Decoding Scan Listings

S-Pol IHOP_2002, Oklahoma Panhandle
May/Jun 2002

The scan listings provide a description of the radar antenna motion while sampling a 3-Dimensional portion of the atmosphere. To sample in 3-D, the antenna moves in both azimuth and elevation, with the most typical scanning involving holding one angle fixed for a period, while the other angle changes; then, the fixed angle is changed or incremented and the process repeats (an exception is the co-plane scan, where azimuth and elevation change simultaneously). The NCAR scan listings are grouped by scan volume representation, within which there are multiple sweeps. A sweep is defined as an antenna motion where one angle remains fixed and the other varies (in the case of the COP scan, the co-plane angle is the fixed angle for a sweep, with the azimuth and elevation changing according to a known formula).

The scan listings for this project were compiled from the real-time S-Pol data stream. Scan delineation for this data stream can be slightly different from the post-processed data stream, with the most significant differences being in the scan start/end times and start/end angles of the sweeps (times of a given scan/sweep may differ by one or two seconds and several tens of degrees).

Scanlists contain the following information:

First Line of a volume grouping

Second Line of a volume grouping

Third Line of a volume grouping

This line contains headings for the various columns that appear in the suceeding "scan" lines. Each scan line starts with the scan number (sequential, starting when tape recording was re-initiated), and the start/end of a single scan (or sweep).

Succeeding Lines of a volume grouping

One line per sweep or scan. Can be as many as 64 sweeps in a given volume grouping. Each line contains start and stop times, as well as all the information described by the heading line.

--- Bob Rilling --- / NCAR Atmospheric Technology Division
Created: Mon Nov 11 15:00:03 MST 2002
Last modified: