[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Support #ZFI-856751]: Re: Offset Error w/default LAT/LON radar locations

Hi Ben-

> I look forward to hearing from them.
> 
> (and I err'd, I can't adjust KCXX in NexRad single scans, I was looking at the
> location for the range rings which I can adjust).

I found two references that agree with our location.  However, NCDC has
a slightly different longitude (-73:09:59):

http://mi3.ncdc.noaa.gov/mi3qry/identityGrid.cfm?fid=32963&PleaseWait=OK

so I will adjust that in the IDV station table.

How are you creating the KML/KMZ file?  Are you reprojecting to a lat/lon
projection before saving the image?  I created a display from KCXX, used
the Projection->Use Displayed Area to set the projection to lat/lon, 
added Range Rings and changed the location to CXX, set the spacing of the
rings to 1 km, zoomed in and saved it as the attached foo.kmz.  When I load 
that into
Google Earth, the center of the inner ring appears to be right over the
radar.  This was using the old position for CXX.

There is some roundoff when making the radar rings using the display projection,
but if you set the location with the station, it should be pretty spot on.

You can increase the displayed resolution of the lat/lon with the Preferences.
Go to the Edit->Preference menu and in the dialog, click the Formats & Data 
tab, and set the lat/lon format to be ##0.0##  (or add more # to the end for
more "precision").

Let me know how you are creating the KMZ file and we'll see if we can track
down what's going on.

Don Murray

> Tom Whittaker wrote:
> > Hi Ben....
> >
> > Nice to hear from you.  I am forwarding this along to Unidata, since
> > the location is contained in their resource file as:
> >
> > <station idn="000326" id="CXX" name="Burlington/Colchester" st="VT"
> > co="US" lat="44:30:40" lon="-73:10:01" elev="97"/>
> >
> > and I have no idea what the relationship is between this and the KMZ
> > file output....
> >
> > Don/Jeff/Yuan -- please write back directly to Ben (address@hidden)
> >
> > tom
> >
> >
> > On Tue, Feb 3, 2009 at 12:07 PM, Ben Kamen <address@hidden> wrote:
> >> Hey Tom,
> >>
> >>  I thought I would bring to your attention a little thing we noticed I'm
> >> guessing is a rounding error in IDV.
> >>
> >>
> >> If you recall, you helped me with making that Jython script to average
> >> multi-selected L2 radar data and I've noticed when I output to KMZ, that
> >> KCXX is way off center from where google earth thinks it is (based on the
> >> KML data file you can get from NOAA with waypoints on the stations which 
> >> are
> >> pretty spot-on.)
> >>
> >> I can normally adjust this if I loaded a single scan, but when I pile the
> >> scans with the average, I can no longer adjust where IDV thinks KCXX is
> >> located (which the normal method shows KCXX LAT/LON with only dd.m rez. 
> >> Thus
> >> the rounding error).
> >>
> >> Is there a datafile we can edit this or is it needing to be done elsewhere?
> >>
> >> Thanks,
> >>
> >>  -Ben
> >>
> >>
> >
> >
> >
> 
> --
> Ben Kamen - O.D.T., S.P.
> =============================================================================
> Email: bkamen AT benjammin DOT net              Web: http://www.benjammin.net
> 
> As seen somewhere on the net: My other computer is your Windows Server.
> 
> 


Ticket Details
===================
Ticket ID: ZFI-856751
Department: Support
Priority: Normal
Status: Open