GPS Status Screen

This screen is provided as a way to determine the status of the GPS receiver aboard your payload. In order for Balloon Track to fill out this form, it must have access to the $GPGSA string from your GPS receiver. Not all GPS units have this string available, but if you can include it in your packet telemetry you can open a window on what your GPS receiver is doing.

The PRNs are the satellite ID numbers. The fix mode indicates whether the GPS unit is in Manual Mode or Automatic. The fix type will display either NO FIX, or 2D or 3D. No fix usually means the GPS has lost lock and is reacquiring satellites. If you see a 2D indication,

then the altitude information is unreliable. 3D and you'll be getting good altitude data from the GPS unit. Altitude reporting may become unreliable depending on how your GPS was programmed. Some units don't report altitude above 64,000 feet (approximately). Others go up to 98,000 feet (approximately). In the old days, you know last century, you needed proper permission, to obtain GPS units with no altitude restrictions. Now I believe the Department of Defense has relented somewhat and has an either or restriction, either very high altitude reporting at slow speeds or higher speeds below 64K feet. Several folks have started incorporating these changes.

The Precision of Dilution numbers are indicative of the accuracy of the fix. The lower the number, the better the fix. Overall PDOP is a composite of the errors contained in the horizontal and vertical DOPs.

Press the reset button and all values will be erased.

Cancel exits this screen.