Problems in displaying netCDF files with GrADS

[Fred Yongxin Zhang]

Dear GrADS users,

   I tried displaying netCDF files with GrADS v1.8SL9 but I encountered
some problems. Please refer to the attached information. I searched the
online archive but did not find solutions to these problems. Your
suggestions are greatly appreciated.

Thanks,
Fred

***************Return from "ncdump -h" is as follows***************
netcdf 20041030_1030 {
dimensions:
        y = 512 ;
        x = 1024 ;

variables:
        byte image(y, x) ;
        double validTime ;
                validTime:units = "seconds since 1970-1-1 00:00:00.00
0:00" ;
                validTime:long_name = "Valid Time" ;
        byte valid100thSecs ;
                valid100thSecs:units = "centiseconds" ;
                valid100thSecs:long_name = "Valid 100th of a second" ;

// global attributes:
                :channel = "Visible" ;
                :depictorName = "nh2Sat at 18316368" ;
                :projIndex = 1 ;
                :projName = "STEREOGRAPHIC" ;
                :centralLat = 90.f ;
                :centralLon = -105.f ;
                :rotation = 0.f ;
                :xMin = -1.0335739f ;
                :xMax = 1.0335791f ;
                :yMin = -1.0335739f ;
                :yMax = 0.f ;
                :lat00 = -1.8917102f ;
                :lon00 = 165.f ;
                :latNxNy = -21.245136f ;
                :lonNxNy = -59.999855f ;
                :dxKm = 20.313013f ;
                :dyKm = 20.332838f ;
                :latDxDy = 35.341339f ;
                :lonDxDy = -104.99971f ;
}

*********************My data descriptor file looks like this**********
dset ^20041030_1030
title This file contains the satellite data
undef 99999.0
xdef x 1024 LINEAR 0.0 .25
ydef y 512 LINEAR 0.0 .25
vars 1
image=>image 0 512 1024 satellite data
endvars

********************The error message looks like this******************
ga-> xdfopen 20041030_1030.ctl
Scanning Descriptor File:  20041030_1030.ctl
SDF file has no discernable time coordinate.
Found displayable variable image with 0 levels in SDF file.
Data file 20041030_1030 is open as file 1
LON set to 0 255.75
LAT set to 0 127.75
LEV set to 0 0
Time values set: 1:1:1:0 1:1:1:0
ga-> d image
SDF data variable has unsupported packed data type.
Data Request Error:  Error for variable 'image'
  Error ocurred at column 1
DISPLAY error:  Invalid expression
  Expression = image
ga->
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