Re: IDL code to read MSU and HIRS in Level1b [message #40556] |
Thu, 19 August 2004 02:27  |
marcuirl
Messages: 14 Registered: December 2003
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Junior Member |
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Yamout <hossein@uni-bonn.de> writes:
> So I am looking around to find a kind human being help me
> discovering the real differences or get an IDL code to read or at
> leat convert them in a for me readable format (BIL, BIP, BSQ, or
> just ACII). I have attached a sample data in my previous posting,
> but if you have cannot access it any more, just let me know.
A simple google search MSU and HIRS IDL gave this. It might help
http://cimss.ssec.wisc.edu/~gumley/imagemap.html
marcu
--
Unless otherwise noted, the statements herein reflect my
personal opinions and not those of any organisation with
which I may be affiliated.
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Re: IDL code to read MSU and HIRS in Level1b [message #40557 is a reply to message #40556] |
Thu, 19 August 2004 01:26   |
Yamout
Messages: 8 Registered: August 2004
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Junior Member |
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Dear Mark,
thank you for your reply. As I said, I have ENVI with full version of
IDL unfortunately in PC (windows) platform. As you have written there
are some differences between the before and after 1995 formats. I have
asked SAA people and they can only send me such "helps" which I knew
already.
------------------------------------------
In response to your SAA Help Desk inquiry
E-Mail : Dear Hossein Yamout,
The only difference between the data from before and after January
1, 1995 is the record length. For data from prior to 1995, there were
additional spare bytes at the end of each data record, effectively
increasing the overall record length. In particular, for the line item
you referenced, L5409101, which was for MSU data, you will want to look
at section 4.3 of the POD Guide
http://www2.ncdc.noaa.gov/docs/podug/html/c4/sec4-3.htm
If you look at table 4.3.2.1-1. titled Format of MSU data, you will
see that pre-1995 data had spare bytes in byte locations 401 to 440
while the data starting in 1995 had spare bytes in byte locations 401 to
437. Otherwise, the formats are identical. If you are interested in the
other TOVS data types, they too had a record length change starting in
1995. The appropriate section of the POD Guide spells out the record
length change for these data types as well. For SSU data, see
http://www2.ncdc.noaa.gov/docs/podug/html/c4/sec4-2.htm
and for HIRS data see
http://www2.ncdc.noaa.gov/docs/podug/html/c4/sec4-1.htm
I hope this clarifies this matter for you.
Sincerely,
CLASS Help Desk
---------------------------------------------
So I am looking around to find a kind human being help me discovering
the real differences or get an IDL code to read or at leat convert them
in a for me readable format (BIL, BIP, BSQ, or just ACII). I have
attached a sample data in my previous posting, but if you have cannot
access it any more, just let me know.
Regards
Hossein
~~~~~~~~
Mark Hadfield wrote:
> Do you have any software (in any language) that *does* read these data
> files? Or the post-1995 files?
>
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Re: IDL code to read MSU and HIRS in Level1b [message #40570 is a reply to message #40569] |
Wed, 18 August 2004 09:56   |
Yamout
Messages: 8 Registered: August 2004
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Junior Member |
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David Fanning wrote:
> Yamout writes:
>
>
>> Is there any kind human being who can help an illiterate student to read
>> a few MSU and HIRS data of NOAA 1991. I have got them from
>> www.saa.noaa.gov and they have some differences with LAC and GAC.
>> I have ENVI with full version of IDL installed in PC with Windows NT.
>
>
> That's a pretty powerful weapon you have there. Are you
> *sure* nobody told you how to use it? :-(
>
> Cheers,
>
> David
Dear David,
thank you very much fro your reply. No, unfortunately I am sure that
nobody have told me how to use it. The format description is not the
most convenient one. I have got the following message from SAA after
many mail exchanges:
--------------------------
In response to your SAA Help Desk inquiry
E-Mail : Dear Hossein Yamout,
The only difference between the data from before and after January
1, 1995 is the record length. For data from prior to 1995, there were
additional spare bytes at the end of each data record, effectively
increasing the overall record length. In particular, for the line item
you referenced, L5409101, which was for MSU data, you will want to look
at section 4.3 of the POD Guide
http://www2.ncdc.noaa.gov/docs/podug/html/c4/sec4-3.htm
If you look at table 4.3.2.1-1. titled Format of MSU data, you will
see that pre-1995 data had spare bytes in byte locations 401 to 440
while the data starting in 1995 had spare bytes in byte locations 401 to
437. Otherwise, the formats are identical. If you are interested in the
other TOVS data types, they too had a record length change starting in
1995. The appropriate section of the POD Guide spells out the record
length change for these data types as well. For SSU data, see
http://www2.ncdc.noaa.gov/docs/podug/html/c4/sec4-2.htm
and for HIRS data see
http://www2.ncdc.noaa.gov/docs/podug/html/c4/sec4-1.htm
I hope this clarifies this matter for you.
Sincerely,
CLASS Help Desk
------------------------------------
Do like to probe the data, so that I send you a sample? It is 127282 byte.
Regards
Hossein
~~~~~~~
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Re: IDL code to read MSU and HIRS in Level1b [message #40643 is a reply to message #40557] |
Thu, 19 August 2004 14:34  |
Mark Hadfield
Messages: 783 Registered: May 1995
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Senior Member |
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Yamout wrote:
> Dear Mark,
>
> thank you for your reply. As I said, I have ENVI with full version of
> IDL unfortunately in PC (windows) platform. As you have written there
> are some differences between the before and after 1995 formats. I have
> asked SAA people and they can only send me such "helps" which I knew
> already.
So are you saying that you *can* read the post-1995 format? If so, how?
Is there any possibility of your modifying the reader for the post-1995
file so that it will cope with the difference in record length?
Please be patient if the answers to these questions seem obvious to you,
but I don't know much about ENVI. Please realise when you post questions
to a news group that you need to give the readers enough information for
them to help you.
---
Mark Hadfield "Ka puwaha te tai nei, Hoea tatou"
m.hadfield@niwa.co.nz
National Institute for Water and Atmospheric Research (NIWA)
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