Multi-level Station Data

[Random Person]

GrADS Users,
I cannot seem to figure out how to properly use
multi-level station data in GrADS.  I've read all I
can find in the listserv archive and have not yet
found something that seems to solve my problem.  I'm
able to create single-level station files and interact
with them in GrADS.  I can also create station files
with both single-level and multi-level variables and
interact with any of the single-level variables but I
cannot interact with the multi-level variables. I'm
not sure if my problem is that I'm not properly
interacting with the multi-level variables or if I'm
not properly writing the multi-level variables to the
data file in the first place.

Based on an example I found in the listserv archive,
to test if the multi-level variables are recognized by
GrADS I issue the following commands:
set gxout stat
set stnprint on
d a
where 'a' is the name of the multilevel variable.
This results in the following output:

Data Type = station
Dimensions = 0 1
I Dimension = 0 to 360
J Dimension = -90 to 90
Stn count = 0
Undef value = -999
Undef count = 0  Valid count = 0
Min, Max = -999 -999
Cmin, cmax, cint = -1004 -994 1
Stats[sum,sumsqr,root(sumsqr),n]:     0 0 0 0
Stats[(sum,sumsqr,root(sumsqr))/n)]:     0 0 0
Stats[(sum,sumsqr,root(sumsqr))/(n-1))]: 0 0 0
Stats[(sigma,var)(n)]:     0 0
Stats[(sigma,var)(n-1)]:   0 0
Printing station values:  #obs = 1
OB    ID       LON      LAT      LEV      VAL

I assume this means that it cannot 'see' the
multi-level data since when I issue
a similar set a commands for a single-level variable
it lists output that ends with the ob ID's, lon, lat,
level, and value.  Assuming that this is a valid
way to test that a multi-level variable is 'seen' by
GrADS, it would seem that I have not correctly created
the data file or ctl file.

The version of GrADS I'm using is v1.9b4 (the
Intel/LinuxRHE3 binaries).

I created the data file with the following Fortran 90
code:
*******************************************
PROGRAM TESTCASE
   IMPLICIT NONE
   integer :: outunit = 12 !Output file unit
   character(len=8) :: stationid !Station identifier
for grads file
   real :: lat,lon !Latitude, longitude
   real :: timeshift !Time shift of this ob
   integer :: nlev !Number of vertical layers (+1 if
flag==1)
   integer :: flag !Is there sfc-only data
   real :: height !Height of ob
   real :: ob !Observed value


   !Open the output file

open(outunit,file='testcase.dat',status='replace',action='write',&
    form='unformatted',access='sequential')

   write(stationid,'I8'),1
   lat = 45.0
   lon = 35.0
   timeshift = 0.0
   nlev = 2
   flag = 0

   !Write header

write(outunit),stationid,lat,lon,timeshift,nlev,flag


   !Write data for first layer
   height = 15.0
   ob = 12.0
   write(outunit),height,ob

   !Write data for second layer
   height = 25.0
   ob = 22.0
   write(outunit),height,ob

   !Write time terminator
   write(outunit),'TIMETERM',0.0,0.0,0.0,0,0

   close(outunit)

END PROGRAM TESTCASE
*******************************************

My ctl file is as follows:
*******************************************
DSET   ^testcase.dat
DTYPE  station
STNMAP testcase.map
UNDEF  -999.0
TITLE  Test Data
OPTIONS sequential
TDEF    1 linear 00:00Z01may2002 01mn
VARS    1
a 1 99 no description
ENDVARS
*******************************************

For simplicity, this test case is basically a single
variable at a single time with two levels.
Running stnmap I get the following result:
*******************************************
  Name of binary data set: testcase.dat
  Number of times in the data set: 1
  Number of surface variables: 0
  Number of level dependent variables: 1

Starting scan of station data binary file.
Binary data file open: testcase.dat
Processing time = 1
  ID,LON,LAT,T,NLEV,FLAG:        1 35 45 0 2 0  SIZE =
44
  ID,LON,LAT,T,NLEV,FLAG: TIMETERM 0 0 0 0 0  SIZE =
28
     Time = 1 has stn count = 1
  Max reports per time:  1 reports at t = 1
  Max data elements in largest report: 4

Version 2 Station map file created: testcase.map

stnmap: WARNING!!  This stnmap file can only be
accessed by GrADS Version 1.9b4
stnmap: WARNING!!  However, GrADS Version 1.9b4 can
read both versions

stnmap: COMMENT  -- use the -1 command line option to
create a map for older GrADS versions

stnmap: COMMENT  -- use the -q command line option to
disable the station header listing
*******************************************

I have run other test cases that vary the number of
times, the number of stations, and the number of
variables and invariably I obtain the same results.
All of the single-level variables appear correct while
I am unable to get themulti-level data to show up.
Perhaps this means that the process I'm using to check
if the multi-level data is there is incorrect?

I would appreciate any help anyone could offer.

Thanks,
Brian Reen


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