[Met_help] [rt.rap.ucar.edu #52847] History for validate WRF with satellite data

Fri Jan 27 09:53:51 MST 2012

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  Initial Request
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Dear MET help,

I am interested using satellite dataset to validate WRF model output, say TRMM precipitation radar with WRF radar reflectivity field.  I am wondering what is the best way of doing this, especially for preparing the data to do the statistics?  Not very familiar with copygb, but wondering if it is doable with it.

Thanks,
Di

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  Complete Ticket History
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Subject: Re: [rt.rap.ucar.edu #52847] validate WRF with satellite data
From: John Halley Gotway
Time: Thu Jan 19 15:26:41 2012

Di,

Please take a look at the sample scripts posted on the MET website:
    http://www.dtcenter.org/met/users/downloads/analysis_scripts.php

At the bottom is an Rscript (trmm2nc.R) for pre-processing TRMM data
into a gridded NetCDF data file that MET can read.  However, there's
no easy way of regridding that TRMM data onto your model
domain.  Instead, you'll likely need to run copygb to regrid your
model output onto the same domain as the TRMM data.

After post-processing your WRF model output using either the WRF
PostProcessor (WPP) or the Unified PostProcess (UPP), you'll have GRIB
version 1 files.  And copygb can be used to regrid them.
Examples of how to do this with copygb can be found at this link in
the MET online tutorial:
    http://www.dtcenter.org/met/users/support/online_tutorial/METv3.0/copygb/index.php

Just click the forward arrow button in the bottom-right corner of that
page to step through the examples of using copygb for different
projection types.

Hope that helps.

John Halley Gotway
met_help at ucar.edu

On 01/19/2012 03:14 PM, Wu, Di[SCIENCE SYSTEMS APPLICATIONS] via RT
wrote:
>
> Thu Jan 19 15:14:38 2012: Request 52847 was acted upon.
> Transaction: Ticket created by di.wu at nasa.gov
>         Queue: met_help
>       Subject: validate WRF with satellite data
>         Owner: Nobody
>    Requestors: di.wu at nasa.gov
>        Status: new
>   Ticket<URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=52847>
>
>
> Dear MET help,
>
> I am interested using satellite dataset to validate WRF model
output, say TRMM precipitation radar with WRF radar reflectivity
field.  I am wondering what is the best way of doing this, especially
for preparing the data to do the statistics?  Not very familiar with
copygb, but wondering if it is doable with it.
>
> Thanks,
> Di

------------------------------------------------
Subject: Re: [rt.rap.ucar.edu #52847] validate WRF with satellite data
From: Wu, Di[SCIENCE SYSTEMS APPLICATIONS]
Time: Fri Jan 20 13:05:36 2012

Hi, John

Thanks for your prompt answer.
I saw there are output available for AMSR-E brightness temperature in
the UPP documentation and I am wondering if copygb also supports AMSR-
E observation (in HDF format) or other satellite observation?

Di

On Jan 19, 2012, at 5:26 PM, John Halley Gotway via RT wrote:

> Di,
>
> Please take a look at the sample scripts posted on the MET website:
>    http://www.dtcenter.org/met/users/downloads/analysis_scripts.php
>
> At the bottom is an Rscript (trmm2nc.R) for pre-processing TRMM data
into a gridded NetCDF data file that MET can read.  However, there's
no easy way of regridding that TRMM data onto your model
> domain.  Instead, you'll likely need to run copygb to regrid your
model output onto the same domain as the TRMM data.
>
> After post-processing your WRF model output using either the WRF
PostProcessor (WPP) or the Unified PostProcess (UPP), you'll have GRIB
version 1 files.  And copygb can be used to regrid them.
> Examples of how to do this with copygb can be found at this link in
the MET online tutorial:
>
http://www.dtcenter.org/met/users/support/online_tutorial/METv3.0/copygb/index.php
>
> Just click the forward arrow button in the bottom-right corner of
that page to step through the examples of using copygb for different
projection types.
>
> Hope that helps.
>
> John Halley Gotway
> met_help at ucar.edu
>
> On 01/19/2012 03:14 PM, Wu, Di[SCIENCE SYSTEMS APPLICATIONS] via RT
wrote:
>>
>> Thu Jan 19 15:14:38 2012: Request 52847 was acted upon.
>> Transaction: Ticket created by di.wu at nasa.gov
>>        Queue: met_help
>>      Subject: validate WRF with satellite data
>>        Owner: Nobody
>>   Requestors: di.wu at nasa.gov
>>       Status: new
>>  Ticket<URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=52847>
>>
>>
>> Dear MET help,
>>
>> I am interested using satellite dataset to validate WRF model
output, say TRMM precipitation radar with WRF radar reflectivity
field.  I am wondering what is the best way of doing this, especially
for preparing the data to do the statistics?  Not very familiar with
copygb, but wondering if it is doable with it.
>>
>> Thanks,
>> Di
>

------------------------------------------------
Subject: Re: [rt.rap.ucar.edu #52847] validate WRF with satellite data
From: John Halley Gotway
Time: Fri Jan 20 13:12:33 2012

Di,

I'm a bit confused on your question.  So let me explain the basic
functionality of copygb - it is a utility that can be used to
interpolate GRIB version 1 files from one grid to another.  If you
have
any data that is not in GRIB1 format, copygb will not be of any use to
you.

Prior to using MET to compare datasets on two different grids, you'll
first need to get them onto the same grid in a format that MET can
read.  For gridded data, that's currently GRIB1, the NetCDF
output from the WRF-ARW pinterp tool, and the internal NetCDF format
that MET uses.  That trmm2nc.R script basically reformats the ASCII
trmm data into that internal MET NetCDF format.

Adding direct support for additional gridded datasets in MET is a
longer term goal - including support for GRIB2 and the NetCDF CF-
convention.

As is often the case, preparing your data is one of the most difficult
parts.

Hope that helps clarify.

John

On 01/20/2012 01:05 PM, Wu, Di[SCIENCE SYSTEMS APPLICATIONS] via RT
wrote:
>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=52847>
>
> Hi, John
>
> Thanks for your prompt answer.
> I saw there are output available for AMSR-E brightness temperature
in the UPP documentation and I am wondering if copygb also supports
AMSR-E observation (in HDF format) or other satellite observation?
>
> Di
>
> On Jan 19, 2012, at 5:26 PM, John Halley Gotway via RT wrote:
>
>> Di,
>>
>> Please take a look at the sample scripts posted on the MET website:
>>
http://www.dtcenter.org/met/users/downloads/analysis_scripts.php
>>
>> At the bottom is an Rscript (trmm2nc.R) for pre-processing TRMM
data into a gridded NetCDF data file that MET can read.  However,
there's no easy way of regridding that TRMM data onto your model
>> domain.  Instead, you'll likely need to run copygb to regrid your
model output onto the same domain as the TRMM data.
>>
>> After post-processing your WRF model output using either the WRF
PostProcessor (WPP) or the Unified PostProcess (UPP), you'll have GRIB
version 1 files.  And copygb can be used to regrid them.
>> Examples of how to do this with copygb can be found at this link in
the MET online tutorial:
>>
http://www.dtcenter.org/met/users/support/online_tutorial/METv3.0/copygb/index.php
>>
>> Just click the forward arrow button in the bottom-right corner of
that page to step through the examples of using copygb for different
projection types.
>>
>> Hope that helps.
>>
>> John Halley Gotway
>> met_help at ucar.edu
>>
>> On 01/19/2012 03:14 PM, Wu, Di[SCIENCE SYSTEMS APPLICATIONS] via RT
wrote:
>>>
>>> Thu Jan 19 15:14:38 2012: Request 52847 was acted upon.
>>> Transaction: Ticket created by di.wu at nasa.gov
>>>         Queue: met_help
>>>       Subject: validate WRF with satellite data
>>>         Owner: Nobody
>>>    Requestors: di.wu at nasa.gov
>>>        Status: new
>>>   Ticket<URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=52847>
>>>
>>>
>>> Dear MET help,
>>>
>>> I am interested using satellite dataset to validate WRF model
output, say TRMM precipitation radar with WRF radar reflectivity
field.  I am wondering what is the best way of doing this, especially
for preparing the data to do the statistics?  Not very familiar with
copygb, but wondering if it is doable with it.
>>>
>>> Thanks,
>>> Di
>>
>

------------------------------------------------
Subject: Re: [rt.rap.ucar.edu #52847] validate WRF with satellite data
From: Wu, Di[SCIENCE SYSTEMS APPLICATIONS]
Time: Fri Jan 20 13:22:20 2012

John,

Sorry for the confusion.  By copygb, I actually mean any trmm2nc.R
like *R script for other dataset.
If I understand correctly, you can prepare any observational dataset
to be readily used by MET as long as converted into NetCDF format,
following certain convention?

Thanks,
Di

On Jan 20, 2012, at 3:12 PM, John Halley Gotway via RT wrote:

> Di,
>
> I'm a bit confused on your question.  So let me explain the basic
functionality of copygb - it is a utility that can be used to
interpolate GRIB version 1 files from one grid to another.  If you
have
> any data that is not in GRIB1 format, copygb will not be of any use
to you.
>
> Prior to using MET to compare datasets on two different grids,
you'll first need to get them onto the same grid in a format that MET
can read.  For gridded data, that's currently GRIB1, the NetCDF
> output from the WRF-ARW pinterp tool, and the internal NetCDF format
that MET uses.  That trmm2nc.R script basically reformats the ASCII
trmm data into that internal MET NetCDF format.
>
> Adding direct support for additional gridded datasets in MET is a
longer term goal - including support for GRIB2 and the NetCDF CF-
convention.
>
> As is often the case, preparing your data is one of the most
difficult parts.
>
> Hope that helps clarify.
>
> John
>
> On 01/20/2012 01:05 PM, Wu, Di[SCIENCE SYSTEMS APPLICATIONS] via RT
wrote:
>>
>> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=52847>
>>
>> Hi, John
>>
>> Thanks for your prompt answer.
>> I saw there are output available for AMSR-E brightness temperature
in the UPP documentation and I am wondering if copygb also supports
AMSR-E observation (in HDF format) or other satellite observation?
>>
>> Di
>>
>> On Jan 19, 2012, at 5:26 PM, John Halley Gotway via RT wrote:
>>
>>> Di,
>>>
>>> Please take a look at the sample scripts posted on the MET
website:
>>>
http://www.dtcenter.org/met/users/downloads/analysis_scripts.php
>>>
>>> At the bottom is an Rscript (trmm2nc.R) for pre-processing TRMM
data into a gridded NetCDF data file that MET can read.  However,
there's no easy way of regridding that TRMM data onto your model
>>> domain.  Instead, you'll likely need to run copygb to regrid your
model output onto the same domain as the TRMM data.
>>>
>>> After post-processing your WRF model output using either the WRF
PostProcessor (WPP) or the Unified PostProcess (UPP), you'll have GRIB
version 1 files.  And copygb can be used to regrid them.
>>> Examples of how to do this with copygb can be found at this link
in the MET online tutorial:
>>>
http://www.dtcenter.org/met/users/support/online_tutorial/METv3.0/copygb/index.php
>>>
>>> Just click the forward arrow button in the bottom-right corner of
that page to step through the examples of using copygb for different
projection types.
>>>
>>> Hope that helps.
>>>
>>> John Halley Gotway
>>> met_help at ucar.edu
>>>
>>> On 01/19/2012 03:14 PM, Wu, Di[SCIENCE SYSTEMS APPLICATIONS] via
RT wrote:
>>>>
>>>> Thu Jan 19 15:14:38 2012: Request 52847 was acted upon.
>>>> Transaction: Ticket created by di.wu at nasa.gov
>>>>        Queue: met_help
>>>>      Subject: validate WRF with satellite data
>>>>        Owner: Nobody
>>>>   Requestors: di.wu at nasa.gov
>>>>       Status: new
>>>>  Ticket<URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=52847>
>>>>
>>>>
>>>> Dear MET help,
>>>>
>>>> I am interested using satellite dataset to validate WRF model
output, say TRMM precipitation radar with WRF radar reflectivity
field.  I am wondering what is the best way of doing this, especially
for preparing the data to do the statistics?  Not very familiar with
copygb, but wondering if it is doable with it.
>>>>
>>>> Thanks,
>>>> Di
>>>
>>
>

------------------------------------------------
Subject: Re: [rt.rap.ucar.edu #52847] validate WRF with satellite data
From: John Halley Gotway
Time: Fri Jan 20 14:33:34 2012

Di,

Yes, that's correct.  You can reformat data into a NetCDF format that
MET can read.  Unfortunately, I can't point you to a document that
describes in great detail what that format should be.  The best
way to get started is to just emulate the NetCDF output of the
trmm2nc.R script or the NetCDF output the MET pcp_combine tool (when
you run the MET test scripts, that output will be generated).

If you go down that path, and questions arise, we're happy to answer
them.  But we're busy right now working on the next release, so I
don't have time to write up anything formal at this point.

However, data formats aside, if you want to do a grid-to-grid
comparison, you'll need to put your forecast and observation datasets
onto a common grid.

Thanks,
John

On 01/20/2012 01:22 PM, Wu, Di[SCIENCE SYSTEMS APPLICATIONS] via RT
wrote:
>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=52847>
>
> John,
>
> Sorry for the confusion.  By copygb, I actually mean any trmm2nc.R
like *R script for other dataset.
> If I understand correctly, you can prepare any observational dataset
to be readily used by MET as long as converted into NetCDF format,
following certain convention?
>
> Thanks,
> Di
>
> On Jan 20, 2012, at 3:12 PM, John Halley Gotway via RT wrote:
>
>> Di,
>>
>> I'm a bit confused on your question.  So let me explain the basic
functionality of copygb - it is a utility that can be used to
interpolate GRIB version 1 files from one grid to another.  If you
have
>> any data that is not in GRIB1 format, copygb will not be of any use
to you.
>>
>> Prior to using MET to compare datasets on two different grids,
you'll first need to get them onto the same grid in a format that MET
can read.  For gridded data, that's currently GRIB1, the NetCDF
>> output from the WRF-ARW pinterp tool, and the internal NetCDF
format that MET uses.  That trmm2nc.R script basically reformats the
ASCII trmm data into that internal MET NetCDF format.
>>
>> Adding direct support for additional gridded datasets in MET is a
longer term goal - including support for GRIB2 and the NetCDF CF-
convention.
>>
>> As is often the case, preparing your data is one of the most
difficult parts.
>>
>> Hope that helps clarify.
>>
>> John
>>
>> On 01/20/2012 01:05 PM, Wu, Di[SCIENCE SYSTEMS APPLICATIONS] via RT
wrote:
>>>
>>> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=52847>
>>>
>>> Hi, John
>>>
>>> Thanks for your prompt answer.
>>> I saw there are output available for AMSR-E brightness temperature
in the UPP documentation and I am wondering if copygb also supports
AMSR-E observation (in HDF format) or other satellite observation?
>>>
>>> Di
>>>
>>> On Jan 19, 2012, at 5:26 PM, John Halley Gotway via RT wrote:
>>>
>>>> Di,
>>>>
>>>> Please take a look at the sample scripts posted on the MET
website:
>>>>
http://www.dtcenter.org/met/users/downloads/analysis_scripts.php
>>>>
>>>> At the bottom is an Rscript (trmm2nc.R) for pre-processing TRMM
data into a gridded NetCDF data file that MET can read.  However,
there's no easy way of regridding that TRMM data onto your model
>>>> domain.  Instead, you'll likely need to run copygb to regrid your
model output onto the same domain as the TRMM data.
>>>>
>>>> After post-processing your WRF model output using either the WRF
PostProcessor (WPP) or the Unified PostProcess (UPP), you'll have GRIB
version 1 files.  And copygb can be used to regrid them.
>>>> Examples of how to do this with copygb can be found at this link
in the MET online tutorial:
>>>>
http://www.dtcenter.org/met/users/support/online_tutorial/METv3.0/copygb/index.php
>>>>
>>>> Just click the forward arrow button in the bottom-right corner of
that page to step through the examples of using copygb for different
projection types.
>>>>
>>>> Hope that helps.
>>>>
>>>> John Halley Gotway
>>>> met_help at ucar.edu
>>>>
>>>> On 01/19/2012 03:14 PM, Wu, Di[SCIENCE SYSTEMS APPLICATIONS] via
RT wrote:
>>>>>
>>>>> Thu Jan 19 15:14:38 2012: Request 52847 was acted upon.
>>>>> Transaction: Ticket created by di.wu at nasa.gov
>>>>>         Queue: met_help
>>>>>       Subject: validate WRF with satellite data
>>>>>         Owner: Nobody
>>>>>    Requestors: di.wu at nasa.gov
>>>>>        Status: new
>>>>>   Ticket<URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=52847>
>>>>>
>>>>>
>>>>> Dear MET help,
>>>>>
>>>>> I am interested using satellite dataset to validate WRF model
output, say TRMM precipitation radar with WRF radar reflectivity
field.  I am wondering what is the best way of doing this, especially
for preparing the data to do the statistics?  Not very familiar with
copygb, but wondering if it is doable with it.
>>>>>
>>>>> Thanks,
>>>>> Di
>>>>
>>>
>>
>

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