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20050105: IDV - Flight Track File in IDV 1.2b1

>From: "Greg Salottolo" <address@hidden>
>Organization: NTSB
>Keywords: 200501051815.j05IFvGr025053 IDV track

Hi Greg-

>Institution: NTSB
>Package Version: 1.2b1
>Operating System: os.name:Windows XP; os.arch:x86; os.version:5.1; 
>Hardware Information: java.vendor:Sun Microsystems Inc.; java.version:1.4.2_01
> ; java.home:C:\\Program Files\\IDV_1.2b1\\jre; 
>Inquiry: Good Afternoon:
>
>I am not having much luck trying to find out how to generate a flight track fi
> le (lat/lon/alt) that can be imported and displayed in IDV. Can you offer som
> e
>suggestions?

You'd need a netCDF file of the form:

netcdf UnidataTestFileMN {
dimensions:
        time = UNLIMITED ; // (229 currently)
variables:
        int time(time) ;
                time:units = "seconds since 2002-10-25 0:00:00 0:00" ;
                time:long_name = "Time offset from base_time" ;
                time:_FillValue = -99999 ;
                time:missing_value = -99999 ;
        float altitude(time) ;
                altitude:units = "km" ;
                altitude:long_name = "altitude MSL" ;
                altitude:_FillValue = -99999.f ;
                altitude:missing_value = -99999.f ;
        float latitude(time) ;
                latitude:units = "degrees_N" ;
                latitude:long_name = "north latitude" ;
                latitude:valid_range = -90.f, 90.f ;
                latitude:missing_value = -99999.f ;
                latitude:_FillValue = -99999.f ;
        float longitude(time) ;
                longitude:units = "degrees_E" ;
                longitude:long_name = "east longitude" ;
                longitude:valid_range = -180.f, 180.f ;
                longitude:missing_value = -99999.f ;
                longitude:_FillValue = -99999.f ;

(I got this file from either you or Grant Petty).

From the File Chooser, set the Data Source Type to be a Track file,
select the file you want to display and click Add Source.

In the Data Selector, you should see a Track tab and a
Point Display field in the Fields pane.  Expand the
Track tab and select one of the fields (e.g. Latitude).
In the Displays pane, select "Track colored by Parameter", then
click the "Create Display" button.  That should
create the display of the track.

Now, if you want to see an airplane in your display for the
craft's position, do the following.  From the Data Selector
window, select the Point Display Field and the Point Data Plot
display, then click Create Display.  From the Point Display's
control window, click on the little edit icon (paper and pencil)
on the right of the Change button to bring up the Station
Model Editor (this will change to Point Data Plot editor
probably in a future release).  From the editor's File menu,
select the New menu.  In the dialog, type in a name for
this model (e.g. Airplane).  Now, click on the Shape item
in the list of objects, then click on the middle of the
editing canvas (white panel with cross).  This will place
a shape on the canvas. Right click on the shape and use
the Center->Center menu to center the shape on the display point
(lat/lon/alt).  Right click again and bring up the
Properties dialog.  In the Display tab, select the type of
shape you want to put at each point (e.g. 3-D Airplane).  Click
on the OK button.  Now, in your Point Display Control window,
click the Change button and select your new model from the
list.  You should see the airplane in the main display.  Turn 
on the animation and watch it move with time.  You can speed up 
the animation using the animation control ("i" icon on the 
animation control bar).

Bring up the Station Model Editor again and bring up the
Properties dialog.  Click on the Rotate By tab.  For the
Rotate By Parameter field, type in "Direction".  (I calculate
a heading based on the difference between the lat/lon points.
If you have a heading parameter in the file, use that name
instead).  For the Data Range, set the range to be 0 to 360.
Leave the unit as Default.  Leave the Degrees as 0 and 360.
Now click OK.  As the plane flies along the track, it will
be rotated by the directional heading. (Sorry this isn't
really documented).

That should get you going.  You can create different station
models depending on what you want to display.  For example,
you could add in a value glyph to plot the lat/lon/alt at
each point.  See:

http://my.unidata.ucar.edu/content/software/idv/docs/userguide/tools/StationModelEditor.html

in the User's Guide for more info (or Help->User's Guide menu and
then the Tools->Station Plot Model Editor section in the IDV).
That is left as a simple exercise to the reader. ;-)

Enjoy.

Don Murray
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