Change Detection

The landscape changes continually as a result of human activity and natural forces. These changes can have impaction ecosystem management, community planning and development, and property revenue assessments. Unlike many location based service companies Sanborn visually locates these areas of change in vast geographic datasets can be much like looking for a needle in a haystack.

To eliminate the time and expense of visually searching data for changed features, advanced Sanborn imagery analysis and processing techniques can be applied to multi-date imagery sets to “highlight” areas where change has occurred, enabling users to locate areas of change quickly and efficiently.

Change Observed Detail
Road Surface Area Road widening or new road
Road Surface Type Paving / road resurfacing
Forest Change in vegetation
Shrub Cover Change in low-growth vegetation
Vegetation Type Forested area, change of tree types
Buildings 
(no capture of features < 2,000 sq.ft.)
New structures vs no structures
Water Large change in rivers, lakes, ponds, pools
Agriculture Change in areas planted / crops planted
Land Use Undeveloped land to developed land
Change in Number of Objects Addition or removal of manmade objects

Conditions and Requirements
  • Price catalog is subject to change
  • Order acceptance subject to Sanborn approval
  • Source imagery must be a minimum of one meter (or better) resolution
  • Three-band (for best results, four-band imagery preferred) from multiple years in the same projection and covering the same geographic area
  • Minimum geography of 50 square miles
  • Please note: this process is designed to flag any change and in some cases variables (leaf-on vs. leaf-off), alternate sun angle (shadows), and differences in flight direction during collection, may cause detection. However, the product is designed on the premise that over classifying change---even if false positives exist---is preferable to missing change altogether.

Deliverables
  • Heat map (raster)
  • Categories tagged in vector format (available at additional cost)
  • All products provided as a single file (mosaic) unless file size exceeds limitations