Date   

Re: GOMS3 support in the MSG Data Manager beta

Ernst Lobsiger
 

On Wed, May 12, 2021 at 08:37 AM, David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺 wrote:
Let me find the 0330 - looks like there's an offset - at a very quick glance.

David
David,

The offset of the visual channel is only a couple of times per day. The rest looks fine.
My worst offset so far was yesterday 20210511 03:30 (see image some posts back)

Cheers,
Ernst.


Re: GOMS3 support in the MSG Data Manager beta

Hugo
 

Ernst,

There was an overlay offset of channel VIS 0.9 at 3:30 and at 8:30 ....

grts,

Hugo


Re: GOMS3 support in the MSG Data Manager beta

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 12/05/2021 12:03, Ernst Lobsiger via groups.io wrote:
Dear All
I still struggle then and when with GOMS3. Satpy uses channels 0.9um and 10.7um
to produce an "overview" composite. Sometimes the 09um channel looks completely
offset from where it should be. To make sure that this is not a PyTROLL/Satpy issue:
Could users with MSG Data Manager, that still have the data of the images attached,
confirm that they see the same problem (if channels 0.9 and 10.7 are used)? Thanks!
Regards,
Ernst
Let me find the 0330 - looks like there's an offset - at a very quick glance.

David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv


Re: GOMS3 support in the MSG Data Manager beta

Hugo
 

Hi Ernst,

I can confirm that the VIS 0.9 channel of 8:30 is completely offset. The IR 3.8 is not offset but looks strange (always).
The VIS 0.9 image of 9:00 is again ok, so it's not a PyTroll problem.
I used of course EUMETCastView :)

grts,

Hugo


Re: GOMS3 support in the MSG Data Manager beta

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 12/05/2021 12:03, Ernst Lobsiger via groups.io wrote:
Dear All
I still struggle then and when with GOMS3. Satpy uses channels 0.9um and 10.7um
to produce an "overview" composite. Sometimes the 09um channel looks completely
offset from where it should be. To make sure that this is not a PyTROLL/Satpy issue:
Could users with MSG Data Manager, that still have the data of the images attached,
confirm that they see the same problem (if channels 0.9 and 10.7 are used)? Thanks!
Regards,
Ernst
Alignment looks OK here at a quick look - not tried overlaying those particular images yet. Quick test with GeoSatSignal, it's fine.

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv


Re: GOMS3 support in the MSG Data Manager beta

Ernst Lobsiger
 

Hi Graham

Yes your Satpy works the same my Satpy does. The question was whether we see the same thing with David's MSG Data Manager.

a) If MSG Data Manager (using channels 0.9 and 10.8) sees the same, then Roshydromet has a data problem.
b) If MSG Data Manager (using channels 0.9 and 10.7) sees no channel offset, then David might explain how the
    channel data is geographically located on the globe. There could be a difference compared to PyTROLL/Satpy.

Regards,
Ernst


Re: GOMS3 support in the MSG Data Manager beta

Graham Woolf
 

Hi Ernst

Here are my images - they appear to be the same as yours

However if you look at my 0700 image today that appears to be OK

Regards

Graham


Re: GOMS3 support in the MSG Data Manager beta

Ernst Lobsiger
 

Dear All

I still struggle then and when with GOMS3. Satpy uses channels 0.9um and 10.7um
to produce an "overview" composite. Sometimes the 09um channel looks completely
offset from where it should be. To make sure that this is not a PyTROLL/Satpy issue:
Could users with MSG Data Manager, that still have the data of the images attached,
confirm that they see the same problem (if channels 0.9 and 10.7 are used)? Thanks!

Regards,
Ernst


Re: TP 1 SNR reduction.

geojohnt@...
 

Ian and All,

I see from David's graphs that many users saw a step increase in SNR/LM at 12:00 UTC to day.

I continued my check on the Hotbird EUMETCast dissemination today moving the dish a bit further away from the fir tree than yesterday but I couldn't get an increase in my SNR.

The Hotbird transponder was turned off - well, the data stopped at 17:20:49 UTC according to the TC logs - and my SR1 was showing no lock when I had a look at 19:00 BST after watching the news.
So it was time to physically shift the dish back to its original position, realign it and reconfigure the SR1.
And I was pleased to see the Eutelsat 10 A EUMETCast signal had increased whilst I was on the other satellite.

Regards,
John.

+++++++++++++++++++++++++

My guess is that this signal issue is related to the Hotbird 13 degree

test which is due to complete about 14.00 UTC. In fact I have just
checked and the signal level appears to be increasing again, although I
will need better weather to completely confirm.

Regards
Ian.


-----Original Message-----
From: Ian Deans via groups.io <iandeans142@...>
To: MSG-1@groups.io
Sent: Fri, 7 May 2021 14:11
Subject: Re: [MSG-1] TP 1 SNR reduction.



On 07/05/2021 14:01, Douglas Deans via groups.io wrote:
> On 07/05/2021 13:44, David J Taylor GM8ARV 🏴 🇪🇺 via groups.io wrote:
>> On 06/05/2021 15:25, geojohnt via groups.io wrote:
>>> Hello All,
>>>
>>> I see from my own readings and David's across Europe signal graphs
>>> that most of us have seen a step drop in SNR/LM at 13:00 UTC today.
>>> My SNR is down from 13.5 this morning to around 12.5 dB with some
>>> cloud now.
>>>
>>> Regards,
>>> John Tellick.
>>
>> Folks,
>>
>> I headlined this in my daily report to EUMETSAT.  Previous responses
>> have suggested that as long as the signal is above the minimum agreed
>> level there's no need for action (by EUMETSAT).  They are in the hands
>> of their service provider, of course, they don't run the uplink
>> themselves.
>>
>> Cheers,
>> David
> ============================================================================
>
>
> Thanks David and I do agree. Nevertheless up here where the signal is
> more marginal it is annoying that there is an additional 1dB (which I
> lost yesterday) available. We know the back-up station can provide good
> improvements for example.
>
> Regards,
> Douglas.

===========================================================================







Re: TP 1 SNR reduction.

Ian Deans
 

On 07/05/2021 14:01, Douglas Deans via groups.io wrote:
On 07/05/2021 13:44, David J Taylor GM8ARV 🏴 🇪🇺 via groups.io wrote:
On 06/05/2021 15:25, geojohnt via groups.io wrote:
Hello All,

I see from my own readings and David's across Europe signal graphs that most of us have seen a step drop in SNR/LM at 13:00 UTC today.
My SNR is down from 13.5 this morning to around 12.5 dB with some cloud now.

Regards,
John Tellick.
Folks,

I headlined this in my daily report to EUMETSAT.  Previous responses have suggested that as long as the signal is above the minimum agreed level there's no need for action (by EUMETSAT).  They are in the hands of their service provider, of course, they don't run the uplink themselves.

Cheers,
David
============================================================================ Thanks David and I do agree. Nevertheless up here where the signal is more marginal it is annoying that there is an additional 1dB (which I lost yesterday) available. We know the back-up station can provide good improvements for example.
Regards,
Douglas.
===========================================================================

My guess is that this signal issue is related to the Hotbird 13 degree test which is due to complete about 14.00 UTC. In fact I have just checked and the signal level appears to be increasing again, although I will need better weather to completely confirm.

Regards
Ian.


Re: TP 1 SNR reduction.

James Brown
 

And even as you wrote - another small increase - possibly benefitting eastern stations more than western ones this time? From midday.

Cheers.

James

On 7 May 2021, at 13:47, David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺 via groups.io <david-taylor=blueyonder.co.uk@groups.io> wrote:

On 06/05/2021 15:25, geojohnt via groups.io wrote:
Hello All,
I see from my own readings and David's across Europe signal graphs that most of us have seen a step drop in SNR/LM at 13:00 UTC today.
My SNR is down from 13.5 this morning to around 12.5 dB with some cloud now.
Regards,
John Tellick.
Folks,

I headlined this in my daily report to EUMETSAT. Previous responses have suggested that as long as the signal is above the minimum agreed level there's no need for action (by EUMETSAT). They are in the hands of their service provider, of course, they don't run the uplink themselves.

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv





Re: TP 1 SNR reduction.

Douglas Deans
 

On 07/05/2021 13:44, David J Taylor GM8ARV 🏴 🇪🇺 via groups.io wrote:
On 06/05/2021 15:25, geojohnt via groups.io wrote:
Hello All,

I see from my own readings and David's across Europe signal graphs that most of us have seen a step drop in SNR/LM at 13:00 UTC today.
My SNR is down from 13.5 this morning to around 12.5 dB with some cloud now.

Regards,
John Tellick.
Folks,
I headlined this in my daily report to EUMETSAT.  Previous responses have suggested that as long as the signal is above the minimum agreed level there's no need for action (by EUMETSAT).  They are in the hands of their service provider, of course, they don't run the uplink themselves.
Cheers,
David
============================================================================

Thanks David and I do agree. Nevertheless up here where the signal is more marginal it is annoying that there is an additional 1dB (which I lost yesterday) available. We know the back-up station can provide good improvements for example.

Regards,
Douglas.


Re: TP 1 SNR reduction.

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 06/05/2021 15:25, geojohnt via groups.io wrote:
Hello All,
I see from my own readings and David's across Europe signal graphs that most of us have seen a step drop in SNR/LM at 13:00 UTC today.
My SNR is down from 13.5 this morning to around 12.5 dB with some cloud now.
Regards,
John Tellick.
Folks,

I headlined this in my daily report to EUMETSAT. Previous responses have suggested that as long as the signal is above the minimum agreed level there's no need for action (by EUMETSAT). They are in the hands of their service provider, of course, they don't run the uplink themselves.

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv


Re: daily cyclic signal change

geojohnt@...
 

Hello Nigel,

I would say that that the diurnal variation we see is more to do with the state of the troposphere and space weather than the figure of 8 movement of our satellites.
When the Sun is on 'our side of the planet' our polarised signals can become slightly twisted as they pass through the various 'excited layers.'

Commercial TV satellites are quite tightly controlled by the satellite operators - but of course their 'movement' is not that important for domestic satellite TV reception with 45 cm receiving dishes - more  important for the service uplinks to the satellite.

Just look at the inclination of MSG-1 and MSG-2 - though they are spin stabilised, not three axis.
They will take some tracking from the ground station control dishs.

On our GEO visits to EUMETSAT we went to the satellite ground station at Ursingen and standing under the giant Meteosat receive/control dishes, they would make a loud clunk every now and again as they tracked the slight movement of the satellite.

You are absolutely right, it's amazing how the geostationary satellite 'stay in the same place.'
One forgets(?) they are actually moving - as the Earth is. 

Regarding our 'dish alignment,' most of us use domestic satellite TV dishes which I would say in their original construction are impossible to align to 100% accuracy.
And as for the Triax 1 m dish - the less said about that, the better.

Several members have designed a sort of Vernier lever system to adjust both elevation and azimuth to very good accuracy.


Regards,
John




-----Original Message-----
From: nigel <nigel@...>
To: MSG-1@groups.io
Sent: Thu, 6 May 2021 8:48
Subject: Re: [MSG-1] daily cyclic signal change

Hi John,
Good to hear from you, also.
Thanks for your thoughts and yes, I am seeing a "diurnal variation" - i.e. the same pattern repeating each day, but I do not know if it is due to the earths rotation or the satellite describing a figure of 8 ( or 0 - thanks for the reminder of your animations, Ernst! ) about its nominal position.
I  hadn't really thought about what is required to keep a geostationary satellite fixed in position, in relation to a location on earth, when we are both spinning in space. My mind boggles at the maths involved, let alone the technology required. Harmut's comment about the saving in fuel really started me thinking !!
As for getting the alignment within 0.5 degree - I would think that must involve a very precise mounting arrangement - not possible with the bog standard commercial setup. I did plan to try and improve my dish's mounting and adjustment system, but that is still at "the design stage".
More googling and research is needed, I'm sure.
Regards
Nigel


On 05/05/2021 17:35, geojohnt via groups.io wrote:
Hello Nigel,

Good to hear from you again.

Firstly TP 1 has been 'doing something' in the last few days.
You will have seen that Ian and I reported a few days ago that our SNR has increased considerably - but it wasn't to last.
Back to normal a day or so later.
Though I did see another brief increase again yesterday afternoon.

By daily variation, do you mean at 'set' times/periods - your graphs appear to show this.
I too have a variation in SNR during the day - diurnal variation - due to that state of the atmosphere/troposphere.
I wrote an article about this for the GEO Quarterly a few years ago.

I always wondered about whether 'we' would see signal variations due to a satellite's figure of 8 movements but dismissed this as the movements were 'very small.'
However looking at EUMETSAT's dish off pointing graphs as posted by Ernst, you can lose 1 dB 'very easily' with an 0.5 degree dish error when using larger dishes.

Goodness, is it possibly to align a dish to 0.5 degree accuracy or less? 

Best wishes,
John.

 

_._,_._,_


EUMETCast Hotbird dissemination test.

geojohnt@...
 

Hello All,

Just a quick first test - swinging my dish further towards the neighbour's fir tree.
I must be right on the edge now.

Using a 1 m dish, Inverto quad Black Ultra LNB, skew adjusted and an SR1 I'm getting SNR 14.4 dB Power -23 dBm as shown by the SR1 Controller display.

I would have expected my SNR to be higher(?) since Hotbird 13 E's power output contour in my location is 5 dBW higher than Eutelsat 10A.

Regards,
John Tellick.



Re: TP 1 SNR reduction.

nigel
 

On 06/05/2021 17:29, Hartmut Schulla via groups.io wrote:

Hi!

Same here! Drop of approx. -1.2dB

day

Regards

Hartmut

 

Von: MSG-1@groups.io <MSG-1@groups.io> Im Auftrag von geojohnt via groups.io
Gesendet: Donnerstag, 6. Mai 2021 16:26
An: msg-1@groups.io
Betreff: [MSG-1] TP 1 SNR reduction.

 

Hello All,

 

I see from my own readings and David's across Europe signal graphs that most of us have seen a step drop in SNR/LM at 13:00 UTC today.

My SNR is down from 13.5 this morning to around 12.5 dB with some cloud now.

 

Regards,

John Tellick.

 

 

 

 


Re: TP 1 SNR reduction.

geojohnt@...
 

Hello Hartmut,

Yes.
My SNR is down at least 1 dB but there is a weather front going over at the moment.

I've reported this to EUMETSAT.

Regards,
John.




-----Original Message-----
From: Hartmut Schulla via groups.io <mail@...>
To: MSG-1@groups.io <MSG-1@groups.io>
Sent: Thu, 6 May 2021 15:29
Subject: Re: [MSG-1] TP 1 SNR reduction.

Hi!
Same here! Drop of approx. -1.2dB
day
Regards
Hartmut
 
Von: MSG-1@groups.io <MSG-1@groups.io> Im Auftrag von geojohnt via groups.io
Gesendet: Donnerstag, 6. Mai 2021 16:26
An: msg-1@groups.io
Betreff: [MSG-1] TP 1 SNR reduction.
 
Hello All,
 
I see from my own readings and David's across Europe signal graphs that most of us have seen a step drop in SNR/LM at 13:00 UTC today.
My SNR is down from 13.5 this morning to around 12.5 dB with some cloud now.
 
Regards,
John Tellick.
 
 
 
 


Re: TP 1 SNR reduction.

Hartmut Schulla
 

Hi!

Same here! Drop of approx. -1.2dB

day

Regards

Hartmut

 

Von: MSG-1@groups.io <MSG-1@groups.io> Im Auftrag von geojohnt via groups.io
Gesendet: Donnerstag, 6. Mai 2021 16:26
An: msg-1@groups.io
Betreff: [MSG-1] TP 1 SNR reduction.

 

Hello All,

 

I see from my own readings and David's across Europe signal graphs that most of us have seen a step drop in SNR/LM at 13:00 UTC today.

My SNR is down from 13.5 this morning to around 12.5 dB with some cloud now.

 

Regards,

John Tellick.

 

 

 

 


TP 1 SNR reduction.

geojohnt@...
 

Hello All,

I see from my own readings and David's across Europe signal graphs that most of us have seen a step drop in SNR/LM at 13:00 UTC today.
My SNR is down from 13.5 this morning to around 12.5 dB with some cloud now.

Regards,
John Tellick.





Re: SR1 changing receiving channel?

geojohnt@...
 

Hello Ernst,

Oh, of course, thanks.

It's just how to re-configure the SR1 - there seems to be no guide as to changing the set up - like 'do this, then this and then this.
If you see what I mean as the SR1 came setup for the current - original - EUMETCast configuration.

Regards,
John




-----Original Message-----
From: Ernst Lobsiger via groups.io <ernst.lobsiger@...>
To: MSG-1@groups.io
Sent: Wed, 5 May 2021 17:49
Subject: Re: [MSG-1] SR1 changing receiving channel?

On Wed, May 5, 2021 at 09:08 AM, <geojohnt@...> wrote:

Polarisation requires changing but the SR1 doesn't have a H/V 'switch' in configuration.
John,


polarisation is switched by LNB voltage (power) applied:

H = 18 Volt
V = 13 Volt

Ernst


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