[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

20010306: a little more on nexrad radar & mcidas (cont.)



>From: alan anderson <address@hidden>
>Organization: St. Cloud State
>Keywords: 200102202133.f1KLXZL10511 McIDAS NEXRAD display

Alan,

>Below is the response I got from a John Kobar, listed as the Radar Data
>Contact person at NCDC. 
>
>It would appear that the raw binary data is the only format that NCDC has; 

Hmm...  I am suprised about this.  It could be that they are just
embarking on accumulating the Level III products.  The NCDC
representative on the Policy Committee has stated a couple of times
that they will be making both Level II and Level III data available.
Perhaps this is something for the future.

>I have the impression that image format is common;  if so, how, where are 
>the image files created?  

The Level III image products are created at the PUP.  The _great_ majority
of the Level III products are images.

>Thanks for all your help, even if this has led to a dead end for now.

I see from the file names that you currently have that your student is
looking for data from last year (April 16).  It is possible that
someone out there in the Unidata community has the Storm Total
Precipitation products (images) for that period and they will be
willing to give them to you.  Again, all you need to do is signup for
the needdata email list and post a request for the types of products
and the dates/times that you want.

To grease the wheels, as it were, I just added you:

address@hidden (Alan Anderson)

to the needdata list.  You can now post to it whenever you want.  Note
that the post must come from your email address as that is the one that
was added to the list.

>It was very useful in understanding how to set something like this up.

Sorry things were not easier.

If you/your student wants to get your/his feet wet, you can use McIDAS
to look at current NEXRAD Level III products for any/all NEXRAD sites.
The dataset to look at is RTNEXRAD:

1) point at adde.ucar.edu for the RTNEXRAD data:

DATALOC ADD RTNEXRAD ADDE.UCAR.EDU

2) get a listing of all sites that are generating NTP (Storm Total
Precipitation) products:

IMGLIST RTNEXRAD/NTP ID=LIST

3) display the latest such image from a site that is getting strong
predipitation:

IMGDISP RTNEXRAD/NTP ID=BOX EU=BREF REFRESH='EG;MAP H COU=ALL ST=MA;BAR'

(of course, the station you choose will need to be based on who is
getting precipitation.  I chose BOX (Boston, MA) since they have gotten
a good bit of precip. in the past couple of days.

If your student can use current radar data for his project (i.e., it is
not for a particular time), you should take advantage of the NEXRAD
products available on adde.ucar.edu.  We keep a rolling 15 day
"archive" of all products there.  The products for today (whatever day
is current) are always accessible through the RTNEXRAD dataset.  If you
want to see any image for any of the 15 days in the rolling archive,
you will need to use the NEXRALL dataset:

DATALOC ADD NEXRALL ADDE.UCAR.EDU
IMGLIST NEXRALL/NTP ID=BOX          <- lists the most recent image
IMGLIST NEXRALL/NTP.ALL ID=BOX      <- lists all of the NTP images for BOX

Since the server has to look though a LOT of images (something over
2500), the lists/displays/copies in the NEXRALL dataset will take
_considerably_ longer than the same operation on the RTNEXRAD dataset
(there are 1/15 th the number of images that have to be searched).  I
suggest that if you need to access the NEXRALL dataset that you help
the server out by defining your search a little more.  For instance,
here is the command that would list the images between 12 and 15 Z for
yesterday (today is now 2001066):

IMGLIST NEXRALL/NTP.ALL ID=BOX DAY=2001065 TIME=12 15

or with the DAY in a more friendly format:

IMGLIST NEXRALL/NTP.ALL ID=BOX DAY=2001/03/06 TIME=12 15

>>Hi Alan,
>
>>We do not have the Nexrad Level III data in an image file format.  The
>>two files provided were the raw binary Storm Total Precipitation data
>>like is send to NCDC from each radar site on a Write Once Read Many
>>(WORM) disk.  I do not believe we can fill this Level III order digitally
>>for Mr. Condor if he has to have a file format for the McIDAS software.
>>The only other way we provide Nexrad Level III data is as color hard copy
>>images.  The color hard copy images cost 15 dollars per image to obtain
>>from us.  Let me know if you have any additional questions.  Thanks.
>>John

Tom