VHFDX.INFO

This site has crossed my radar a few times recently, and I finally got back to it with some time to look at what all is available there. The first thing I had been looking for was propagation information for VHF, particularly 6 meters. Looking deeper, I find real-time DX contact spotting on auto-refreshing maps.

Multi-band composite QSO map example

This really is a lot of information on one map ..!.. Looking at each band individually helps understand what frequencies are working and to where. I also found real-time MUF maps that show Sporadic E-skip ‘hot-spots’. WoW !
Go check out the North America 6m map on http://www.vhfdx.info – I registered with the site so that I can submit contacts and contribute to the data collection. Makes another good example of crowd-sourced science. I’ll be using this more . . .
Try it, you might like it …

Thanks Gabriel (EA6VQ) – this is a wonderful site. Well done sir .!.
/;^)

WhiteStar Balloon Update

There is a new update on http://whitestarballoon.com today;

White Star Balloon's website

and Dan Bowen boldly explains some of the complications encountered on their first launch attempt. There is a lot more complexity here than most casual observers may expect. What you don’t see is how many little details DID work as expected. This ain’t a typical party balloon, you don’t just ‘Let it go.”…

We will keep watch for future updates, and expect to be listening on the downlink for the telemetry when you are ready to try again.

/;^)

WB8ELK 20mHF balloon launch today

This just in via the [Balloonatics] YahooGroup …

Doing another Science Fair flight this Saturday from the NSSTC building in Huntsville AL. We also plan to do a paper airplane challenge to see just how far they REALLY go (being assembled by the Makers Local 256 group who won the Hacker’s Spaces in Space high altitude balloon competition to take the cheapest photo from Near Space last Summer)…..upwards of 100 paper airplanes will be released from the stratosphere with serial numbers on them….watch out Germany!!!….most likely they will be landing in Georgia unless we get some that achieve a million to one glide ratio.

Saturday Feb 26th at 1:30 pm CST 34.73 -86.64
WB8ELK on 14.102 MHz USB (audio will be centered around 1700 Hz) Sequence as follows starting at the top of each minute: – CW altitude – DominoEX16 – ASCII RTTY 110 baud – Hellscreiber altitude.
This is the same format that will be used in the upcoming WhiteStar Balloon trans-Atlantic flight. Important NOTE: when using dl-FLdigi to decode….please select the WB8ELK2 payload instead of the usual WB8ELK payload as I’ve added a new telemetry field.  Landing zone is south of Dalton GA.
Streaming video for this Saturday afternoon’s launch will be on the BATC: www.batc.tv – Click on Member’s Streams then select WB8ELK and hit VIEW.
- Bill WB8ELK

Distributed telemetry collection

Tracking a long-duration high-altitude balloon is a different kinda problem.
For a typical ARHAB flight, we use standard APRS beacon packets on 144 MHz, which are collected from most anywhere and relayed to the APRS-IS database. A long-duration flight is often associated with a trans-oceanic attempt, and VHF APRS just won’t get it done. So, we turn to the HF digital modes and get help from multiple receivers scattered around the world. With enough volunteer listeners, someone’s location will have good conditions and can copy the position beacons. Thanks to a customized version of the FLdigi code (called dl-FLdigi) and a website called SpaceNear.US – there is now a new network for ingesting and processing this distributed telemetry collection.
(reference links at the end of this article)

Flight path, and multiple receivers

This map shows a recent test flight, where WB8ELK used Domino EX16 encoding on his telemetry packets using a 200 mWatt transmitter on 7.077 MHz. His GPS receiver/HF transmitter/battery pack totaled about 1 pound. The balloon had a deliberately slow ascent rate, to keep it aloft for a longer flight. The launch was late in the day to avoid any solar heating. This balloon package travelled thru the dark of night, and landed in the middle of an artillery shooting range at Fort Stewart just west of Savannah GA. The map above shows the locations of the various operators that were listening for the beacon transmissions, using the dl-FLdigi program, and the path of the full flight.

Without going into a lot of detail here, I’ll provide some links, and encourage you to participate in these flights. This program makes it really easy.
The more listeners we have, the more likely we can track the entire flight.
There are plans for a trans-Atlantic attempt in Jan 2011.
Stay tuned for future details . . . . .
/;^)

Links of relevance :
ARHAB = Amateur Radio High Altitude Balloons
APRS = Automatic Packet Reporting System
APRS-IS = APRS Information System (used a lot for vehicle tracking)
dl-FLdigi = customized program with special HAB mode (JamesCoxon)
fl-digi = linux/Windows program for soundcard modem communications
SpaceNear.US = tracking website
WB8ELK = a world-reknown pioneer in ARHAB sciences
WhiteStar = upcoming trans-Atlantic balloon attempt