ocean surface topography science team meeting
DESCRIPTION
Ocean Surface Topography Science Team Meeting. Jason-1 JPL Project Status Glenn M. Shirtliffe NASA/JPL Jason-1 Project Manager. Jason-1 Mission Overview. - PowerPoint PPT PresentationTRANSCRIPT
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 1March 12, 2007
Ocean Surface TopographyScience Team Meeting
Jason-1 JPL Project
Status
Glenn M. Shirtliffe
NASA/JPL Jason-1 Project Manager
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 2March 12, 2007
Jason-1 Mission Overview
The 14+ year combined data record from T/P and Jason-1 is the only climate data record that is able to address the problem of global change of sea level and ocean circulation and its relation to climate change.
Continuation of this data record is critical to meeting NASA’s Earth Science goals.
A key objective of extending Jason is to have overlap with OSTM and perform cross-calibration to ensure consistency in the data record initiated by TOPEX/Poseidon in 1992.
The consistent data record built by T/P, Jason-1 and OSTM will then become the first multi-decadal global record for addressing the issue of sea level rise, which has been identified by the 2007 IPCC assessment as one of the most important consequences and indicators of global climate change.
The OSTM Mission will extend the global sea level data record into the decade of 2010s.
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 3March 12, 2007
Jason-1 JPL Mission Operations: Current Status
Joint CNES-JPL operations continuing to proceed extremely well Weekly joint telecon for normal satellite uploads, and as required Regular proficiency and training tests ongoing
Instruments and ground operations systems at JPL are meeting, and routinely exceeding all mission objectives
Jason entered extended operations phase in December 2006 The Jason Mission is currently funded by NASA through October 2009 A second NASA “Senior Review” is currently in progress
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 4March 12, 2007
Jason-1 Ground Status
Earth terminal operations are nominal and meeting mission requirements.
S/C Telemetry, command and health/safety monitoring is nominal. Staff is fully trained for routine operations and contingency procedures.
Sequencing Hardware/software and team are operating well All products and services are meeting requirements
Earth terminal scheduling Generation of routine flight time-tagged sequence Generation of all routine flight operations support data products
Many tasks at JPL control center are performed automatically
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 5March 12, 2007
JPL Mission Operations Assessment
In the period since the last OSTST Meeting in Venice, no science or engineering data has been lost due to NASA ground system anomalies or command errors.
The current NASA ground system configuration and station performance is adequate to meet mission requirements.
In the past year, 95.3% of all possible over-ocean science data was received.
Excluding the two-week safe hold event in Oct.-Nov. 2006, the total data recovery rate exceeds 99.97% of all available science data.
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 6March 12, 2007
JPL Mission Operations Concerns
TOPEX/Poseidon—Jason-1 collision avoidance monitoring TOPEX/Poseidon can no longer be maneuvered. Jason-1 and OSTM must monitor the drift of TOPEX/Poseidon
and possibly maneuver to avoid a collision.
Occasional AUS ET pass loss issues remain open: DCN saturation on the primary 256-kbps line often results in the
loss of AUS telemetry and command connections. Recovery requires a base-band hardware (SEBB) reboot after the
lost pass. JPL and CNES are investigating router prioritization of JTCCS-
JCCC traffic.
The 128-kbps backup DCN line will be discontinued by NASA Jason must identify and pay for a replacement solution (ISDN)
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 7March 12, 2007
Jason-1 JPL Mission Operations Summary
Mission operations will continue through (at least) launch of OSTM to satisfy the goal of long-term contiguous ocean surface topography data
Data reprocessing will continue to be a high priority in the near-term
A comprehensive 102-Cycle reprocessing effort is nearing completion (Began in Dec. 2006; nearing completion in Mar. 2007) Tentative plans call for one additional comprehensive reprocessing
campaign
OSTST should continue its on-going advocacy of the necessity and requirements for future missions to support and maintain robust research programs on ocean circulation, climate variability, and sea-level monitoring
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 8March 12, 2007
Jason-1 JPL Instrument Status
NASA/JPL provided three payload instruments for the Jason-1 Mission:
Microwave Radiometer (JMR)
Laser Retroreflector Array (LRA)
Turbo Rogue Space Receiver (TRSR)
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 9March 12, 2007
Jason-1 Microwave Radiometer (JMR)
Presentation contributors: Shannon Brown, JPL Shailen Desai, JPL
Summary: Continues to operate nominally No Alarms No Commanding (Except for SHM recoveries) No engineering anomalies since launch Three confirmed science anomalies since launch:
Cycle 31 and 68 anomalies corrected in Version B GDRs Cycle 136 anomaly will be corrected in Version C GDRs
One possible science anomaly after Cycle 177 safehold is under investigation Will be corrected in Version C GDRs, if necessary
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 10March 12, 2007
JMR Measurements on Version B GDRs
Recalibration of the JMR performed to correct anomalies in Version A GDRs.
Cycle 31 and 68 anomalies corrected. Cycle 136 anomaly < 2 mm in wet path delay. Cycle 177 anomaly likely to be < 2 mm in wet path delay.
Small yaw state dependence possibly introduced - under investigation. Calibration of JMR continues in preparation for Version C GDRs.
-15
-12
-9
-6
-3
0
3
6
9
12
15
0 20 40 60 80 100 120 140 160 180 200
JMR (GDRB) - GPSJMR (GDRB) - SSMIJMR (GDRB) - TMIJMR (GDRB) - ECMWF
Cyc
le A
vera
ge
of
Wet
Pat
h
Del
ay D
iffe
ren
ces
(mm
)
Jason Repeat Cycle
JMR from GDRB
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 11March 12, 2007
Laser Retroreflector Array (LRA)
Presentation contributor: Glenn Shirtliffe, JPL
Summary: The LRA continues to provide
returns adequate for tracking.
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 12March 12, 2007
Presentation contributors: Tim Munson, Cognizant Engineer, JPL Glenn Shirtliffe, JPL
Science contributors: Bruce Haines, JPL Shailen Desai, JPL Willy Bertiger, JPL
Summary:
TRSR2 (primary receiver) operates in a degraded mode, but still supports orbit determination (with significantly reduced accuracies).
TRSR1 (redundant receiver) was powered up to support a software upload but experienced a critical failure and will remain powered off.
Turbo Rogue Space Receiver (TRSR)
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 13March 12, 2007
TRSR1 Redundant Receiver Status
TRSR1 failed prior to a software upload on 13 September 2006.
TRSR2 was powered down and the redundant TRSR1 was powered up to perform a software code upload.
Real-time monitoring indicated that the turn on was normal in all respects.
While Jason was out of ground station contact, the primary current degraded and after approximately one hour the receiver went offline.
Recorded housekeeping data showed that the 1553 current and voltage monitors showed sudden erroneous operations during the preceding hour.
Due to the severity of the problem and the interface to the spacecraft, the TRSR Instrument Team does not anticipate powering up the TRSR1 for any further testing or diagnostics.
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 14March 12, 2007
TRSR2 Performance Degradation
TRSR2 reset behavior changed during a fixed-yaw period in mid-July 2006.
TRSR2 nominally resets 4-9 times a day from different sources, but is now becoming increasingly less tolerant of these resets.
The preponderance of these resets occur in the South Atlantic Anomaly and at high orbital latitudes indicating a radiation component.
The TRSR receivers have a significant number of commercial parts susceptible to radiation.
There is a clear correlation between these problems and the temperature of the TRSR unit, indicating a total-dose radiation effect.
The problem became progressively worse to the point that it not only occurred during fixed-yaw periods, but now occurs during the cooler yaw-steering modes. This is also indicative of a total-dose radiation effect.
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 15March 12, 2007
TRSR Long-Term Performance Metrics
4
6
8
DAILY POSTFIT RESIDUAL OF IONOSPHERE-FREE CARRIER PHASE (LC)
RM
S (
mm
)
0
1000
2000
DAILY NUMBER OF TRACKING OBSERVATIONS (LC, FROM POD)
No.
0
50
100 PERCENTAGE TIME (DAILY) WITH NO TRACKING DATA
2002 2003 2004 2005 2006 2007
RM
S (
mm
)
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 16March 12, 2007
1-cm Orbit Accuracy Achieved and Maintained
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 17March 12, 2007
TRSR POD Performance Summary
Life expectancy of the TRSR receivers has been surpassed
TRSR2 Continues to provide tracking data of high accuracy. 4-5 mm for carrier phase (biased range) 20 cm for 5-min compressed pseudorange (vs. 50–70 cm for GPSDR on T/P)
Temporal coverage and geometric diversity of tracking data has been severely compromised since mid-2006
Nominal (2002–2006): 8–12 GPS tracked spacecraft simultaneously Current: 4 satellites tracked with 12-hr on/off cycle
2002–2006 data set new POD standards for both accuracy and latency <1-cm RMS radial accuracy for definitive solutions
0.8 cm RMS agreement with new GDR-B orbits (SLR+DORIS+GPS) 1.1 cm RMS agreement with independent high-elevation SLR data.
2-cm RMS radial accuracy within 5–7 hrs of real time Capitalizes on NASA global differential GPS system Real-time orbit solutions are a cornerstone of JPL’s near-real-time sea
surface height product
POD performance in current, degraded tracking mode is highly variable Typical RMS radial accuracies of 1–5+ cm.
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 18March 12, 2007
T/P and Jason-1 science open literature database available on-line
Over 2,000 articles citing data utilization from TOPEX/Poseidon and Jason-1 have appeared in over 335 Journals or Publications
Searchable by author, title, keyword, abstract, & category for T/P and Jason-related science, engineering, applications, and education research from 1990-present
TOPEX/Poseidon and Jason-1 Science/Outreach Success
OSTST MeetingOSTST MeetingHobart, Australia
GMS - 19March 12, 2007
TOPEX/Poseidon, Jason-1 and OSTMOnward and Upward!
T/P data reprocessing effort ongoing, funded primarily through science team and PO.DAAC OSTST input will be critical to ensure that a continuous validated data record is available
Scientists, NASA and CNES must continue joint efforts to demonstrate the applications and value of ocean science to the public Societal benefits will define NASA/CNES strategy for long-term ocean observing systems
Tandem Science Mission
OSTM