HRV Channel 12


Ian S Deans <ian@...>
 

Did anyone else see a strange anomaly on HRIT channel 12 at 14.30. over
Africa or was this just part of my on going problem with segment loss.
Strangely enough segment loss on LRIT has been extremely rare, but today the
12.00 Met 5 images were terrible with segments 5-10 missing on the visible
and segment 5 missing on both IR and WV, presumably all part of my problem.

Regards

Ian


David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

Strangely enough segment loss on LRIT has been extremely rare, but
today the 12.00 Met 5 images were terrible with segments 5-10
missing on the visible and segment 5 missing on both IR and WV,
presumably all part of my problem.
No, same here. I see the Met-5 12:00 segments coming in since
15:00...... Can't comment on HRV right now.

David


Douglas Deans <douglas@...>
 

----- Original Message -----
From: "Ian S Deans" <ian@isdeans.freeserve.co.uk>
To: <MSG-1@yahoogroups.com>
Sent: Monday, December 22, 2003 3:33 PM
Subject: [MSG-1] HRV Channel 12


Did anyone else see a strange anomaly on HRIT channel 12 at 14.30. over
Africa or was this just part of my on going problem with segment loss.
Strangely enough segment loss on LRIT has been extremely rare, but today
the
12.00 Met 5 images were terrible with segments 5-10 missing on the visible
and segment 5 missing on both IR and WV, presumably all part of my
problem.

Regards

Ian
The strange anomaly is in fact present on all the 14.30 images and can be
seen between approx. 16� - 20� S latitude. A small blip in the SEVIRI or
probably software.

By now you will have seen that the majority of the Met 5 segments for 12.00
came in after 15.00 !
Not surprised you assumed it to be associated with your current segment
issue. The FSD data is not coming in timeously at the moment. One wonders
if eventually channel 3 may need a bandwidth tweak.

Regards
Douglas.


David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

--- In MSG-1@yahoogroups.com, "Ian S Deans" <ian@i...> wrote:
Did anyone else see a strange anomaly on HRIT channel 12 at 14.30.
over Africa or was this just part of my on going problem with
segment loss.

What do you mean, Ian. What pixel location or lat and
lon? "Africa" covers a fair number of pixels!

The only thing I can see is that the switch from lower window to
upper window seems a little less "clean" than usual. However, the
1415 and 1445 images look similar.

Segment loss would cause a break of 464 lines in the image. If you
have the Clear images box checked, that 464 lines should show as a
black area, with precisely horizontal edges, and exactly 464 lines
high.

I mention this in detail because sometimes there are gaps in the
Foreign Satellite Data which do _not_ have exactly horizontal edges,
and these gaps are caused by gaps in the unrectified source data.
The gap in the source has edges in the plane of the scan, but the
scan plane may not be parallel to the equator because of the
inclination of the orbit. When the rectified image is viewed, the
scan gaps are no longer horizontal. I expect you already knew this,
but others may not.

Cheers,
David


David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

The strange anomaly is in fact present on all the 14.30 images and
can be seen between approx. 16° - 20° S latitude. A small blip in
the SEVIRI or probably software.

Yes, same here, Scanner or scan position sensor. Is this the
region that was hammered by the mini-scans the other day?


The FSD data is not coming in timeously at the moment.
"timeously" - Scottish? Meaning on-time (I am told).

One wonders if eventually channel 3 may need a bandwidth tweak.
I think you are correct - perticularly when all the other goodies
are added like 30-minute Met-5 and Met-7 data next year. Changing
the bandwidth would not have been possible if direct dissemination
from MSG-1 were in use, so again many thanks to the SSPA designer!

Cheers,
David