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20051111: a question about flight track

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  • Subject: 20051111: a question about flight track
  • Date: Fri, 11 Nov 2005 12:37:53 -0700
>From: "Qun Miao" <address@hidden>
>Organization: University of Wyoming
>Keywords: 200511111828.jABISs7s019837 IDV flight track

Hi-

>I am wondering if there is a way to overlay a flight track on a radar =
>image in IDV. If the answer is yes, that'll be great and I have the =
>following question about track files.
>
>I tried to create a NetCDF file as a track file. It's like this,
>
>netcdf test1 {
>dimensions:
>        time = 3 ;
>variables:
>        double time(time) ;
>                time:long_name = "Time" ;
>                time:unit = "sec" ;
>        float altitude(time) ;
>                altitude:long_name = "Altitude" ;
>                altitude:unit = "meter" ;
>        float latitude(time) ;
>                latitude:long_name = "Latitude" ;
>                latitude:unit = "degree north" ;
>        float longitude(time) ;
>                longitude:long_name = "Longitude" ;
>                longitude:unit = "degree east" ;
>}.
>
>But IDV can't load it as a track file.

The problem is that the unit specifications are not correct
for this file.  The correct attribute should be "units"
instead of "unit" and they value should either be just
"degrees" or "degrees_north" and "degrees_east" for
latitude and longitude respectively.

>Looking forward to your response. And thanks in advance.

I also suggest that you specify something like
"seconds since 2004-06-21 00:00:00 00:00" (use whatever
time the flight started) for time.  If you just have seconds, it
will take it as seconds since 1970-01-01 00:00:00.

Don Murray
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