000 coordinates for the same point differ by approximately 200 metres (approximately 10 metres in the east and 190 metres in the north directions). Coordinates can be converted from one datum to another based on transformation parameters derived from survey control stations which have coordinates on both datums ( more is better).

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Changing NZ Map Projections and Geographic Information Systems (GIS) NZ Census 1996 Deprivation Data Meshblock Boundaries (and road centerlines) in NZMG, overlain with address points in NZTM, from the LINZ Core Record System (CRS) (previously the Digital Cadastral Database DCDB). NZ Census 1996 Deprivation Data Meshblock Boundaries (and road centerlines) in NZMG, overlain with address points in NZTM, from the LINZ Core Record System (CRS) (previously the Digital Cadastral Database DCDB).

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GIS in Schools NEW ZEALAND Increasing number of schools use GIS for technology skills Hardware, software, data, and curriculum material is increasingly available Puts technology in a (spatial) context we can all relate to Google Earth, Wises Maps, Yellow pages, Harcourts Steep learning curve = time + support = GISMAPED

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GISMAPED http://www.gismaped.co.nz GISMAPED is a company providing professional development through high quality, practical, curriculum oriented workshops to teachers of Y5-13 Social Studies, History, Geography and Science, and to schools involved in the GLOBE programme. GISMAPED is a company providing professional development through high quality, practical, curriculum oriented workshops to teachers of Y5-13 Social Studies, History, Geography and Science, and to schools involved in the GLOBE programme. Site includes details of upcoming Workshops, access to resources, links to other related sites and information regarding qualifying for the Eagle Technology GIS In schools programme. Site includes details of upcoming Workshops, access to resources, links to other related sites and information regarding qualifying for the Eagle Technology GIS In schools programme. Anne Olsen anne@gismaped.co.nz or Stephanie Eddy stephanie@gismaped.co.nz Anne Olsen anne@gismaped.co.nz or Stephanie Eddy stephanie@gismaped.co.nz

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References Changing NZ Map Projections Land Information New Zealand: http://www.linz.govt.nz Land Information New Zealand: http://www.linz.govt.nzhttp://www.linz.govt.nz > Survey System> Geodetic Information> Projections & Datums ~/docs/surveysystem/survey-publication/witwaw.pdf ~/docs/surveysystem/survey-publication/witwaw.pdf Ollivier & Co: http://www.ollivier.co.nz Ollivier & Co: http://www.ollivier.co.nzhttp://www.ollivier.co.nz ~/projection/faq.shtm ~/projection/faq.shtm GIS in Schools GISMAPED: http://www.gismaped.co.nz http://www.gismaped.co.nz ~support, curriculum material ~support, curriculum material Eagle Technology (NZ): http://egis.eagle.co.nz/schools http://egis.eagle.co.nz/schools ~ FAQ, list server/email list, sponsorship deals might be dated. Environmental Systems Research Institute (ArcGIS ArcView/Arcinfo): http://www.esri.com http://www.esri.com ~virtual campus, online help ~virtual campus, online help UC GEOG: http://www.geog.canterbury.ac.nz/links http://www.geog.canterbury.ac.nz/links ~facilities for teacher workshops, and maybe school visits?