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Brian, The ltgmap program was the same program as sfmap. It just allowed a greater number of times/observations. In GEMPAK 5.6, I increased the number of times/observations in sfmap so that a separate ltgmap program wasn't needed. The lat/lon locations are the station locations (each lightning strike is treated as a "ship" report). I can create a program in the next few days that will read the surface file and create the grid of "reports within a DELTA radius". Steve Chiswell Unidata User SUpport >From: Brian Colle <address@hidden> >Organization: UCAR/Unidata >Keywords: 200110222134.f9MLY8102451 > >Steve, > >> >> Brian, >> >> At this point in time, there is nothing within GEMPAK >> to make this type of computation as you require. >> >> I would be possible to write a program to accumulate the number >> of strikes within a given radius of a grid point. >> > >In order to write another program I need to know how to open and >read the ltg sfc file to extract the lat/longs for each lightning strike, >assuming that they are stored that way. Just to clarify, is there a gempak >fortran subroutine that will read the file and extract this information? >For example, I used to use ltgmap, which plotted the individual lightning >strikes. I was hoping that I could take advantage of the way ltgmap reads >in the data, but only use the lat/long info. I notice that the latest >version of gempak doesn't even use ltgmap anymore? > >> The other limitation you would have is that a 3km grid is going >> to be a very large grid if you are attempting to cover the >> entire country with a single grid. At present time, the default >> maximum number of grid points in a file is 400,000. >> A 4km national grid is approximately 1,200,000 points. >> >> If you are doing a regional (or series of regional) grids >> then that won't be a problem. >> > >Yes, I only want the regional NE US. > >Thanks again, > >Brian > >> > >> >Hi, >> > >> >I have some gempak lightning data (surface files of sgnl strength) that I >> >want to interpolate to a uniformly spaced 3-km gempak grid such that each >> >grid point has the number of nearby strikes. With this gridded file I can >> >then contour the number density up in gempak. >> > >> >Do you have any ideas or sample code how I can do this interpolation >> >of lightning data within gempak or interfacing gempak with f77? >> > >> >I appologize in advance for the loaded question, but I am looking >> >for ideas at this point. >> > >> >Thanks for your time... >> > >> >Brian >> >____________________________________________________________ >> >Prof. Brian Colle INTERNET: address@hidden >> >(631)632-3174 >> >Institute for Terrestrial and Planetary Atmospheres >> >Marine Sciences Research Center >> >State University of New York at Stony Brook >> >Stony Brook, NY 11794-5000 >> > >> >> **************************************************************************** >> Unidata User Support UCAR Unidata Program >> (303)497-8644 P.O. Box 3000 >> address@hidden Boulder, CO 80307 >> ---------------------------------------------------------------------------- >> Unidata WWW Service http://www.unidata.ucar.edu/ >> **************************************************************************** >> >