brainwagon "There is much pleasure in useless knowledge." — Bertrand Russell

13Jan/080

Nice NOAA-17 pass today!

Jan 13, 2008, NOAA-17I got a pretty good recording of the NOAA17 pass today, and converted it with my software. Turned out very nice. You can see Catalina and San Clemente Island off the coast of California. One of my better ones to date.

Addendum: I didn't use my Radio Shack scanner for this, I used my little Yaesu VX-3R instead. I'm beginning to suspect it is a good deal more sensitive than the scanner, although it's really hard to tell.

Filed under: My Projects No Comments
13Jan/082

Plan 13, in Python

Well, I've made some headway on a project that I thought would be cool to write: porting G3RUH's Plan 13 Satellite Prediction algorithm to a more palateable language than BASIC. I chose python, and it appears to be mostly working. It reads in the TLE orbital elements (same ones I use in "predict" or "gpredict") and then allows you to create a bunch of satellite objects, and query their positions over time.

Here's a screendump of a simple test program that I was running this morning:

Monitoring Satellites Using Python Plan13

Satellites which are above the horizon are marked in bold. They are sorted by elevation. The datafields displayed are elevation, azimuth, latitude and longitude of the subsatellite point, velocity, the Doppler velocity, and the frequency of a signal Doppler shifted from 435.845Mhz (just a value I did to check, since I was using PolySat CP3 at the time, which has APRS telemetry downlinked on that frequency). The code requires some additional cleanup, and once I have it all ready to go and documented, I'll make it available. I think it will have a lot of uses.

13Jan/080

Grump! AO-51 down, command team on it.

Sigh. I was gonna work AO-51 this morning, but couldn't hear the downlink. I shifted to the digital downlink frequency, and could hear it was active. It appears the satellite is temporarily off line. From the amsat-bb mailing list:

AO-51 stopped transmitting and went into Boot Loader mode. The command team has reset the satellite and have the digital downlink up and running.

We will reload the satellite as quickly as possible.

73,
Gould, WA4SXM
AO-51 Command Team

Best of luck getting it back online, lads!

Filed under: Amateur Radio No Comments