WARN Algorithm

Remapping

WARN products are not stored in Cartesian format, so there is no remapping required. The output projection specified in the COMP configuration determines the default display location and range when the composited WARN product is displayed.

Overlapping

The key to combining WARN products is determining which of the input centroids are really the same feature, and which are different. We do this with the adjustable Centroid Distance specified in the Product Configuration Menu.

For WARN products, this field replaces the Output Smoother field used for other products.

The composite is started by copying the highest priority input. Then all the other inputs are looped through in priority order. Each new centroid is compared with all the centroids in the composite being assembled. If the center of a new centroid is within the centroid distance of the ellipse of a composite centroid, then they are treated as overlapped in the combination algorithm below.

Combining

The choices for combining algorithms in the Product Configuration Menu (see Configuring COMP) are different for WARN:

• OR Max

  The output contains a centroid for each centroid in any of the inputs. If 2 centroids overlap, then the maximum strength centroid is kept.

• OR Avg

  The output contains a centroid for each centroid in any of the inputs. If 2 centroids overlap, then the centroids are averaged together.

• AND Max

  The output contains a centroid only if all the inputs have a centroid at that location. The maximum strength centroid is used.

• AND Avg

  The output contains a centroid only if all the inputs have a centroid at that location. The average value centroid is used.