Stonie,
For the GRB satellite data feed - currently GOES East/16 products come through
looking something like
/data/cspp-geo/GRB-R/OR_ABI-L1b-RadM1-M6C11_G16_s20250642015250_e20250642015307_c20250642015351.nc
/data/cspp-geo/GRB-R/OR_SEIS-L1b-MPSL_G16_s20250642013300_e20250642013590_c20250642014002.nc
Will this change other than changing G16 to G19 and maybe GRB-R to GRB-U (I
think that's what G19 was..)
I know at one point there was talk of changing 'GRB-R' to 'EAST' - which was
done for the GOES-West GRB already, like
/data/cspp-geo/WEST/OR_ABI-L1b-RadM1-M6C03_G18_s20250642015252_e20250642015309_c20250642015337.nc
Thanks for the heads-up!
Pete
Pete Pokrandt - System Engineer IV
UW-Madison Dept of Atmospheric and Oceanic Sciences
608-262-3086 - poker@xxxxxxxxxxxx
________________________________
From: ldm-users <ldm-users-bounces@xxxxxxxxxxxxxxxx> on behalf of Stonie Cooper
<cooper@xxxxxxxx>
Sent: Wednesday, March 5, 2025 1:39 PM
To: LDM <ldm-users@xxxxxxxxxxxxxxxx>; NOAAPORT <noaaport@xxxxxxxxxxxxxxxx>
Subject: [ldm-users] GRB specific information.
If you don't operate or care about GRB ground station operations, please just
hit delete. For those that operate a GRB ground station, here is some
important information from Toby Hutchings with NESDIS on the upcoming roll-out
of GOES 19 into operations:
Greetings User Community,
Broadcasting answers to frequently asked questions to the community. Below you
will find the latest topic of discussion.
Is there an expectation that some GRB users may need to re-point their antennas
in connection with the G16 "nudge", and then re-point again for the transition
to G19 GRB? If so they might like to know the specific date of the nudge.
"Short answer: Assuming GRB users are operating an antenna 7m or smaller, they
should not have to re-point their antennas during the G16 to G19 transition.
Longer answer: GOES 16 is being nudged from 75.2 deg W to 75.5 deg W.
Using our HR5 antenna here at WCDAS as a reference, the difference in ground
antenna pointing angles between these two orbit locations is as follows:
HR5 - GOES 16 (75.2 deg) = 179.50 deg AZ and 44.95 deg EL
HR5 - GOES 16 (75.5 deg) = 180.06 deg AZ and 44.85 deg EL
The difference in ground antenna pointing angles is 0.47 deg AZ and 0.1 deg EL
Assuming a GRB user is operating a 7 meter antenna, the half-beam width
calculations of that antenna at 1.686 GHz is as follows:
0.25 deg = 0.25 dB
0.35 deg = 0.5 dB
0.5 deg = 1 dB
0.86 deg = 3 dB
Since the expected pointing angle offsets are 0.47 deg AZ and 0.1 deg EL, the
expected downlink degradation should be between 0.5 and 1 dB. This expected
degradation should not cause an issue with users assuming that their antennas
are peaked on G16 at its current location. If they are not peaked currently,
this move and resulting degradation could cause issues.
Additionally, any users with antennas larger than 7m will have narrower beam
widths and thus experience a greater signal drop from this move. For example,
if our 16.4m HR antennas were not autotracking, we would experience a 6dB drop
in signal from this move if we did not re-peak."
Special thanks to Matt Sullivan from our WCDAS Team for providing a detailed
response!
-
Stonie Cooper, PhD
Software Engineer III
NSF Unidata
cooper@xxxxxxxx<mailto:cooper@xxxxxxxx>
