Spectrum Software for Texas Gap Analysis -
Figure 1
Figure 1. TX-GAP Land COver
Analysis Process.
Figure explanation:
- MRLC hyperclustered TM scene (240 classes of
clusters/scene).
- Location (UTM coordinates) and description of the
vegetation observed in the field together with
ancillary information (vegetation maps,
literature and expert consultation) are used to
ground-truth the MRLC scene.
- Spectral patterning on the scene labeled with the
different types of vegetation present in the
area.
- Preliminary map by scene in rester format
(printed or digital copy is submitted for expert
review).
- Preliminary labeled scene exported from Spectrum
and saved as a binary file for further spatial
analysis and editing (GIS) processing.
- USGS digital line graphs are used to create a
mask of urban and other cultural features and
facilitate the refinement (edition) of
vegetation.
- Interpreted (labeled) scenes are run through a
model that adds and eliminates classes from
clusters. This model is developed from logical
arguments based upon a class being present or
eliminated from combinations of habitat
characteristics. This step checks the
interpretation process in step 2.
- An edited map with land cover refined by scene is
produced (vegetation descriptions from the field
are aggregated to the level of land cover classes
defined by the classification scheme selected).
- Another round of expert reviews of the models and
refined
products.
- The accuracy in predicting vegetation types is
assessed in the field based on a random sample of
points.
- A final land cover layer is produced in the GIS
(raster or vector format) and is ready to be
edge-matched (within the state) and processed
according to the standards required by the
National Gap Analysis Program.
Additional Notes:
Squares represent products (images, thematic coverages
or maps). Ovals represent processes performed to the
products.
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