Vector Feature Extraction from Topographic Maps,
Satellite Imagery & Aerial Photography

Digitizing features is one of the most time consuming and tedious aspect of compiling GIS data, but also one of the most vital ingredients in creating your GIS database. LAND INFO saves you from this grueling task and allows you to better invest your efforts in other areas.

LAND INFO extracts vector features from topographic maps, satellite imagery, and aerial photography. Topo maps are an ideal base for large-area coverage, and can optionally be updated with detailed coverage extracted from aerial or satellite imagery of select areas. Because topographic maps often include ground truthing they may supply detail above and beyond satellite imagery, as an example cultivated areas can clearly be distinguished in satellite imagery but topographic maps may show the specific crop being grown (on the other hand the satellite imagery is much more current than the topo map.)

Available layers, depending on map scale/publisher, include:

Each layer is output in a vector file format, enabling easy integration with original imagery, maps and other geo-data.
LAND INFO also offers vector feature extraction from satellite imagery. For more information, please Contact Us today.

Vector Generation

LAND INFO uses both automatic and manual methods of extraction. The automatic method uses pixel value interpretation software to trace a vector line over continuous pixels of certain color values. The manual method consists of heads-up/on-screen digitizing over a DRG (Digital Raster Graphic – geo-referenced color scan of a topographic map or nautical chart)

Once the vector features are extracted to line files, they can be attributed to your project specifications. This includes having a separate vector file for every vector feature or combining many vector features into one vector file with appropriate attribution. Specific attribution, such as codes and numeric representation, can be added to the vector files attribution table to easily ingest the data into specific applications.

File Format

• Esri .shp shapefile or .mdb GeoDatabase
• AutoCAD .dwg or .dxf
• MapInfo MIF/MID/TAB
• Microstation .dgn

(Note: If your desired output is not listed above we can easily convert to proprietary formats.)

Delivery Options

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

Vector Feature Extraction has several areas that need to be checked to assure a quality GIS Data product. This includes accurate digitization from the source material, built topology, and attribution accuracy.

1. The source material is used as a benchmark to ensure that all derived data is accurately captured.
2. All vector files are overlaid on top of their source material and visually inspected by trained technicians to assure that all features are captured accurately.
3. The attributes are verified against the source data and against any client data that is provided to ensure its smooth incorporation into client applications.