Re: radar display

• To: Doug Lindholm <lind@xxxxxxxx>
• Subject: Re: radar display
• From: "From: Bill Hibbard <hibbard@xxxxxxxxxxxxxxxxx>" <billh@xxxxxxxxxxxxx>
• Date: Mon, 20 Dec 1999 16:55:54 -0600 (CST)

Hi Doug,

You can probably use the classes:

1. visad.bom.Radar2DCoordinateSystem - which is a
CoordinateSystem for (range, azimuth) with an Earth
(Latitude, Longitude) Reference, and with azimuth in
degrees and range in meters.

2. visad.bom.Radar3DCoordinateSystem - which is a
CoordinateSystem for (range, azimuth, elevation) with an
Earth (Latitude, Longitude, Altitude) Reference, and with
azimuth and elevation in degrees and range in meters.

Using these, your radar data are FlatFields woth MathType:

  ((range, azimuth, elevation) -> reflection)

where the RealTupleType (range, azimuth, elevation) is
constructed with a Radar3DCoordinateSystem, and the FlatField
has a Linear3DSet domain set (since presumably sampling is
linear and Cartesian in range, azimuth and elevation).

Then display this FlatField with ScalarMaps such as:

  Latitude -> YAxis
  Longitude -> ZAxis
  Altitude -> ZAxis
  reflection -> IsoContour

As James suggests, you may also divide your data into a
set of FlatFields, each at a constant elevation.  One way
to do this is with a Gridded3DSet with manifold dimension
= 2 (note visad.bom.RadarAdapter does this).  Then each
elevation looks like a curved cone (curved because
Radar3DCoordinateSystem takes into account the fact that
the curved Earth falls away from a flat radar beam.

Cheers,
Bill
----------------------------------------------------------
Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI  53706
hibbard@xxxxxxxxxxxxxxxxx  608-263-4427  fax: 608-263-6738
http://www.ssec.wisc.edu/~billh/vis.html

• References:
  • radar display
    • From: Doug Lindholm