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Re: Meteosat-5 problems?

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

--- In MSG-1@..., johnrigsec@a... wrote:
All,

I have just downloaded a direct WEFAX image from Meteosat-5 -
20:06. The signal was very strong and steady and the WEFAX image
perfect.

So, at the moment that chain appears OK.
John, thanks for that confirmation. There appear to be a couple of
things that need attention on the MSG-1 relay: sometimes the
segments are out of order which means that an initially incomplete
image is saved, and sometimes the feed into the MSG-1 processor
seems to get stuck, and we get repeated lines in the northern part
of the scan when the image at Eumetsat is perfect.

Eumetsat are working on these issues. From what I can gather, users
of the MSG Data Manager are well ahead of others in being able to
access these images.

Cheers,
David
Web: http://www.satsignal.net


Re: MSG-1 manoeuvre.

Alan Sewards <alan.sewards@...>
 

Anything that causes a change in the velocity vector of the spacecraft will
have the effect of changing the orbit - that is how it is moved. You have to
cause the opposite change at the end of the manoevre to stop it continuing
to move (Newton!).

A nice method of changing attitude and doing gentle stationkeeping is
through the use of momentum wheels. The only problem with these is that the
bearings tend to pack up after some years in space, and they need the
momentum to be dumped from time to time through the use of the thrusters. I
suspect Hubble has momentum wheels as this gives gentle movement and no
thruster pollution possibilities.

Regards - Alan

----- Original Message -----
From: "Dave Martin" <Dave.Martin@...>
To: <MSG-1@...>
Sent: Tuesday, December 09, 2003 4:31 PM
Subject: [MSG-1] Re: MSG-1 manoeuvre.



If it's a spin-stabilized bird, and not 3-axis stabilised, I wonder if the
simplest way to change orbital slot E - W might be to leave it spinning
totally undisturbed and just change the orbital period by slightly
raising/lowering the satellite's orbit ?

Dave M

----- Original Message -----
From: Luca Bertagnolio
To: MSG-1@...
Sent: Tuesday, December 09, 2003 9:13 AM
Subject: [MSG-1] Re: MSG-1 manoeuvre.


Alan,

you're right, but my understanding of MSG-1 tells me that it is not a
three axis stabilized craft, but rather a spin stabilized spacecraft.

If I am correct, I am wondering what kind of wobble effect, or other
gyroscopic effect, will be observed during the thrusters firing
activity.

It seems strange to me though that they would risk any contamination
of the imager with the exhaust particles coming from the
thrusters... HST (a much more sophisticated imager, I admit) has a
big lens "cap" door which is/was closed during the Shuttle
maintenance missions.

In any case, keep those Tq software running during the maneuvre, it
could be fun!

Bye, Luca


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Re: data but no imagery....

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

--- In MSG-1@..., Lawrence <lawrence@a...> wrote:
I trust that it is not just me that is seeing the data flow
without SEVIRI images? Yes, I read this morning's e-mail, but it is
puzzling to see the image files coming in now, but apparently empty.

Lawrence
Full images should be restored from the 16:45 repeat cycle onwards.

I do have a beta of the MSG Data Manager which will handle the mini-
scans on channels 1 to 11, but as this is not a production mode I am
not giving it any priority. If anyone wants the beta please let me
know.

Cheers
David


data but no imagery....

Lawrence <lawrence@...>
 

I trust that it is not just me that is seeing the data flow without
SEVIRI images? Yes, I read this morning's e-mail, but it is puzzling to
see the image files coming in now, but apparently empty.

Lawrence


Re: MSG-1 manoeuvre.

Alan Sewards <alan.sewards@...>
 

Guys,
I did NOT say that MSG1 was 3 axis stabilized, but that it had thrusters
which were capable of producing thrust in the three axes which are used for
attitude control and stationkeeping.

Try the following link:
http://www.eumetsat.de/en/index.html?area=left7.html&body=/en/dps/dissemination.html&a=710&b=1&c=700&d=700&e=0

The following is an excerpt from the link's target:


Satellite Propulsion

The MSG propulsion system inherits the unified bi-propellant system
already proven on communication satellites and some scientific missions. It
includes:

a.. 4 propellant tanks providing a large storage capacity (up to 965
kg of propellant)
b.. 2 helium pressurant tanks
c.. 2 liquid fuelled apogee motors each giving 400 N thrust for
apogee manoeuvres in transfer/drift orbits
d.. 6 reaction-control thrusters for fine orbital manoeuvres,
attitude acquisition and maintenance
Satellite Attitude and Orbit Control System AOCS

The MSG AOCS is designed on a minimum-complexity basis. It takes full
advantage of the Meteosat experience, and the fact that the spinner concept
provides gyroscopic stability. The onboard real time operations provide:

a.. attitude sensor processing and spin rate determination
b.. attitude and orbit manoeuvre synchronization
c.. active nutation damping.
The sensors comprise Sun slit sensors, Earth horizon crossing sensors,
and accelerometers.



I hope that clears it up!

Best regards - Alan

----- Original Message -----
From: <johnrigsec@...>
To: <MSG-1@...>
Sent: Tuesday, December 09, 2003 3:35 PM
Subject: Re: [MSG-1] Re: MSG-1 manoeuvre.


In a message dated 09-12-03 09:14:53 GMT Standard Time,
lucaberta@...
writes:

you're right, but my understanding of MSG-1 tells me that it is not a
three axis stabilized craft, but rather a spin stabilized spacecraft.
Hi Luca,

Yes, you are correct MSG-1 - indeed all the Meteosat craft are spin
stabilised.
Unlike the newer GOES which are three axis stabilised.

I am awaiting more information and confirmations from EUMETSAT on the
drift.

Regards,
John Tellick.






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Re: MSG-1 manoeuvre.

Dave Martin <Dave.Martin@...>
 

If it's a spin-stabilized bird, and not 3-axis stabilised, I wonder if the
simplest way to change orbital slot E - W might be to leave it spinning
totally undisturbed and just change the orbital period by slightly
raising/lowering the satellite's orbit ?

Dave M

----- Original Message -----
From: Luca Bertagnolio
To: MSG-1@...
Sent: Tuesday, December 09, 2003 9:13 AM
Subject: [MSG-1] Re: MSG-1 manoeuvre.


Alan,

you're right, but my understanding of MSG-1 tells me that it is not a
three axis stabilized craft, but rather a spin stabilized spacecraft.

If I am correct, I am wondering what kind of wobble effect, or other
gyroscopic effect, will be observed during the thrusters firing
activity.

It seems strange to me though that they would risk any contamination
of the imager with the exhaust particles coming from the
thrusters... HST (a much more sophisticated imager, I admit) has a
big lens "cap" door which is/was closed during the Shuttle
maintenance missions.

In any case, keep those Tq software running during the maneuvre, it
could be fun!

Bye, Luca


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Meteosat-5 problems?

johnrigsec@...
 

All,

I have just downloaded a direct WEFAX image from Meteosat-5 - 20:06.
The signal was very strong and steady and the WEFAX image perfect.

So, at the moment that chain appears OK.

The Arabian sea looks very warm and there appears to be a cyclone off
Sumatra.

Regards,
John Tellick.
RIG.


Re: MSG-1 manoeuvre.

johnrigsec@...
 

In a message dated 09-12-03 16:02:51 GMT Standard Time, Dave.Martin@...
writes:

If it's a spin-stabilized bird, and not 3-axis stabilised, I wonder if the
simplest way to change orbital slot E - W might be to leave it spinning
totally undisturbed and just change the orbital period by slightly
raising/lowering the satellite's orbit ?
Dave,

That is my understanding of how the drift occurs - boost it to a higher orbit
- it goes one
way, boost it to a lower orbit it drifts in the other direction - in relation
to the Earth.

I believe that is how the Shuttle and ISS 'catch up' with one another.

Regards,
John Tellick.


Missing segments

Peter Benney <tugboat@...>
 

As a result of "Lost Messages" I have had a few missing segments each day on the 0115 or 0145 cycles. The XP Home event log shows the following Security Success Audit at the relevant time. Any ideas ?...

Source: Security
Category: Logon/Logoff
Type: Success A
Event ID: 528
User: NT Authority/Network Service
Computer: Advent (Rx PC))

Description.
Successful Logon:
User Name: NETWORK SERVICE
Domain: NT AUTHORITY
Logon ID: (0x0 0x3E4)
Logon Type: 5
Logon Process: Advapi
Authentification Package: Negotiate
Workstation:Logon GUID: (00000000-0000-0000-000000000000)

Rx PC
AMD Athlon XP 2400+ (2.0GHz)
Motherboard: L7VTM VIA KT400
Memory: 1024MB DDR RAM - PC2100
Network Card: RealTek 8100L (onboard - RTL8139)
Windows XP Home Edition
Version 5.1.2600 Service Pack 1 Build 2600
BIOS Version/Date Phoenix Technologies, LTD 6.00 PG, 11/09/2002 (Latest)

Technisat Sky2PC USB box.
Software:
Technisat V4.2.8
Tellique V2.3.1

Regards,

Peter Benney


Re: MSG-1 manoeuvre.

johnrigsec@...
 

In a message dated 09-12-03 09:14:53 GMT Standard Time, lucaberta@...
writes:

you're right, but my understanding of MSG-1 tells me that it is not a
three axis stabilized craft, but rather a spin stabilized spacecraft.
Hi Luca,

Yes, you are correct MSG-1 - indeed all the Meteosat craft are spin
stabilised.
Unlike the newer GOES which are three axis stabilised.

I am awaiting more information and confirmations from EUMETSAT on the drift.

Regards,
John Tellick.


Re: MSG-1 manoeuvre.

johnrigsec@...
 

In a message dated 08-12-03 18:36:43 GMT Standard Time,
david-taylor@... writes:

John,

Many thanks for that information - you are the first source, as ever!

One question: the imager will be kept running, so does that mean
that the axis of the satellite remains parallel with the earth's
axis? Does that mean there are separate 3D stabilsed small
thrusters which can perform this operation, without having to use
the main on-axis engine?
David,

Very valid points and I don't know the answer - "but I know a man that does!"
I will get confirmation and further info.

I'm showing my ignorance here, I realise!<
Not at all David - you are held in the highest esteem!

Regards,
John.


Re: MSG-1 manoeuvre.

Luca Bertagnolio <lucaberta@...>
 

Alan,

you're right, but my understanding of MSG-1 tells me that it is not a
three axis stabilized craft, but rather a spin stabilized spacecraft.

If I am correct, I am wondering what kind of wobble effect, or other
gyroscopic effect, will be observed during the thrusters firing
activity.

It seems strange to me though that they would risk any contamination
of the imager with the exhaust particles coming from the
thrusters... HST (a much more sophisticated imager, I admit) has a
big lens "cap" door which is/was closed during the Shuttle
maintenance missions.

In any case, keep those Tq software running during the maneuvre, it
could be fun!

Bye, Luca

--- In MSG-1@..., "Alan Sewards" <alan.sewards@c...>
wrote:
David,
All modern satellites have three axis small thrusters for
attitude
control. These are used for stationkeeping also. The satellite will
have to
be reoriented when it arrives at its destination so it is just as
efficient
to do it little by little on the way there.


Re: MSG-1 manoeuvre.

Alan Sewards <alan.sewards@...>
 

David,
All modern satellites have three axis small thrusters for attitude
control. These are used for stationkeeping also. The satellite will have to
be reoriented when it arrives at its destination so it is just as efficient
to do it little by little on the way there.

Regards - Alan

----- Original Message -----
From: "David Taylor" <david-taylor@...>
To: <MSG-1@...>
Sent: Monday, December 08, 2003 7:16 PM
Subject: [MSG-1] Re: MSG-1 manoeuvre.


I had reported some time ago that MSG-1 would be drifted from its
present commissioning position of 10 deg. W to 3 deg. W (its
operational position) by late 2003 in preparation for the start of
operational '0 deg. longitude services' (replacing Meteosat-7's
operational service) in early January.
It would then be renamed Meteosat-8.

I have just been informed by EUMETSAT that the drift is now likely
to be the second week of January 2004.
I understand imaging will continue whilst the satellite is drifted.
John,

Many thanks for that information - you are the first source, as ever!

One question: the imager will be kept running, so does that mean
that the axis of the satellite remains parallel with the earth's
axis? Does that mean there are separate 3D stabilsed small
thrusters which can perform this operation, without having to use
the main on-axis engine?

I'm showing my ignorance here, I realise!

Cheers,
David



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Re: MSG-1 manoeuvre.

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

I had reported some time ago that MSG-1 would be drifted from its
present commissioning position of 10 deg. W to 3 deg. W (its
operational position) by late 2003 in preparation for the start of
operational '0 deg. longitude services' (replacing Meteosat-7's
operational service) in early January.
It would then be renamed Meteosat-8.

I have just been informed by EUMETSAT that the drift is now likely
to be the second week of January 2004.
I understand imaging will continue whilst the satellite is drifted.
John,

Many thanks for that information - you are the first source, as ever!

One question: the imager will be kept running, so does that mean
that the axis of the satellite remains parallel with the earth's
axis? Does that mean there are separate 3D stabilsed small
thrusters which can perform this operation, without having to use
the main on-axis engine?

I'm showing my ignorance here, I realise!

Cheers,
David


MSG-1 manoeuvre.

johnrigsec@...
 

All,

I had reported some time ago that MSG-1 would be drifted from its present
commissioning position of 10 deg. W to 3 deg. W (its operational position) by
late 2003 in preparation for the start of operational '0 deg. longitude services'
(replacing Meteosat-7's operational service) in early January.
It would then be renamed Meteosat-8.

I have just been informed by EUMETSAT that the drift is now likely to be the
second week of January 2004.
I understand imaging will continue whilst the satellite is drifted.

Registered EUMETCast users will be notified of developments.

Meteosat-7 will remain at 0 deg. longitude and continue WEFAX/HRI direct
dissemination till the end of 2005.

Regards,
John Tellick.


Meteosat-5 - visible channel errors

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

Once again, I am seeing errors in the Meteosat-5 visible channel at
0900 today. It seems as if the acquisition stopped only a short way
into the scan (starting at the south), leaving most of the image
northwards as a repetition of the last good line.

However, checking the Dundee image archive the data seems to be
fine. As far as I can tell, Dundee doesn't receive the Met-5 data
directly, so I am puzzled as to why there should be this
discrepancy. If Dundee can get good data, why can't the MSG feed?

It seems a pity, as the images are superb, when complete!

Cheers,
David


Re: newbie setting up for MSG

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

thanks for the replys saved me from spending money on hyper
threading P4 i will now purchase a normal one.
regards Peter
I recently upgraded, and actually bought a 2.8GHz hyper-threading
chip. I didn't realise it wasn't compatible (in HT mode) until I re-
read the Tellique instructions. However, I got it for the 800MHz
FSB, as I thought that would give a speed advantage over the 533MHz
FSB on the other processors. Yes, I did get the 400MHz DDR memory
to go with it. It is very fast!

(It runs my backup MSG-1 receiver with the Tellique software and the
MSG Data Manager, and is also used as a general purpose PC. When
CPU-intensive operations are run, missing segments result......).

Cheers,
David


Re: newbie setting up for MSG

peterszoo2003 <peter@...>
 

--- In MSG-1@..., "peterszoo2003" <peter@z...> wrote:
I am setting up for msg reception
I want to use a 1 computer setup I would like to know if a P4 3.06
GIG hyper threading processor is suitable will it work better than
the standard P4 northward 533 or do I realy nead a 2 computer
network
setup.
regards Peter
thanks for the replys saved me from spending money on hyper
threading P4 i will now purchase a normal one.
regards Peter


Re: newbie setting up for MSG

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

--- In MSG-1@..., "peterszoo2003" <peter@z...> wrote:
I am setting up for msg reception
Peter,

An obvious tip - search or scroll back through the messages to this
group as this has been discussed many times.

http://groups.yahoo.com/group/MSG-1/

I believe that John Tellick prepared a list of various systems and
how successful they were. Did you publish that, John?

Cheers,
David


Re: newbie setting up for MSG

Peter Benney <tugboat@...>
 

If you have the newer DVB card (V2.6B), be aware that the older
V4.2.2 drivers are the recommended ones, and not the newer V4.2.8
drivers supplied with the card.

Peter,

Further to David's good advice the FAQ refers to software V4.2.8 which I am running with the USB box but I thought I should draw your attention to this requirement.

Peter B