Thursday, May 27, 2010

APRS track export tool

Please try out the new data APRS export tool. There are no links to it from the web site yet. User account and login required. Feedback welcome, as usual!

It can export to KMZ (zip'ed KML + embedded symbol graphics in the same file, for Google Earth), CSV (opens up nicely in Excel, but seems to require some tricks in OpenOffice), JSON and XML (for the programmers out there).

This feature is aimed at people who wish to download their balloon's track afterwards, or their path to Dayton and back.

It's not aimed at people who wish to download the whole database, so it's rate limited quite heavily. Also, it's not an API. I'll probably set the limit to 3 downloads per day per user, although for the beta test, it's currently set to 10 downloads per day per user.

Map on info page, with symbols, and other small things

The info pages now have a little static map showing the station's position. I hope you like it this way. The static maps have also been upgraded to show proper APRS symbol graphics! For example:

Some of the pages now have an "add this" button which allows you to easily share the page on your favourite social networks.

The raw packet display was fixed to be really, really binary clean. It used to choke on some high binary values.

Weather packets with an unrealistic high or low temperature are now ignored.

Thursday, May 20, 2010

Ham::APRS::FAP 1.16 released

Version 1.16 of the APRS packet parser was uploaded to CPAN last night, and according to the first few CPAN tester reports it seems to be working as expected. Here's a list of changes:
  • Added a couple of test cases
  • Added an example script to parse a whole file of timestamped APRS-IS packets
  • Fixed peet WX packet parsing for Perl 5.8 and older, which don't support n! packing
  • Minor speedups by reducing amount of regular expressions, extra variables, reordering things to catch the most common case first, and tightening a loop
  • Put '' around hash key strings (style issue)
The main change was the Perl 5.8 wx parsing fix. I couldn't have noticed it without the CPAN testers and the unit tests included with the module, since I don't run on 5.8 myself any more.

Thursday, May 6, 2010

KP4AO Arecibo Observatory EME reception using a 10-element yagi

This is old news, but anyway... I've just forgotten to upload the videos from my iphone.

On Sunday, 24th of April, I received CW and JT65B transmissions from the Arecibo Observatory in Puerto Rico. Reflected via the moon (EME, Earth-Moon-Earth). Using a very small directional antenna - a 10-element yagi, a scanner-type receiver (Icom IC-R2500) and a small but good preamplifier at the antenna.

To get a good view of the moon we drove to the side of a nearby field with OH2GEK. He even tried to get a two-way contact with the Arecibo station using his TS-2000 and a longer yagi.

Here's a video of the KP4AO CW reception:

And here's one of the JT65B digital signals:

Problem and Solution

This, my friends, is a problem.

And here, my friends, arrives the solution:

Well packaged.

4 units of 1 terabytes each. After RAID10, that's a nice 2 TB of storage for

This is just for the backups. I'll need to get 4 more of these within a couple of months to upgrade the live servers.

Thanks go to an anonymous Finnish site user for the donation of 2 disks (and organizing delivery in 26 hours), and all other donors for the other two!

Wednesday, May 5, 2010

Ham::APRS::FAP 1.15 released

Version 1.15 of Ham::APRS::FAP, the APRS packet parser module used by, was uploaded to CPAN yesterday evening. It should appear on mirrors today. This update contains all the changes implemented since November 2009.

Like most of you know by now, the parser is released in Open Source terms (GPL or Artistic license, like most of Perl) so that others can freely use it to implement APRS systems. I believe it is the most complete APRS decoder available as open source.

Here's the change log:

1.14 Tue May 4 20:31:33 EEST 2010 - Hessu, OH7LZB
  • Fixed humidity parsing, h0 means 100%
  • Fixed peet bros $ULTW packet parsing, integers are signed (not unsigned), negative fahrenheit temperatures are now correctly parsed (and converted to Celsius)
  • Parse comment from end of weather reports - if it's short enough treat it as the wx station/software type string
  • Parse weather data sent after a compressed position
  • Parse snowfall from normal wx packet
  • Added test for positionless wx packets
  • Added position packet format in hash ('format' => 'compressed')
1.15 Tue May 4 20:44:31 EEST 2010 - Hessu, OH7LZB
  • Added a couple of missing tests and 'format' => 'nmea'