38^th^ ARGOS O/C WP, NOAA

Agenda Items: D1 Prepared by: M.Fitzmaurice

> June 30-July 2, 2004

Review of Spacecraft Current On-orbit Performance

NOAA-17, 16, 15, 14, 12, and 11

**[EXECUTIVE SUMMARY]{.underline}**

The current on-orbit operational satellite constellation maintained by
NOAA consists of the NOAA-17, 16, 15, 14, 12, and 11 satellites. NOAA-17
was launched June 24, 2002 and deemed the operational \'morning\'
(daylight equator crossing is around 1030 local) satellite in October
2002 replacing NOAA-15. With the AMSU A1 instrument failing on NOAA-17
in October 2003, NOAA-15 has been re-tasked to provide the operational
sounding data using its AMSU A1 instrument. This event is significant to
the Argos community in that the data from NOAA-15 is recovered in its
entirety with an operational priority equivalent to NOAA-17 and NOAA-16.
When NOAA-16 was launched on September 21, 2000 it eventually replaced
NOAA-14 as the primary afternoon satellite (daylight equator crossing is
around 1330 local). NOAA-16 has had various on-orbit anomalies that
prevent the satellite from operating at its full capability in providing
data for user community. These anomalies have necessitated the call-up
of NOAA-N in Febraury 2005. The NOAA-14 satellite\'s orbit has drifted
to an almost 7:00 pm (local) equator crossing node (ECN). It is
considered a backup satellite both operationally and in science data
recovery. With \'backup\' status, any conflicts with NOAA-17, NOAA-16,
or NOAA-15 data recovery efforts will be mitigated with NOAA-14
receiving a lower priority (i.e., less timely data retrieval). NOAA-12
is currently in standby mode and transmitting APT and HRPT data
real-time, and \'dumping\' STIP (2-4 orbits of recorded low rate data
which includes Argos DCS) once per day. The NOAA-11 is a standby
satellite currently planned for de-activation in mid-June 2004.

**[ACTION REQUIRED]{.underline}**

No specific action is required.

Agenda Item: D1

Review of Spacecraft Current On-orbit Performance

NOAA-17, 16, 15, 14, 12, and 11

**[NOAA-17]{.underline}**

The NOAA‑17 satellite was successfully launched at 11:22am PDT/2:22pm
EDT from Vandenberg Air Force Base on Monday June 24, 2002. The orbital
altitude is approximately 860 km. NOAA-17 began fully operating as the
primary morning polar satellite on March 20, 2003. It replaced NOAA-15
as the primary operational afternoon ascending satellite. Due to an
on-orbit anomaly with the AMSU A1 instrument, the NOAA-15 satellite is
being used to provide the missing morning orbit operational sounding
data. The current equator crossing time for NOAA-17 is 2213 local
ascending node (mid-morning descending). The Satellite Operations and
Control Center (SOCC) in Suitland, Maryland currently retrieves all (24
hour) Data Collection System (DCS) instrument data via Global Area
Coverage (GAC) playbacks during 10-12 real-time passes over their
Fairbanks, Alaska and Wallops Island, Virginia Command and Data
Acquisition (CDA) Stations each day.

**Note: The DCS instrument and all of its Data Recovery Units are fully
operational with no anomalies reported. All DCS data is recovered at the
highest operational priority as NOAA-17 is deemed a primary satellite.**

**[NOAA-16]{.underline}**

The NOAA‑16 satellite was successfully launched at 3:22am PDT/6:22am EDT
from Vandenberg Air Force Base on Thursday September 21, 2000 into an
orbital altitude of approximately 860 km. NOAA-16 began operating as the
primary afternoon polar satellite on March 20, 2001, replacing NOAA-14.
The current equator crossing time for NOAA-16 is 1401 local ascending
node. The SOCC is currently retrieving all (24 hour) DCS instrument data
via 10-12 real-time GAC playback opportunities each day. As the primary
afternoon satellite, when conflicts with other satellite data retrieval
opportunities exists, data retrieval priority is higher and equivalent
to N17.

**Note: The DCS instrument and all of its Data Recovery Units are fully
operational and no anomalies reported.**

**[NOAA-15]{.underline}**

The NOAA-15 satellite was successfully launched on May 13, 1998 and
began operating as the primary morning polar satellite on December 14,
1998. With the launch of N17 in June 2002, N15 became a secondary
satellite in October 2002. The October 2003 failure of the AMSU A1
on-board NOAA-17 necessitated that the NOAA-15 AMSU A1 instrument
provide the \'morning\' sounding data. This event has had a positive
effect on the Argos DCS community in that the retrieval of NOAA-15 data
and its timely transfer to the user community is now an operational
priority equivalent to NOAA-17 and NOAA-16 (i.e., all DCS data is
retrieved via GAC retrievals). The current N15 equator crossing time is
0651 local.

**Note: The DCS instrument and all of its Data Recovery Units are fully
operational and no anomalies reported.**

**[NOAA-14]{.underline}**

NOAA-14 was successfully launched on December 30, 1994 into an 850 km
orbit. Since NOAA-16 became operational on March 20, 2001, NOAA-14 and
has been designated as standby afternoon satellite, but, due to orbit
drift, its equator crossing time is that of a morning satellite.

With this extensive drift to an early morning orbit, degradation to
environmental products exists. NOAA-14 has drifted from its 1330 Local
orbital insertion 6.5 years ago and continues to drift at an approximate
rate of five (+5) minutes per month. The current equator crossing time
for this satellite is 1851 local ascending node. Currently, the SOCC
retrieves all (24 hour) DCS data via stored TIP playbacks via 4
real-time satellite contacts per day.

**Note: The DCS instrument and all of its Data Recovery Units are fully
operational and no anomalies reported.**

**[NOAA-12]{.underline}**

NOAA-12 was launched on May 14, 1991 into an 825 km orbit. The current
equator crossing time for this satellite is 1644 local descending node
(launched into a 0732 descending orbit in 1991). NOAA-12 is currently
standby satellite. It currently uses a \'recursive\' stored command
table and is only contacted twice per day for the downlink of four
orbits of stored TIP (STIP). Due to conflicts with higher priority
satellites, the four orbits of STIP (which contain DCS data) are not a
routine coverage area (i.e., the time is dependent on when SOCC
\"squeezes\" a real-time contact and which recorder is ready for
playback).

**Note: The DCS system is fully operational.**

**[NOAA-11]{.underline}**

The NOAA-11 is (at the time of this paper\'s generation) planned to be
de-activated on June 16, 2004. The Argos community provided an
assessment for de-activating NOAA-11 and it is the author\'s
understanding that they concur with NOAA\'s plan.

**Note: The Data Collection System (DCS) is fully operational on its
single receiver. Data Recovery Unit 4 had a low throughput, has been
turned off, and is considered failed. The three remaining DRUs are
operating normally. Analog telemetry channel 95, DCS receiver gain,
showed a 6 dB drop in gain on March 19, 1992.**

Current status of all NOAA satellites can be obtained with monthly
updates at:

[http://www.oso.noaa.gov](http://www.oso.noaa.gov/)

**[Summary]{.underline}**

As can be readily ascertained, NOAA\'s current constellation of 5
satellites is providing extensive coverage. The retrieval of Argos DCS
data is being accomplished on all 5 satellites using either GAC or STIP
dataset recovery, with 24 hour coverage being provided by 3 satellites
in early(15), mid-morning(17), and afternoon(16) orbits. With the
planned launch of NOAA N in February 2005 and the deactivation of NOAA
11, NOAA\'s current operational satellites are fully meeting the needs
of the Argos user community.