GSD-Mountain Map, raster format

Transcription

1 1(6) Date: Document version: Product description: GSD-Mountain Map, raster format

2 LANTMÄTERIET (6) List of content 1 General description Contents Geographic coverage Optional geographic delivery formats Coordinate system Quality statement Currency... Fel! Bokmärket är inte definierat. 3 Contents of delivery Delivery format File names... 5 Appendix 1: Coverage of GSD-Mountain Map, raster format... 6

3 LANTMÄTERIET (6) 1 General description GSD-Mountain Map in raster format can be used for presentation of the Mountain Map as a digital map image on a computer screen, for example as a cartographic background image. The raster images can also be used for producing value-added products and as input data for GIS. Use of the data is regulated through a licence agreement between the user and Lantmäteriet. 1.1 Contents The digital map image contains the same information as the printed maps 1: , with the exception of the reference grids. Each raster image comprises a file in which the GSD data has been merged to form a single 8-bit image. Edge matching was done when the 8-bit images were produced. 1.2 Geographic coverage GSD Mountain Map in raster format covers the same areas as the printed map series (see Appendix 1). 1.3 Optional geographic delivery formats Each raster image file contains data for one basic 50 x 50 km quad in the Swedish national map sheet line system. Unlike the printed maps, where deviations from the strict division into basic quads occur, all of the raster files conform to the basic 50 x 50 km format. In cases where the printed map does not cover the full extent of a quad the digital map image is filled out with white pixels 1.4 Coordinate system Plane coordinate system: SWEREF 99 TM Height system: RH 2000

4 LANTMÄTERIET (6) 2 Quality statement 2.1 Data collection method The raster images are generated from the database at a scale of 1: that is used to produce GSD-Road Map and GSD-Mountain Map at a scale of 1: Currency The stock of raster images is currently updated two times per year. 2.3 Positional accuracy The geometric accuracy of the raster images is the same as that of the printed map, which is approximately 20 metres. Where features have been generalized or moved for cartographic reasons, this general level of accuracy does not apply. The raster images are 5,000 x 5,000 pixels in size, which means that the resolution of the digital map image is 10 metres on the ground and 100 m at the map scale of 1:100, Completeness GSD-Mountain Map in raster format contains the same information as the printed map, with the exception of the reference grids. Some areas that are shown with a pattern in the printed map (e.g. marshland) are shown with an opaque colour in the raster images.

5 LANTMÄTERIET (6) 3 Contents of delivery 3.1 Delivery format The standard delivery format for GSD-Mountain Map, raster format is TIFF LZW compressed. Other optional formats are TIFF uncompressed, TIFF PackBits compressed, GIF, PCX, BMP uncompressed and BMP RLE compressed. The size of all raster images is 300 MB in the format TIFF lzw compressed, and 1.5 GB in TIFF uncompressed. 3.2 File names A file name is made up of three parts. The first part comprises two characters, which are always fj. The second part, comprising three characters, is the designation of the basic quad in the sheet line system, for example 20d. The extension identifies the image format. Example: fj20d.tif The following text files containing coordinate and related information are also included in deliveries: fjyyy.tfw fjyyy.tab fjyyy.ini fjyyy.hdr Coordinate information for ArcInfo and ArcView Coordinate information for MapInfo Coordinate information for AutoKa PC Metadata file

6 LANTMÄTERIET (6) Appendix 1: Coverage of GSD-Mountain Map, raster format Legend The quads represent the division into data files The thin grey lines within the quads are areas where there is Mountain Map data