Wednesday, May 7, 2008

!DAO! support for greater precision

Tapio Sokura, OH2KKU, implemented the APRS precision and datum option (DAO) in the Ham::APRS::FAP parser last night. Looking at the IRC channel log, he started working on it at around 01:40 AM local time, and finished at 04:33 AM.

A few minutes ago I installed the new parser code on, so those of you transmitting uncompressed or mic-e packets with the DAO extension should now see the improved precision.

Compressed format packets have enough precision (around 1 foot) already, so DAO is not useful with it. properly decodes compressed packets (including speed and course), and compressed packets are the smallest ones (they help conserve valuable channel time on 144.39 and 144.800 MHz), so I would recommend using the compressed format instead of uncompressed or mic-e with DAO.

The only supported datum is still WGS84, no conversion from other datums specified by DAO is done.


Jeremy W. said...

What IRC network and channel do you hang out on? I'm a developer and into amateur radio/APRS and would love to lurk and learn.

Anonymous said...

More Balloon launch activities: This link has a schedule of recent and future launches with dates, locations frequencies, and more --

This morning's launches in Texas looked good (K5LSU-11 and W5GIX-11).

-Mark Rice
(previously N4CMB, now licensed as KK5MR)

Hessu said...

We hang on ircnet's channel #aprs. Currently only Finnish hams there, so the language is Finnish, too. It might switch to English (at least partially) if interesting English-speaking people would pop up.