RFI alert Mar 2008

1900-0300 UT = 1500-2300 AST on Mar 3-7, 2008

UPDATE FROM MURRAY:

Riccardo, Martha

The GPS active days are on you, as per my last advice forwarded from Mert.
That said they were starting an hour earlier.  That commitment, together
With the undertaking Mert received earlier (attached below), suggests you
should be free of GPS in your time frame for observations in early March.
Wopuld you leet me know the actual status over these days - in effect has
coordination at 1381 MHz succeeded this time.

Cheers,

Murray


------ Forwarded Message
From: Dan Mertely 
Organization: NRAO
Date: Thu, 21 Feb 2008 11:35:04 -0700
To: Tom Gergely , Andy Clegg 
Cc: Murray Lewis , Dan Mertely ,
rkerr@naic.edu, Bob Brown , Harvey Liszt

Subject: Re: Arecibo GPS coordination for March - 3rd

Tom/Andy:

I have discussed the problem with Murray, and with the GPS L3
control.  The USAF will keep the bulk of their March 4, 5, & 6
RZAP/LZAP test transmissions confined to pre 00:00 UTC each day.
Murray has indicated that this is a reasonable compromise.

I am now coordinating the new RZAP/LZAP alert tentatively scheduled
for March 31 - April 2, and the preliminary March 24 - 28 new SV
on-orbit test.  We'll see if they are able to push these 2 tests
out beyond April 4th, so as to avoid deleterious effects to the
ALFALFA project observing of March.

--------------------------------------
ORIGINAL ALERT:

We have been alerted to the following, military GPS-L3 test
Transmissions which may cause RFI to observations scheduled for the
use of L-band (21cm) on the UTC date(s) and time(s) listed below.
These tests are part of the pre-scheduled, quarterly L3 test
activations.

The 1381 MHz frequency is within the VLA L-band 21/20cm "LL"/"21",
"L1", and "L2", continuum default frequencies, and any L-band
spectral line set-up that includes 1381.05 ± 2.5 MHz.

Please be sure to include the date, time, and frequency of any
RFI shown below with your A2010 log.
Thanks!

-----------------------------------------------------------------------

Notification of GPS L3 RFI world-wide

SUBJECT:  GPS Satellite Testing Operations.

FREQUENCIE(S) AFFECTED:    1381.05 +/- 2.5 MHz

DATE (UTC)   TIME (UTC)      Comments
(YYYYMMDD)   (HHMM)-(HHMM)   (TEXT)
----------------------------------------------------------------------
20080304     1900 - 2400     2Q 2008 RZAP/LZAP system-wide tests.
20080305     0000 - 0300     2Q 2008 RZAP/LZAP system-wide tests.
20080305     1900 - 2400     2Q 2008 RZAP/LZAP Back-up date.
20080306     0000 - 0300     2Q 2008 RZAP/LZAP Back-up date.
20080306     1900 - 2400     2Q 2008 RZAP/LZAP Back-up date.
20080307     0000 - 0300     2Q 2008 RZAP/LZAP Back-up date.
======================================================================

EARLY NOTICE:  GPS control indicates the likely on-orbit tests of
the L3 systems on the new, GPS 2R-19 (M6) satellite starting 20 March,
2008.  (This assumes the current launch forecast of 15 March, 2008.)
Test time window is tentatively set to 0245-0930z.  Updates will be
forwarded as their schedule becomes more firm.

======================================================================

EARLY NOTICE:  GPS control has scheduled-in a 2nd RZAP/LAZAP test for
31 March through 2 April.  Exact times TBD.  We are working with them
to delay past April 4th at the request of Arecibo.  Updates will be
forwarded as their schedule becomes more firm.

Old RFI alerts

• Mar 2007 GPS alert
• Dec 2006 GPS alert
• Oct 2006 GPS alert