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Re: 20010216: netCDF satellite imagery for NAWIPS



Kevin,

I make both source distributions as well as binary- however,
my binaries are built on a RH 7.0 Linuxsystem....and GNU changed the
glibc between 6.2 and 7.0 which makes things not backwards compatible
so that would abe a problem for you. Its too complicated to try to keep
machines running old OS versions here since we wouldn't be able to 
maintain improvements, bug fixes, security patches etc in the OS.

But if you are building from source, then you (or Bob) should just be able to 
relink your Garp using the change I mentioned (this is the same swicth
statement code as the $GEMPAK/source/driver/active/xw/xsatim.c source).

As for Nexrad Level III composites, I have created a program to
accomplish just that which I will be making part of my 5.6.B release. 
The general problem to overcome is re-projecting each radar from its site
specific projection into a common projection and handling the overlap from
adjacent stations. My program samples each radar onto a user defined grid
projection and stores the data as a GEMPAK grid file. I currently create
a US composite on grid #218, and a local 1km grid for my area.
I chose to store the data as a grid for the reason that you could then reproject
and overlay the data on imagery (which we can't do for proj=rad on proj=sat
images), and you can use the grids in computations with other grid fields from
models (such as the precipitation type mask for the RUC). Doing color filled
contours is a lillte slow for such large grids but otherwise, they look
good. I modified gdplot2 for a new TYPE value to speed up the plotting
by filling in the entire grid square (instead of contouring the data values).

You can download today's file from:
http://motherlode.ucar.edu/unidata/decoded/gempak/radar/20010228_radr.gem

To plot in gdplot2 as color filled contours:
 FINT     = 5/0
 FLINE    = 0;26-7
 TYPE     = f
 GDPFUN   = n0r
 GDATTIM  = last
 GLEVEL   = 0
 GVCORD   = none
etc.

Since this is under development, I'd welcome feedback.
When available, you will be able to create your own local mosaics
at whatever grid resolution you desire. The CONUS composite above
is roughly 3-4km resolution. 

Steve Chiswell
Unidata User Support



On Wed, 28 Feb 2001, Kevin Polston wrote:

> Hi Steve,
> 
> I am running NAWIPS5.6.A on a linux pc (running redhat linux 6.2).  I have 
> been
> downloading the program files from Bob R. from the SOOSAC FTP server.  I 
> believe
> there is some slight differences between the linux version and the hpux 
> version.
> Correct me if I am wrong but aren't you developing the hpux version and then 
> Bob
> works it into the linux version?  If this is true then I wouldn't be able to 
> test
> your binary...would I?
> 
> In any event I will give your suggestion a try about configuring GARP and see 
> what
> happens.
> 
> I also have a suggestion for you - although I don't know if it is possible.  
> Now
> that the NWS radar data is available I have been downloading it routinely and
> displaying it in both GARP and NSAT.  And it really is great however....it is 
> only
> for one station.  Is there any way possible to merge different radars of the 
> same
> data type (ie, base reflectivity, srm, etc) and create a composite product? 
> The way
> I am set up now I download anywhere from 8-12 radars from a specified region 
> and
> then can open up one radar in either GARP or NSAT.  Is that something you have
> considered already or could consider for 5.6.B?  To me it seems like it would 
> be a
> very technically challenging thing to do....but since companies like WSI and 
> UNISYS
> do it already I suppose there is a way. And even in AWIPS you can do it 
> although it
> seems a bit crude or rough around the edges. I am curious as to what it would 
> take
> to be able to do that and if you think that is possible in the near future.
> 
> I will e-mail you later tonight or tomorrow and let you know what happens 
> with GARP.
> Thanks for your help.
> 
> KP
> 
> 
> Steve Chiswell wrote:
> 
> > Kevin,
> >
> > I think the Garp problem exists where the developers of Garp copied over
> > their own version of a GEMPAK file and modified it for their uses-
> > unfortunately, that means it has to be edited separately to enjoy the
> > new features of GEMPAK (recall, Garp isn't part of GEMPAK).
> >
> > In: $GARPHOME/gempak/readimgdata.c, the switch ( imgtyp ) section
> > about line 107, needs an option:
> >           case IFNCDF:  /* NetCDF files */
> >
> >             crncdf ( filnam, &ier ) ;
> >             break;
> >
> > I will include that in my 5.6.B release in a few weeks.
> >
> > Are you building from source? Or have you downloaded a binary that I 
> > provided?
> > I can send you a binary if the latter is the case. Since I don't have any
> > NetCDF images to test on,it would be nice if I could test it out on
> > one of your images if you want me to send you a binary.
> >
> > Steve Chiswell
> > Unidata User Support
> >
> > On Wed, 28 Feb 2001, Kevin Polston wrote:
> >
> > > Hi Steve,
> > >
> > > I don't quite understand what is going on here. I am downloading and
> > > displaying netCDF satellite data with NSAT.  However....when I use GARP 
> > > and
> > > try to display a satellite image I get a blank screen with a map 
> > > background
> > > and at the bottom of the screen it says "No Image".  I don't understand 
> > > why
> > > that won't work in GARP.  Also, I noticed in NSAT that the netCDF images 
> > > won't
> > > zoom in like they did with the AREA files. Unfortunately, I cannot overlay
> > > other data when using NSAT like I can with GARP  - thus the reason why I 
> > > would
> > > like to be able to display the netCDF images in GARP.  If you have any 
> > > answers
> > > I would appreciate it. Thanks.
> > >
> > > KP
> > >
> > > Steve Chiswell wrote:
> > >
> > > > Kevin,
> > > >
> > > > The GEMPAK device drivers for XW, GF, GIF, TIF, PS are the
> > > > drivers that support the image display. Any program using those
> > > > devices can display the images.
> > > >
> > > > As I wrote below regarding NSAT:
> > > > > > You should be able to verify that GEMPAK can view your NetCDF files
> > > > > > by using
> > > > > > NSAT from the "FILE-->User_Defined" pulldown and browsing your
> > > > > > data directories for the data
> > > >
> > > > Steve Chiswell
> > > > Unidata User Support
> > > >
> > >
> > >
> 
>