[McIDAS #QRJ-934735]: LEODATA

["Unidata McIDAS Support" <support-mcidas@xxxxxxxxxxxxxxxx>]

Hi Robert,

re:
> Sorry it has taken a while to get back to you.

No worries.

> Our northern Sweden to Canada
> campaign ended unexpectedly quickly..unusually good weather for Spring/early
> summer in northern Sweden, so I did not need this data by the time the
> addendum was ready.  It will be most helpful though over the next 2 years.

Very good.  I got LEO to work after a bunch of code diving and playing
around.  See below...

> I am out in New Mexico right now and have just finished upgrading our server
> and workstation to the latest version.  Can you give me more info on what I
> need to do to download the two elements referenced and create the POESNAV
> dataset?

I found that current two line elements for TIROS and the set of NOAA polar
orbiters can be found at:

http://www.oso.noaa.gov/poes/
  Click on 'NORAD two-line element sets'

This pops up a new browser window/tab in which is listed the two line elements
(TLE) for TIROS N and NOAA 1 - NOAA 19.  Cut all of those values out, and save
them in a file in your $MCDATA directory.  I called the file NORAD.TLE.
Alternately, you could separate the two line element entries into individual
files, say one for NOAA 16, a different one for NOAA 17, etc.  If you
decide to go with separate files, you will need to create separate ADDE
datasets from each.

You will need to edit the values in that file to remove the space between the
satellite family name and series.  For example, change the entry for NOAA 18:

change:

NOAA 18 [+]              
1 28654U 05018A   09238.37737062  .00000013  00000-0  31764-4 0   211
2 28654  98.9104 181.0848 0014575 161.1915 198.9797 14.11280796219858

to:

NOAA18 [+]              
1 28654U 05018A   09238.37737062  .00000013  00000-0  31764-4 0   211
2 28654  98.9104 181.0848 0014575 161.1915 198.9797 14.11280796219858

Comment:

The need to remove the space is dictated by the way that the NAVSET NAMES=
values are parsed from the LEODATA.(CORE|SITE|USER) files: you can not
specify a NAVSET NAMES= dataset with a space in it:

NAVSET      NAMES= NORAD/'NOAA 15'     <- not legal

This is not surprising given that ADDE dataset group and descriptor names
can not have embedded spaces.

The descriptor portions of the NAVSET NAMES=  entries are used in NAVCALC
invocations as the 'sat' value portion of the TYPE=T 'sat' keyword.
This value is then use to see if there is an exact match with an entry in
the ADDE TLE dataset.

Back to the procedure:

Next, create the ADDE TEXT dataset using the file you just created and edited.
For example:

DSSERVE ADD NORAD/TLE TEXT INFO=NORAD.TLE "NORAD TLE definitions for TIROS and 
NOAA Polar Orbiters

Next, make a local copy of LEODATA.CORE as $MCDATA/LEODATA.USER
(or ~mcidas/data/LEODATA.SITE) and edit the file to include the set of
polar orbiters you want to be used by LEO.  I have attached the simple version
of LEODATA.USER that I put together for testing; it only contains
entries for NOAA 15-18.

Finally, try running LEO.  Here are a couple of LEO invocations I tried
with success:

LEO EUROPE IR DAY=239 TIME=20
LEO SAMERICA IR DAY=239 TIME=20
LEO HAWAII IR
LEO AUSTRALIA IR

Additional comments:

- I believe, but am not sure, that you can add new TLE elements to the
  end of the file(s) you created in one of the steps described above.

- You may need to play with the TIME keyword to get coverage over
  a specific area (not surprising given that we are talking about
  polar orbiter data)

- the seams between different passes/satellites can be ugly at times

Cheers,

Tom
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Ticket Details
===================
Ticket ID: QRJ-934735
Department: Support McIDAS
Priority: Normal
Status: Closed

Attachment: LEODATA.USER
Description: Binary data