Re: FAA To Finally Ditch Floppy Disks & Win-95

On Mon, 23 Jun 2025 16:43:35 GMT, Charlie Gibbs wrote:

On 2025-06-23, rbowman <bowman@montana.com> wrote:
 

Years ago Trimble was a big player when emergency services started
using AVL and they had their own format. Geocom, another player, sent
the coordinated in hex. It's been a long time but there was also a
magic number involved where x and y were the hex values.
>
*lat = (double) x * 5.729577957 * .0000001;
*lon = (double) y * 5.729577957 * .0000001;

 
That number looks suspiciously like the number of degrees in a radian,
divided by 10.

You're right. I was looking at source code I wrote about 20 years ago
without giving it much thought.

Unfortunately, now I'm thinking. I wonder what the raw GNSS data looks
like? There are a lot of GPS modules for microprocessors but afaik they
only spit out NMEA sentences. That's no fun.