Re: Live video from balloon


Barry
 

A quick google of "fpv long range video transmitter" will find lots of info
on the topic. A number have received video from 10-15 miles out and check
out
http://fpvlab.com/forums/showthread.php?508-New-long-range-distance-record-%
26%238206%3B86-93km for an example of video received from 87 km away.

Lower frequencies offer better range than higher ones and 2.4ghz has more
than its share of wi-fi, blue tooth and similar signals so 1.2 ghz is what
many find the best to use. A HAB payload will almost always end up spinning
somewhat so to avoid antenna polarization issues it would be best to use
circular polarized Tx & Rx antennas. On aircraft a omni-directional antenna
must be used but the big advantage with HAB payloads where the Tx antenna
will always be pointing in the same direction (down) is that a higher gain
directional TX antenna can be used. The higher the gain the narrower the
signal beam is of course so just how much gain you decide to use depends on
how far away, horizontally, you want to be able to receive the signal. Our
group likes to stay fairly close to where the balloon is while tracking so
when we try this I figure a 90deg beam spread will be plenty. One could try
and use a much higher gain with even less beam spread, but one must also
allow for the fact that the payload may swing about some leaving the antenna
not always facing straight down. Anyway, do some research and have fun
trying which, IMO, is what it's all about.

Barry

-----Original Message-----
From: GPSL@... [mailto:GPSL@...] On Behalf Of
Michael Hojnowski kd2eat@... [GPSL]
Sent: Thursday, August 06, 2015 12:36 PM
To: Ballooning@...; GPSL list
Subject: Re: [GPSL] Live video from balloon

I've been curious about that, since the hardware is pretty much
commodity. The question is one of link budget. My FPV friends seem to
get about a mile of reception with their gear, even with clear LoS. Not
sure how a balloon that's 10-20 miles up, plus 20 downrange would come
through. I'd love to hear if folks have experience in that regard. I'm
sure some gain antennas would help, but I don't know the practical
limitations. I'm happy to do the homework if someone else hasn't
already. Just hopin' for a quick win! ;-p

Mike

On 8/6/2015 2:17 PM, Alan Adamson wrote:
Why don't you look at the stuff the RC guys are using on 2.4ghz for
FPV (first person view), doing that you can record it on the ground as
well and save the weight of the recording device.

There are even *overlays* that can overlay the position, speed,
heading, time, etc on the video

And they have done quite a bit around antenna systems, including even
direction tracking systems.

Alan


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