Topographic Maps & Nautical Charts

LAND INFO has topographic map coverage of over 237 countries. Our maps are available in a variety of digital formats, scales, resolution, and projections and are fully georeferenced and formatted for all GIS/GPS applications.

For detailed country coverage information please access the LAND INFO Geodata Catalog or contact us for a representative to assist you in your research.


Geo-referencing
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Not only can LAND INFO supply you with digital topographic maps we can supply you with all of your geo-referencing needs. To make our products more user-friendly we can process the map to a projection and datum of your specification.

Geo-referenceing is established by correlating the relationship between an image (row, column) coordinate system and a map (x,y) coordinate system, yielding a digital topographic map opening in GIS software in precise geographic location.

Control points selected from paper map Collars removed during processing

16 Control points selected from paper map

Collars removed during processing.



File Format
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DRGs (Digital Raster Graphics) are typically supplied as GeoTiffs however numerous options are available:
• GeoTiff
• Tiff World .tif with .tfw
• ADRG
• CADRG
• NITF
• ER Mapper .ecw
• LizardTech MrSID .sid
• JPG2000 .jp2
• Idrisi .rst
• ERDAS Imagine .img



File Sizes
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The file sizes will vary according to the specified DPI, Color Table, physical size and density of the map.
Some examples of typical files sizes:
• 400 DPI / 8bit / 20" x 30" / 1:50,000 scale = 80Mb
• 250 DPI / 4bit / 20" x 30" / 1:24,000 scale = 15Mb



Delivery Options
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LAND INFO provides several different delivery options:
• FTP
• CD-ROM
• DVD-ROM
• USB flash drive
• External hard drive (USB 2.0/USB 3.0/FireWire 400/FireWire 800/eSata)



Quality Control
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Each topographic map goes through a series of quality control steps to ensure you are provided with the highest quality GIS data for each project. Three steps we use to achieve the highest quality are:

  • The raw topographic map is checked against the paper topographic map to verify an accurate digital representation.
  • The processed topographic map is carefully inspected to assure that the topographic map is properly
    geo-referenced.
  • The four edges of the processed topographic map are compared to adjoining topographic maps to confirm
    proper alignment.

Map Scales

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Depending upon the printing source of the topographic maps, there are a variety of scales available for any given area of the earth. The following are some of the typical scales for both domestic and international topographic maps.

US Topographic Maps
1:24,000
1:25,000
1:63,360
1:100,000
1:250,000
1:500,000
International Topographic Maps
1:10,000
1:20,000
1:25,000
1:50,000
1:100,000
1:200,000
1:250,000
1:500,000
1:1,000,000
Global Nautical Charts
1:10,000 - 1:10,000,000