Re: [ldm-users] uniwisc feed receive times

Hi Dave,

The timestamp of the image is the time that the scan began.  There are many 
different scanning strategies and regions, and each of them takes a different 
amount of time to complete.

Speculating that the routine schedule was in place for yesterday, and using 
this resource 
http://www.ospo.noaa.gov/Operations/GOES/east/imager-routine.html, I see that a 
typical 1345 UTC image would be the Northern Hemisphere Extended sector, which 
takes 14:15 (14.25 minutes) to complete.  This image did not complete until 
13:59:15.  I do not know the magic that occurs to bring the images into the LDM 
IDD feed, but there is much less latency than you might think there is given 
the time to conduct the sector scan.  A full disk image, done every three hours 
for WMO data sharing, takes 26:02.

We have a NOAAPort ingest system, so we get some data that way.  Those images 
are first downloaded to Wallops Island, and then bounce around through some 
absurd number of miles to get to our dish.  (I really do not know enough about 
this to say any more, and may have already stepped outside of an accurate 
description.)

I hope this helps,
Chris H.

--

Dr. Christopher G. Herbster
Associate Professor
Director of Science and Technology
for the ERAU Weather Center
Applied Aviation Sciences
Embry-Riddle Aeronautical Univ.
600 S. Clyde Morris Blvd.
Daytona Beach, FL 32114-3900
 386.226.6444 Office
386.226.6446 Weather Center
http://wx.erau.edu/

Schedule at:  http://wx.erau.edu/faculty/herbster/Schedules/

From: ldm-users-bounces@xxxxxxxxxxxxxxxx 
[mailto:ldm-users-bounces@xxxxxxxxxxxxxxxx] On Behalf Of David Fitzgerald
Sent: Tuesday, March 28, 2017 12:27 PM
To: 'ldm-users@xxxxxxxxxxxxxxxx' <ldm-users@xxxxxxxxxxxxxxxx>
Subject: [ldm-users] uniwisc feed receive times

Hi Everyone,

We have noticed that our UNIWISC feeds seem to be running up to 30 minutes 
behind the product creation time.  Our weather station people are annoyed the 
imagery is so late.

For example, the line shown below is from an `ldmadmin watch -f UNIWISC` 
command showing a GOES-13 image:

20170328T141114.365590Z pqutil[29006] INFO pqutil.c:1181:display_watch()     
741505 20170328141111.455496 UNIWISC 000  pnga2area Q3 UE 1231 GOES-13_IMG 
13.3um 4km 20170328 1345

This shows we got the image at 1411, and was sent to us from our upstream site 
only a few seconds earlier.  But the image time is for 1345.

Is anyone else seeing this, and is this a normal lag between image creation and 
dissemination?

Dave

++++++++++++++++++++++++++++++
David Fitzgerald
Information Technology
Millersville University
Millersville, PA 17551

Phone:  717-871-7436
E-Mail:  
david.fitzgerald@xxxxxxxxxxxxxxxx<mailto:david.fitzgerald@xxxxxxxxxxxxxxxx>