Location-Based Scanning (GPS)
(also see Population Area Centerpoint)
If you connect a GPS unit to the scanner, it can automatically enable/disable systems based on the geographic information you provide:
* Latitude (center of the range)
* Longitude (center of the range)
* Range (radius of a circle around the Latitude/Longitude) which can be selected from .5/1/3/5/10/20/30/50 miles
Rather than center the lat/lon on the antenna site for the system and set the range to the receivable range for the system, it makes more sense to center these settings on the geopolitical center of the system, and bound the range to encircle that entity. That is, while I can technically hear the Arlington TRS from west Fort Worth, I donít really want to. Instead, Iíd set the lat/lon/range values to approximate a circle around the Arlington city limits so that I would not hear Arlington until I approached/entered Arlington.
Also, not all geopolitical areas are perfect circles. You can modify the shape of the system by entering multiple sites for the system (even though the system might have only one site) and use different location settings for each site. For example, stack two circles to make a tall, narrow scan area for the system.