137MHz / NOAA Weather Reception?

[Brian Reay]

An acquaintance (who isn't licensed) asked me about receiving weather
sat pictures from satellites.

I've done this in the past, some years back, but not recently, so I'm
broadly up to speed with the techniques and I've Googled the current
methods etc.- using cheap TV tuners seems popular.

However, I seem to recall that the 'old' 137MHz based system was being
phased out- this was the 'rumour' / grapevine chatter when I last did it
(some time back- perhaps 20+ years, I'm pretty sure it was before we
moved to this house I last dabbled in it).

Looking on the Internet, it seems that 137MHz is still active but I
can't see anything about when/if it is being phased out/stopped.

Obviously, I don't want to give advice on investing in kit if the 137MHz
system is near to 'end of life'.

Does anyone have any hard information, please?

[Gareth's Downstairs Computer]

Radio amateurs and men on the Clapham omnibus commit an offence by
deliberately receiving those transmissions.

ISTR that as radio amateurs we are licensed to receive other amateurs,
authorised broadcast, and standard frequency transmission.

This seeks to call into question the receiving Satnav transmissions!

[Brian Howie]

In message <oro18m$165$1...@dont-email.me>, Gareth's Downstairs Computer
<headstone255.but.n...@yahoo.com> writes

It's legal.

<https://www.ofcom.org.uk/__data/assets/pdf_file/0027/89037/Guidance-on-R
eceive-Only-Radio-Scanners.pdf>

The services that can be listened to under the definition of general
reception are:
1. licensed broadcasting stations;
2. amateur and citizens' band radio transmissions; and
3. weather and navigation transmissions



Brian
--
Brian Howie

[mm0fmf]

On 12/10/2017 16:20, Gareth's Downstairs Computer wrote:
> Radio amateurs and men on the Clapham omnibus commit an offence by
> deliberately receiving those transmissions.

Wrong.

Weather and navigation services are specifically included in the list of
what can be legally received in the UK.

[lordgnome]

On 12/10/2017 16:49, Brian Howie wrote:

>
> <https://www.ofcom.org.uk/__data/assets/pdf_file/0027/89037/Guidance-on-R
> eceive-Only-Radio-Scanners.pdf>
>
> The services that can be listened to under the definition of general
> reception are:
> 1.   licensed broadcasting stations;
> 2.   amateur and citizens' band radio transmissions; and
> 3.   weather and navigation transmissions
>
>
>
> Brian

I suppose you might include a 'good-will' legality from the RAF too,
since they are glad to supply details of the traffic control frequencies
of RAF Valley to enthusiasts!

[Jerry Stuckle]

Hi, Brian,

I don't know for sure and don't want to give you bad information.
However, I do have a contact at the local National Weather Service
office. I just dropped a note to him to see if he has any information.

I don't know when he'll get back to me; forecasters here don't have 8-5
jobs. But I'll let you know what he says when he does reply.

--
==================
Remove the "x" from my email address
Jerry, AI0K
jstu...@attglobal.net
==================

[Roger Hayter]

I suppose, at a stretch, ATC could be included in navigation services.
And no-one seems to have gone after the many receiving messages from
aircraft transponders. Perhaps the remaining prohibitions could be
withdrawn on human rights grounds, and replaced by a prohibition on
deliberate decryption, since I don't imagine anything confidential is
sent unencrypted nowadays.


--

Roger Hayter

[David Taylor]

On 12/10/2017 14:01, Brian Reay wrote:

The best place to ask would be the GEO-Subscribers Yahoo group:

http://groups.yahoo.com/group/GEO-Subscribers/info

The 137 MHz signals are still active with APT (similar to WEFAX) from
NOAA-15, NOAA-18 and NOAA-19, but these are the last of the APT line.
Russia now has digital transmitting satellites on 137 MHz, providing
about ten times the area resolution (1.1 km linear) and three channels
rather than two. The problem (in the UK) can be pager interference,
just as I found with "modern" rigs on 145 MHz.

http://www.satsignal.eu/Radio/2m-filter.html

At £10 for a DVB-T dongle, free software and perhaps a home-made QFH or
turnstile antenna it's not expensive, and it's educational - perhaps an
introduction to SDR?
--
Cheers,
David GM8ARV
Web: http://www.satsignal.eu

[Jeefaw K. Effkay]

But you would need the permission of the driver or conductor, before establishing any kind of amateur radio station aboard the Clapham Omnibus.

[lordgnome]

On 13/10/2017 07:48, Jeff wrote:

>>
>
> Many years ago when I was a member of the Remote Imaging Group there was
> a form the at you could fill in and return to, i think if I remember
> correctly, the Met Office, to gain permission to receive Wx images from
> satellites.
>
> Things may have changed though.
>
> Jeff

I suspect that in reality, nobody gives a flying fig about what people
listen to, or even did in the past. The exception perhaps being if you
monitored the police for nefarious purposes!

[Brian Reay]

Thank you, I will pass that on.

I may even try it myself as well.

I used a 'crossed dipole' previously but it has long since been stripped
down and the bits re-used.

[Graham.]

On Fri, 13 Oct 2017 12:39:53 +0100, Jeff <je...@ukra.com> coalesced the
vapors of human experience into a viable and meaningful
comprehension...

>I forgot to add that not many people actually did fill in the paperwork.
>
>Jeff

Pipefinders' licence anyone?

--

Graham.
%Profound_observation%

[Jerry Stuckle]

On 10/12/2017 9:01 AM, Brian Reay wrote:

Brian,

My friend didn't know the frequencies but he did have a direction. The
NOAA website for the GOES satellites is
http://www.ospo.noaa.gov/Operations/GOES/index.html. Although the
frequencies aren't on that page, your friend should be able to use the
"Contact" link to ask them.

I haven't dealt with this specific group before, but I've found previous
contacts with NOAA have shown them to be very helpful and forthcoming
with their information.

[Brian Reay]

Long 'gone' but there is a permit to cover searching beaches- as I
recall between high and low water. You don't need it to use a metal
detector elsewhere.

Like several other permits/licences which were either a formality (ie
you paid a nominal fee and it was issued), the old 'pipe finder' licence
went years ago.

The reception of weather images from satellites falls into this group-
it has needed a licence for years.

Even the permit I mention relating to beaches and metal detectors is
more about permission to search than the equipment licensing side.

[Brian Reay]

Thank you and everyone else who has provided helpful input. I will pass
it on to my acquaintance.

As an aside, I had a listen on 137.1 this afternoon, having looked at
the predictions for the few NOAAs still active using GPredict. Even with
just a broadband 'scanner' antenna hooked up to my IC-R7100 on WFM, I
could hear a respectable signal for perhaps 50% of the pass.

[Roger Hayter]

Looking at:

http://noaasis.noaa.gov/NOAASIS/ml/future.html

which seems to be a work in progress, with many broken links to the
details, the next system doesn't seem to be scheduled to come into
operation until after 2021. It will have a lower resolution service
like the current VHF one, but there is no statement I can find as to
whether it will be on 137MHz. In any case, it seems likely the present
service will continue at least until 2021. Though it might be
different if one or more satellites fail. Please let us know if anyone
gets a more definitive answer.




--

Roger Hayter

[Brian Reay]

The conclusion I had arrived at is that no 'they' wanted to end the
'old' NOAA service (there only seem to be a few active satellites, while
my memory may be playing tricks, I was sure there used to be a pretty
steady 'stream' of passes 20 years back), but couldn't quite turn things
off or even agree when to do so. Rather like disposing of a car you've
owned for years- you know it makes sense to replace it, you like the new
one, but the old one is 'comfortable'.

Something similar happened with various old Radio Navigation aids as GPS
gradually took over.

[mm0fmf]

On 14/10/2017 00:20, Roger Hayter wrote:

That page linked says the low rate data broadcast downlink for the new
Polar orbiting sats will be L-band and the high data rate broadcast
downlink will be X band. It also gives the convolution coding rate and
the Reed Solomon block coding rates.

L-band downlinks for fast moving satellites are relatively simple to
make. Patch antennas or QFHs can be home brewed for non-steered
antennas. The same kind antennas work FB for GPS or Iridium downlinks
now. I don't know or have experience of whether such omni antennas would
be viable for the X band downlinks. Maybe. Or it depends.

[David Taylor]

On 14/10/2017 06:48, Brian Reay wrote:
[]> The conclusion I had arrived at is that no 'they' wanted to end the

> 'old' NOAA service (there only seem to be a few active satellites, while
> my memory may be playing tricks, I was sure there used to be a pretty
> steady 'stream' of passes 20 years back), but couldn't quite turn things
> off or even agree when to do so. Rather like disposing of a car you've
> owned for years- you know it makes sense to replace it, you like the new
> one, but the old one is 'comfortable'.
>
> Something similar happened with various old Radio Navigation aids as GPS
> gradually took over.

There is an issue over providing weather data for maritime use, and
possibly in other remote areas not yet served by the Internet. The VHF
signals with omni-directional receive antennas were very good for that.
The satellites which are now transmitting are the ones which have not
yet failed.

As far as I know, there are no plans for a follow-up VHF service, only
for an L-band one (and that may be in doubt) which requires tracking
antennas for direct reception. The necessary meteorological information
may be available over satellite phone (for those lone yachtsmen and
yachtswomen and other small boats out there). Direct reception may
require tracking X-band dishes, out of the range of many small users.

Not to mention the amount of QRM on VHF these days from all the
switching power-supplies and the interference problems created!

--
Cheers,
David
Web: http://www.satsignal.eu

[Jerry Stuckle]

The VHF satellites never were designed for the average Joe to receive
directly (although the NWS never tried to stop it). AFAIK the NWS has
pretty much gone to geostationary satellites now and has little use for
the VHF ones. Additionally, those receiving the signal are mostly like
Brian's friend - hobbyists who like the challenge but don't have a real
need for the information (which I think was always the case). So there
is no real good justification for spending the money to replace them.

AFAIK, it's not available over satellite phone (and at $6 US/min. it
would be very expensive). And few boaters over here have satellite
phones. But weather reports are available on HF marine radios. Images
may be, also - I really don't know.

[David Taylor]

On 15/10/2017 04:06, Jerry Stuckle wrote:
[]

> The VHF satellites never were designed for the average Joe to receive
> directly (although the NWS never tried to stop it).  AFAIK the NWS has
> pretty much gone to geostationary satellites now and has little use for
> the VHF ones.  Additionally, those receiving the signal are mostly like
> Brian's friend - hobbyists who like the challenge but don't have a real
> need for the information (which I think was always the case).  So there
> is no real good justification for spending the money to replace them.
>
> AFAIK, it's not available over satellite phone (and at $6 US/min. it
> would be very expensive).  And few boaters over here have satellite
> phones.  But weather reports are available on HF marine radios.  Images
> may be, also - I really don't know.

The US were not the only providers of VHF satellites, even though they
have not chosen to continue to support users for future satellites.
Reception on small boats (and US warships) was and remains an important
feature (I have seen QFH antennas for WX reception on such military
vessels).

The resolution from geostationary satellites will never be the same as
that from satellites in a much lower orbit, and both the US, Russia,
China and Europe continue to launch both geostationary and polar
orbiting satellites - such as the EU Sentinel series:

http://www.copernicus.eu/main/sentinels

Information on atmospheric conditions is of great interest to radio
amateurs, and the GPS occultation data (grazing incidence) available
from several polar orbiting satellites could be helpful in determining
ionospheric conditions. It would be great to see more amateurs making
use of this freely available data.

[Jerry Stuckle]

On 10/15/2017 1:25 AM, David Taylor wrote:
> On 15/10/2017 04:06, Jerry Stuckle wrote:
> []
>> The VHF satellites never were designed for the average Joe to receive
>> directly (although the NWS never tried to stop it).  AFAIK the NWS has
>> pretty much gone to geostationary satellites now and has little use
>> for the VHF ones.  Additionally, those receiving the signal are mostly
>> like Brian's friend - hobbyists who like the challenge but don't have
>> a real need for the information (which I think was always the case).
>> So there is no real good justification for spending the money to
>> replace them.
>>
>> AFAIK, it's not available over satellite phone (and at $6 US/min. it
>> would be very expensive).  And few boaters over here have satellite
>> phones.  But weather reports are available on HF marine radios.
>> Images may be, also - I really don't know.
>
> The US were not the only providers of VHF satellites, even though they
> have not chosen to continue to support users for future satellites.
> Reception on small boats (and US warships) was and remains an important
> feature (I have seen QFH antennas for WX reception on such military
> vessels).
>

I realize that - and was addressing just the U.S. satellites, since that
was what the OP was asking about.

> The resolution from geostationary satellites will never be the same as
> that from satellites in a much lower orbit, and both the US, Russia,
> China and Europe continue to launch both geostationary and polar
> orbiting satellites - such as the EU Sentinel series:
>
>   http://www.copernicus.eu/main/sentinels
>

I never said it would be. I just said that the geosynchronous
satellites were good enough for most of NWS's work. NWS doesn't need
sub-meter resolution (and neither does NOAA for atmospheric readings).
The high resolution is needed for things like wave heights, point
infrared emissions, plant growth and similar.

> Information on atmospheric conditions is of great interest to radio
> amateurs, and the GPS occultation data (grazing incidence) available
> from several polar orbiting satellites could be helpful in determining
> ionospheric conditions.  It would be great to see more amateurs making
> use of this freely available data.
>

True, but that is not the purpose of NWS satellites. And raw data from
the polar-orbiting satellites is of limited use without significant
processing. Not to say hams can't do it - but I don't know of any
programs for processing that data.

[mm0fmf]

Are you sure an L-band solution would need a tracking antenna?

[Jerry Stuckle]

If it's not in geosynchronous orbit, it would. Even LEO would require
some type of tracking antennna. Even ham satellites in the 145 and 430
MHz bands require a tracking antenna.

[Jerry Stuckle]

On 10/16/2017 6:22 PM, mm0fmf wrote:

L band satellites have low power transmitters and an omnidirectional
antenna won't have enough gain (or directionality). Remember what their
purpose is - to furnish information to NOAA ground stations.

[David Taylor]

On 17/10/2017 02:11, Jerry Stuckle wrote:
[]

> L band satellites have low power transmitters and an omnidirectional
> antenna won't have enough gain (or directionality).  Remember what their
> purpose is - to furnish information to NOAA ground stations.

.. and to all "Direct Readout" users across the world. Hence the
regular Direct Readout Conferences.

[David Taylor]

On 16/10/2017 23:22, mm0fmf wrote:
[]

> Are you sure an L-band solution would need a tracking antenna?

At the power levels used, yes, they do.

--
73,

[mm0fmf]

On 17/10/2017 06:25, David Taylor wrote:
> On 16/10/2017 23:22, mm0fmf wrote:
> []
>> Are you sure an L-band solution would need a tracking antenna?
>
> At the power levels used, yes, they do.
>

I was surprised at first by that seeing how well my Iridium gear works
using a tiny ceramic patch antenna with the array of MEO satellites on
L-band. What I forgot was the bit rate for the proposed joint polar sats
is upto 4mbps and Iridium is a lot less.

[Jerry Stuckle]

On 10/17/2017 1:27 AM, David Taylor wrote:
> On 17/10/2017 02:11, Jerry Stuckle wrote:
> []
>> L band satellites have low power transmitters and an omnidirectional
>> antenna won't have enough gain (or directionality).  Remember what
>> their purpose is - to furnish information to NOAA ground stations.
>
> .. and to all "Direct Readout" users across the world.  Hence the
> regular Direct Readout Conferences.
>

The Direct Readout Conference is mainly for scientists, but it also
serves as a Public Relations event for non-scientists.

However, the PR is only a sidelight. The main purpose of the satellites
is for NOAA to get the information they need. A secondary purpose is to
provide the raw data to scientists for research purposes. NOAA just
doesn't discourage reception by the general public (they can't, by law
it is public information).