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Re: 20020910: Creating 24-hour Radar Est. Precip Image




Daryl,

A few other tid bits when I get the 5.6.h release officially released
in the next day or so (staff meetings, web site redesign, etc. withstanding):

1) I added the ability to specify the missing data value in gdradr-
   that is, what value should be assigned to ND (defaults to RMISSD).
   For N1P and NTP, the missing value can be assumed to be 0, but
   for N0R for example, it would be impossible to place a lower dBZ
   value.

2) I added a grid diagnostic function to set the MISSING data value to
   some other value (I think I sent this change to you at the time)
   which will be the MISS(S1,S2) function as shown at:

http://www.unidata.ucar.edu/packages/gempak/tutorial/manual/chap3/chap3.shtml?gparm

   This should help  in some computations when you want to sum "0" or
   some other value- instead of setting the grid point to missing.

Steve Chiswell
Unidata User Support

On Tue, 10 Sep 2002, Daryl Herzmann wrote:

>
> Augh.  I withdraw my previous post.  <unsend> <unsend>
>
> I need to use gdstat instead of other programs.
>
> Thanks
>   Daryl
>
> On Tue, 10 Sep 2002, Steve Chiswell wrote:
>
> >Patrick,
> >
> >See the GDSTAT program for a time series of your N1P grids.
> >GDSTAT will compute AVG, STD, and CNT for the time series-
> >adding the derived parameters to the GDOUTF. You can back out
> >a SUM using GDDIAG and multiplying the AVG and CNT fields.
> >
> >Steve Chiswell
> >Unidata User Support
> >
> >On Tue, 10 Sep 2002, Patrick O'Reilly wrote:
> >
> >> Hello gembud'ers,
> >>
> >> I have been assigned the task of getting a 24-hour radar estimated precip 
> >> image created using Gempak.  I was planning to (hourly) take a one-hour 
> >> precip image, and use GDRADR to create a grid of the image.  Then, take 
> >> these 24 grids and somehow add them to get a 24-hour total precip grid.  
> >> Or maybe add them as I went.  This sounded great in theory, but I can't 
> >> figure out how to make this work.  I tinkered with GDEDIT, adding grids, 
> >> but it doesn't add different grids, just adds another seperate grid.  I 
> >> guess basically, I need to know how to add these radar grids to make one 
> >> total for the 24-hour period.  Any ideas or suggestions about a method 
> >> would be welcome.
> >>
> >> Patrick
> >> _______________________________________
> >> Patrick O'Reilly
> >> Meteorological Decision Support Scientist
> >> The STORM Project - University of Northern Iowa
> >> address@hidden  ~  ph: 319-273-3789
> >>
> >
> >
>
> --
> /**
>  * Daryl Herzmann (address@hidden)
>  * Program Assistant -- Iowa Environmental Mesonet
>  * http://mesonet.agron.iastate.edu
>  */
>
>