Long range, low bitrate, small data transceiver unit for tel

[Tauno Voipio]

Heywood Jablome wrote:

"Tauno Voipio" <tauno.voipio@iki.fi.NOSPAM.invalid> wrote in message
news:wdaCe.209$SE1.75@read3.inet.fi...

Heywood Jablome wrote:

"Mark Harriss" <billy@blartco.co.uk> wrote in message


news:42d508c9$0$841$61c65585@uq-127creek-reader-03.brisbane.pipenetworks.com

.au...


Sounds like a cool experiment, there used to be a
CAA regulation ages ago about banning photos within a certain
angle of vertical, I'm not sure what the reason was but it
may pay to check if it still exists.


Regards
Mark Harriss


I cant for the life of me figure out why this rule would be there. I

would

ignore it anyway. It's a free country.

It is common in the aviation regulations in many countries.

Probably the reason is to prevent unauthorized map creation.

--

Tauno Voipio (commercial pilot & instructor)
tauno voipio (at) iki fi




I'd be interested in researching this further. Do you have a reference? I
find the rule preposterous, and highly insulting - even impeding on my- or
anyone elses- free will. Unauthorised maps? Who needs to authorise maps?

Start with the AIP (Aeronautical Information Publication) of your own
country.

In my country, Finland, the current aerial photographing regulations
are pretty liberal. The most important prohibited photo targets are
military installations and penitentiary units. When I started the
aerial photographing (a couple of tens of years ago) all negatives
had to be given in for inspection before copying. Also, the list
of prohibited targets was much longer.

AFAIK, the same targets are banned in all ICAO countries.

You may be surprised to notice that most maps are else accurate,
but there are things that are not mapped for public distribution.

--

Tauno Voipio
tauno voipio (at) iki fi

 

larwe@larwe.com wrote:

Who does one contact about buying bytes on a bird like this? I'd be
interested to find out what it costs to set up this sort of thing.

http://www.argosinc.com/

A general search on argos satellite applications will yield lots of
results.

EXTREMELY interesting, thanks for the link! One transmission a day on a
floating platform is about $77 per month, which gives you position data
plus 256 bits of telemetry.

There is a clause in there about not being able to get bird time if
there is a commercial equivalent to Argos, though. I wonder what
commercial equivalents there are... hmm, more research necessary.

Another low bitrate satellite service that is available worldwide is
Inmarsat D+. This provides bi-directional communication to small
mobile terminals most places more that 5 degrees away from the poles.
The smallest terminal available is the SAT-201 which is around 4.5
inches in diameter and 2 inches tall. More info from
http://www.satamatics.com

Ian

 

[Leo Patrick]

...
Another low bitrate satellite service that is available worldwide is
Inmarsat D+. This provides bi-directional communication to small
mobile terminals most places more that 5 degrees away from the poles.
The smallest terminal available is the SAT-201 which is around 4.5
inches in diameter and 2 inches tall. More info from
http://www.satamatics.com

Ian

Thank you for the link and information.
It is very intereting.
On their brochures
(http://support.satamatics.com/doc/portal/dl/bro0018/-/en/pdf/bro0018.pdf)
they say data transmission rate from terminal to satellite is ~10bits per
second and receive bitrate is 9 bits per second. They also say "By pressing
a panic button, the message transmission frequency can be dramatically
increased - for example, to every few minutes, to provide Search and Rescue
authorities with rapidly updating position reports." which is very good for
the applications given in their web site.

I'm afraid our applications requires almost continious communication between
ground station and balloon at 1200-19200 baud and that's why Satamatics's
terminals would not be appropriate for our application. But it is good for
me to learn the existance of such an alternatives. Thank you.

How they charge their services? Does cost defined by the amount of data
communicated ? Do you know how much it cost?

Thank you

Leo

 

Another low bitrate satellite service that is available worldwide is
Inmarsat D+. This provides bi-directional communication to small

Thanks - Magnus pointed me to Skywave's Inmarsat-D+ products, and that
kind of opened the funnel for me, I've been looking at all sorts of
options. They basically fall into three categories:

* Argos - restricted use (my application is probably eligible), 256
bits uplink only, low power requirements.

* Inmarsat D+ SMS - bidirectional telemetry and command information. It
would also be possible to use a prepaid [voice] satphone's SMS
capabilities to do the same thing, possibly cheaper (Skywave hasn't
returned my emails asking for pricing info).

* Other satellite data services (R-BGAN, Inmarsat mini-C, etc etc).
Would allow full uplink of image data as well as low-bandwidth
telemetry. I would never need to recover the vehicle if it had this fat
a satellite pipe.

The eye-opener for me is that all this stuff is really COTS and really
cheap (compared to what I thought it would cost, anyway); it looks as
if <$4k of equipment and as little as $0.79 per minute could get me a
full "high-bandwidth" bidirectional satcom system.