1. Improvement of classic georeference by GSB (NTv2) grids Gábor Timár, Gábor Molnár Dept. Of Geophysics and Space Sciences, Eötvös University, Budapest, Hungary Eötvös Loránd Tudományegyetem Geofizikai és Űrtudományi Tanszék 1117 Budapest, Pázmány Péter sétány 1/A Geo-spatial seminar, 24 April, 2015

7. 1.Scanned maps 2.Geodetic and cartographic metadata (in case of old maps: work in archives) 3.Definition of the corners by manual or semiautomatic method, giving their coordinates 4.Checking of the resulted georeferred mosaic 5.Publishing (geo-spatial, MAPIRE, charta1864) Classic method: 2nd Habsburg military survey

8. Archive work: research for the geodetic and cartographic metadata Classic method: 2nd Habsburg military survey

9. Metadata in GIS: Ellipsoids (semimajor axis, flattening...) Datums (ellipsoid and its location, orientation) Projections (type and parameters) (prime meridians) (length units) (angular units) +proj=cass +lon_0=2.33721 +lat_0=48.83611 +x_0=0 +y_0=0 +a=6372056 +f=0 +towgs84=11545,271,-19080,18.098,3.673,14.292,1.0001228 +units=m +no_defs

10. Classic method: 2nd Habsburg military survey

11. „four-corner method” No coordinates indicated: sheet system is also a metadata Sheet label bears the georeference

12. Classic method: 2nd Habsburg military survey

14. Improved method: 1st Habsburg military survey 1.Scanned maps 2.Geodetic and cartographic metadata (in case of old maps: work in archives) 3.Definition of the corners by manual or semiautomatic method, giving their coordinates 4.Checking of the resulted georeferred mosaic 5.Publishing (geo-spatial, MAPIRE, charta1864) 1.Scanned maps 2.Virtual mosaic of the sheets 3.Defining of identical points (2-3 per sheet) by its image (mosaic) and WGS84 (Google) coordinates 4.Estimation of the parameters of an approximative projection (kilometer accuracy) AND 5.Definition of a correction grid (GSB, NTv2) 6.Kilometer-accuracy georeferred mosaic (using the approx. projection) 7.Refining the the georeference by GSB (200 m accuracy) 8.Publishing (geo-spatial, MAPIRE, charta1864)

15. Improved method: 1st Habsburg military survey

30. Thanks for your attention