20020103: Unidata FTP access to Unisys Radar data (cont.)

>From:  "Hongming Qi" <address@hidden>
>Organization:  NOAA
>Keywords:  200112202058.fBKKwvN27594 McIDAS ADDE Unisys

Hongming,

>   I tested these data in McIDAS7.802. Everything is same as what you
>said in the email. Only local Radar data could be displayed but national
>Radar data couldn't be displayed.

OK.

>From SSEC homepage, the national
>composite Radar data should be displayed by imgdisp command.

I believe that SSEC has a procedure that composites individual NEXRAD
Level III radar images into a national composite.  It is that composite
that can be displayed by IMGDISP, not the Unisys one.

>   Right now I am trying to convert these NIDS format data into McIDAS
>AREA format data.

You have everything you need right now.  Simply use the IMGCOPY command
from the NIDS dataset into one that is setup for imagery in AREA file
format.  Here is an example:

First make an output dataset of imagery in AREA format:

DSSERVE ADD NIDSAREA/N0R AREA 1 9999 TYPE=IMAGE "NEXRAD Level III Base 
Reflectivity in AREA format

Then do the copy:

IMGCOPY UNISYS/BREF2 NIDSAREA/NOR.1234 ID=* TIME=15:00 SIZE=ALL

You will end up with the BREF2 image in the AREA file AREA1234.  Depending
on if you have any McIDAS file REDIRECTions in place for AREA, this
image should end up in the first writable directory in your MCPATH.

>By looking through web, I found there was one report
>you wrote in your web site. The title is "McIDAS Support Status
>Activities for Winter 2000". You mentioned "rewrite of NEXRAD Level III
>to McIDAS AREA converter (in progress)" in this report. Do you still
>have any information about such conversion?

I have a package that I maintain called ldm-mcidas which has a routine
that will convert WSI NIDS products into AREA format.  This probably
could be used (perhaps with slight tweaking) with the Unisys images,
but you don't really need it given that you can create the output
AREA files using McIDAS itself.

>Where can I find the
>detailed information about Radar data in NIDS format like how to store
>header and how many bytes in header section?

The format is documented in several government publications.  Do you
really need this information given that you can do the conversion you
are after with no additional work?

>Thanks,

I've got to run right now.  Please let me know if you want me to dig up
a reference for the format of NIDS (aka NEXRAD Level III) products.  Again,
I don't think you need this, but, then again, I don't know exactly what
you are trying to accomplish.

>Hongming
>
>Tom Yoksas wrote:
>> 
>> >From:  "Hongming Qi" <address@hidden>
>> 
>> Hongming,
>> 
>> >  Happy holiday!
>> 
>> Same to you (belatedly)!
>> 
>> >I have saved some NIDS radar data on machine gp16.wwb.noaa.gov. The
>> >directory is /pub/radar. You can ftp these files by anonymous account.
>> >There are two kind of NIDS data in this directory.
>> >1)BREF2_1.00_20011226_15* is local radar data (only Maryland).
>> >2)BREF_2.00_20011226_15* is the national radar data.
>> >
>> >  Let me know if any problem.
>> 
>> I can not display the Unisys composite base reflectivity images.  The
>> format of these files is enough like others supported in Unidata McIDAS
>> (i.e., WSI NOWrad (tm) composites) that creating a new server or
>> extending an existing server to support them would not be too much of a
>> chore.
>> 
>> I can display the NEXRAD Level III products in McIDAS-X (any 7.8x
>> version), but I can not select images by station ID.  What I mean by
>> this is that for the files you provided, the station ID is not in a
>> format that is currently understood by the versions of McIDAS that can
>> display NEXRAD Level III products (typically McIDAS-X 7.8x).  The code
>> needs to be updated to unpack the numeric station number which then
>> needs to be used in a lookup to get the station ID.  This is a mod that
>> I have know was needed for some time, but have simply not gotten around
>> to making.
>> 
>> If you running a current release of McIDAS (i.e., 7.8x), you can display
>> the Level III products.  Here is one example of setting up an ADDE
>> dataset to do this:
>> 
>> 1) put all of the Level III BREF products in a directory structure like:
>> 
>>    /home/mcidas/unisys/nids/BREF2
>> 
>> 2) create an ADDE dataset to access these images:
>> 
>> DSSERVE ADD UNISYS/BREF2 NEXR DIRFILE=/home/mcidas/unisys/nids/BREF2/BREF2* 
> TYPE=IMAGE "UNISYS NEXRAD Level III Base Reflectivity 2 images
>> 
>> 3) list the files using McIDAS:
>> 
>> IMGLIST UNISYS/BREF2.ALL ID=*
>> Image file directory listing for:UNISYS/BREF2
>>  Pos Satellite/         Date       Time      Center   Band(s)
>>      sensor                                 Lat  Lon
>>  --- -------------  ------------  --------  ---- ---- ------------
>>    1  RADAR         26 DEC 01360  15:00:00     ððð    1
>>    2  RADAR         26 DEC 01360  15:10:00     ðð?    1
>> IMGLIST: done
>> 
>>    Notice how the field under 'Lat Lon' is garbage.  This is because
>>    the ADDE server does not know how to extract and use the numeric
>>    station ID that is currently in the file.  The modifications to
>>    support this are what I need to add to the server and provide to
>>    you.  I will see if I can do the work before the AMS conference.
>> 
>> 4) Display the image in position 2:
>> 
>> IMGDISP UNISYS/BREF2.2 ID=* EU=BREF REFRESH='EG;MAP X 5 COU=ALL;MAP X 1'
>> Beginning Image Data transfer, bytes= 519864
>> IMGDISP: loaded frame  1
>> EG;MAP X 5 COU=ALL;MAP X 1
>> Erased graphic frame(s) 1-1
>> IMGDISP: done
>> EU: Restoring BREF.ET      to frame(s)=   1
>> EU: Done
>> MAP: Completed frame 1
>> MAP: Completed frame 1
>> 
>> 5) Display the image for 15:00:
>> 
>> IMGDISP UNISYS/BREF2 TIME=15:00 ID=* EU=BREF REFRESH='EG;MAP X 5 COU=ALL;MAP
>  X 1'
>> Beginning Image Data transfer, bytes= 519864
>> IMGDISP: loaded frame  1
>> EG;MAP X 5 COU=ALL;MAP X 1
>> IMGDISP: done
>> EU: Restoring BREF.ET      to frame(s)=   1
>> EU: Done
>> Erased graphic frame(s) 1-1
>> MAP: Completed frame 1
>> MAP: Completed frame 1
>> 
>> >Thank you for your help
>> 
>> You are welcome.  Do you want me to let you know when I have altered
>> the McIDAS ADDE NEXRAD server code to support use of the numeric station
>> ID?

Tom
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