Some automated and semi-automated tools for linear feature extraction in two and three dimensions

1. A system for three-dimensional vector extraction from remotely sensed imagery of the earth's surface, comprising:

a vector extraction engine stored and operating on a workstation computer;

wherein the vector extraction engine:

builds a cost raster;

builds a plurality of digital surface model rasters based at least in part on the cost raster;

combines the rasters to form a new three-dimensional cost raster;

identifies image features in at least one of the rasters;

computes instantaneous values for the identified features;

calculates a vector based at least in part on the instantaneous values; and

projects the vector onto the new three-dimensional raster.

2. A method for three-dimensional vector extraction from remotely sensed image data of the earth's surface, comprising the steps of:

building, using a vector extraction engine stored and operating on a workstation computer, a cost raster;

building a plurality of digital surface model rasters based at least in part on the cost raster; and

combining the rasters to form a new three-dimensional cost raster;

identifying, using a vector extraction engine stored and operating on a workstation computer, image features in at least one of the rasters;

computing instantaneous values for the identified features;

calculating a vector based at least in part on the instantaneous values; and

projecting the vector onto the three-dimensional raster.