Denton County ARES Projects

GRLevel3 APRS Placefile

To assist Net Control Station (NCS) operation in a severe weather event, I have written a script that will plot APRS users in GRLevel3. This is open to all radio amateurs operating with Denton County.

Spotters: Please add “!DCARES” to the comment text. “!SN!DCARES” will also work.

There are two GRLevel3 placefiles available to use: filtered and unfiltered.


  • 150km radius around city of Denton
  • All packets with location


  • 150km radius around city of Denton
  • Location packet
  • Tag “!DCARES” must be present in comment field (“!SN!DCARES” will work too!)


  1. Open GRLevel3
  2. Under the “Windows” menu at the top, check the “Show Placefile Manager” box
  3. Click the “Open” button in the Placefile Manager
  4. Copy these addresses into the prompt in GRLevel3:

Changing Text Color

If you wish to change the text color as it appears in GRLevel3, add the variables r, g, and b to the URL (as seen below). These variables associate with red, green, and blue respectively. The valid ranges are 0-255. With no variables specified, it will default to white.

…/aprs_placefile.php?filter=xyz&r=128&g=128&b=128 [this works for both filtered and unfiltered]

Manually Adding Stations to Filtered List

Unfortunately, I’m not going to publish this URL for all to use. If you’re an NCS and would like access to this URL, send me an email and I’ll pass it along.



  • Migrated backend service to systemd


  • Moved to DCARA VPS
  • Changed database architecture
    • All packets now stored in one table
    • Each flag has its own column in another table; index is callsign, columns are timestamps and various flags
    • Callsigns that have a valid flag (DCARES, SN, etc) flip true bit in respective flag column
  • Changed architecture of script and database for future flag additions (other areas maybe?)


  • Initial release

Leave a Reply

Your email address will not be published. Required fields are marked *