DWELL Algorithm: Composite in Time

DWELL is comprised of a product and composites successive images of a product in time. Moving targets show a "streak" on the display.

DWELL is similar to the photographic technique of leaving the camera shutter open while photographing a moving target. The background is fixed and the moving target shows a "blur" behind it.

Figure 1. DWELL Schematic Example

The DWELL product algorithm is a "time composite" of the input products. Because of this, the product that is generated by the DWELL algorithm is of the same type as the input product. For example, if we "dwell" a PPI product, a new PPI product is generated. The choices for the type of data that are displayed in the DWELL PPI product are:

  • Original input data

    For example, if a PPI of dBZ is used as input, then DWELL makes a time composite of dBZ.

    This is useful for showing where precipitation has fallen during the dwell time. When animated, the life cycle of growth, decay and motion of individual echoes can be easily seen.

  • Time

    The data points in the DWELL product are coded by their age from the time of the most recent product in the DWELL. The display shows a color coded time history of echoes.

Because DWELL products show the integrated time history of echoes, they are a useful alternative to the TRACK product.

In airborne target detection, DWELL is used to track and automatically warn about the presence of aircraft or migrating bird flocks.