RFI alert for Sep 2011

  11.09.15  R 15Sep    23h12    22h15-01h15 AST  = 16 Sep 02h15-05h15 UTC  conflict first 45 min
  11.09.16  F 16Sep    23h16    22h15-04h00 AST  = 17 Sep 02h15-08h00 UTC

  Hence there is a conflict with A2010 during the period
  20110916  0215-0515 UTC

Message received 
Subject: GPS-L3 (1381 MHz)  RFI Alert
Date: Wed, 31 Aug 2011 11:13:03 -0600
From: Dan Mertely 
-----------------------------------------------------------------
We have received recent notice from the US Space Command
(USSC), Colorado Springs, CO, informing the RA community of
upcoming, extended L3 test transmissions.  The observatories
should expect increased RFI @ 1381 MHz during the dates &
times indicated below.  No specific cause was released.

VLA & VLBA schedulers should attempt to schedule 1381 MHz use
around these times if possible.  Observing scientists should
be made aware of the increased possibility of corrupted data
on these dates and times.  VLA and VLBA operators should note
unusual L-band Tsys or total power fluctuations observed during
these times in the Operator Log forwarded to observers.

A more detailed schedule will be provided as soon as additional
information is made available from USSC (call pending).

(It should be noted as well that the new GPS Block IIF satellites
include L5 capability, which broadcasts a CDMA (wide banded)
signal at 1176.45 MHz.  The L5 signal, which is stronger and
wider than the GPS L1 & L2 CDMA signals, is continuously
broadcast, and will be used for aircraft navigation.  GPS IIF-1
has been up and broadcasting the L5 signal since 20100628.
All subsequent GPS satellites will have this capability.  We
have seen the L5 transmissions here on our VLA RFI monitoring
systems.)

-Mert


123456789012345678901234567890123456789012345678901234567890
         1         2         3         4         5         6
============================================================
GPS-L3 ALERT SCHEDULE:
============================================================
SUBJECT:  Extended GPS Satellite Testing Operations (SVN-63?).

FREQUENCY AFFECTED:    1381.05 ± 2.5 MHz

DATE (UTC)  TIME (UTC)    Comments
(YYYYMMDD)  (HHMM)-(HHMM) (TEXT)
------------------------------------------------------------
20110913     1900 - 2400   Intermittent L3 tests, world-wide.
20110914     0000 - 0300   Intermittent L3 tests, world-wide.

20110914     1900 - 2400   Intermittent L3 tests, world-wide.
20110915     0000 - 0300   Intermittent L3 tests, world-wide.

20110915     1900 - 2400   Intermittent L3 tests, world-wide.
20110916     0000 - 0300   Intermittent L3 tests, world-wide.
================================================================
# * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # *
* # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * #
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
From the clear, high deserts of central New Mexico, The Land of
Enchantment, the VLA, and dark, dark, starry, starry nights ...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* # * # * # * # * # * # * # * # * # * # * # * # * # * # * # * #
# * # * # * # * # * # * # * # * # * # * # * # * # * # * # * # *

Daniel J. Mertely
National Radio Astronomy Observatory
Interference Protection Office Engineer
P.O. Box o
Socorro,  NM  87801
(575) 835-7128
dmertely@nrao.edu

-Mert