Re: [idvusers] aircraft track data

• To: Sebastian Engelstaedter <sebastian.engelstaedter@xxxxxxxxxxxxx>
• Subject: Re: [idvusers] aircraft track data
• From: "Larry D. Oolman" <ldoolman@xxxxxxxx>
• Date: Sun, 10 Apr 2011 22:23:52 -0600

Are you generating the data file or getting it from someone else?
The sps01 dimensions suggests that the file may be trying to be
in NCAR_RAF/nimbus conventions.  This convention is defined in
http://www.eol.ucar.edu/raf/Software/netCDF.html

This convention was developed at NCAR in the 1990s.  It is also
used by the University of Wyoming King Air.  Support in
IDV was added during a field project in 2006.

My guess is that the global attribute: ':coordinates' is missing.
This is used to tell the software what variables to use for
longitude, latitude, altitude, and time.  NCAR is moving towards
using different attributes but ':coordinates' was used when
IDV was adapted to these file.  If you want to send me a full
file, I can take a look and see what may be amiss.

Sebastian Engelstaedter wrote:

Hi all,

I am new to IDV but it looks like a powerful tool. I want to plot aircraft track data which come in netCDF format. However, IDV is unable to read in the current netcdf file I have. Can someone point me to the correct format. At the moment the netcdf file looks something like this:

dimensions:
         data_point = UNLIMITED ; // (28980 currently)
         sps01 = 1 ;
variables:
         int Time(data_point) ;
                 Time:long_name = "time of measurement" ;
                 Time:units = "seconds since 2011-04-04 00:00:00 +0000" ;
                 Time:_FillValue = -1 ;
                 Time:standard_name = "time" ;
         float IAS_RVSM(data_point, sps01) ;

IAS_RVSM:long_name = "Indicated air speed from the aircraft RVSM (air data) system. " ;

                 IAS_RVSM:units = "m s-1         " ;
                 IAS_RVSM:_FillValue = -9999.f ;
                 IAS_RVSM:Frequency = 1s ;
                 IAS_RVSM:Number = 516s ;
         byte IAS_RVSM_FLAG(data_point, sps01) ;

IAS_RVSM_FLAG:long_name = "Flag for Indicated air speed from the aircraft RVSM (air data) system. " ;

                 IAS_RVSM_FLAG:units = 1s ;
                 IAS_RVSM_FLAG:_FillValue = -1b ;
                 IAS_RVSM_FLAG:Frequency = 1s ;
         float TAS_RVSM(data_point, sps01) ;

TAS_RVSM:long_name = "True air speed from the aircraft RVSM (air data) system and deiced temperature. " ;

                 TAS_RVSM:units = "m s-1         " ;
                 TAS_RVSM:_FillValue = -9999.f ;
                 TAS_RVSM:Frequency = 1s ;
                 TAS_RVSM:Number = 517s ;
                 TAS_RVSM:standard_name = "platform_speed_wrt_air" ;
         byte TAS_RVSM_FLAG(data_point, sps01) ;

TAS_RVSM_FLAG:long_name = "Flag for True air speed from the aircraft RVSM (air data) system and deiced temperature. " ;

                 TAS_RVSM_FLAG:units = 1s ;
                 TAS_RVSM_FLAG:_FillValue = -1b ;
                 TAS_RVSM_FLAG:Frequency = 1s ;
         float TAT_DI_R(data_point, sps01) ;

TAT_DI_R:long_name = "True air temperature from the Rosemount deiced temperature sensor. " ;

                 TAT_DI_R:units = "degK          " ;
                 TAT_DI_R:_FillValue = -9999.f ;
                 TAT_DI_R:Frequency = 1s ;
                 TAT_DI_R:Number = 520s ;
                 TAT_DI_R:standard_name = "air_temperature" ;
....




Any help is much appreciated.

Best wishes,
Sebastian

--
Larry Oolman
Department of Atmospheric Science
University of Wyoming
Dept. 3038, 1000 E. University Ave.
Laramie, WY 82071
ldoolman@xxxxxxxx
http://www-das.uwyo.edu

• References:
  • [idvusers] aircraft track data
    • From: Sebastian Engelstaedter