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GOES 17 Testing and Transition to Operations

GOES-17 Post-Launch Testing and Transition to Operations

August 17, 2018

The GOES-R Program is currently addressing a performance issue with the cooling system encountered during commissioning of the GOES-17 Advanced Baseline Imager (ABI) instrument. Currently the loop heat pipe (LHP) subsystem, which transfers heat from the ABI electronics to the radiator, is not operating at its designed capacity. This is preventing adequate cooling for some of the infrared (IR) channels on the instrument during parts of the night, leading to partial loss of ABI imagery.

Experts from NOAA, NASA, the ABI contractor, and industry are investigating the issue and pursuing several possible corrective actions. They are also working to identify the root cause of the issue.

Infrared signals with long wavelengths can be swamped by infrared light emitted by warm parts of the imager, degrading the signal. Cooling the detectors reduces this thermal “noise” in observations. During nighttime hours, the sun heats up the ABI detectors faster than they can be cooled. The detectors become warmer than they’re designed to operate, and they begin to radiate at temperatures closer to the wavelengths they’re attempting to detect from the Earth. Eventually, local emissions and dark current noise overwhelm the signal from the Earth, and the channels saturate, meaning a useful signal is not available. Channel availability will also fluctuate seasonally depending on the amount of solar radiation absorbed by the instrument.

GOES-17 is currently observing with more channels, at a higher resolution, and with more rapid refresh than what is available from the current GOES West satellite. While the GOES-17 imager will not produce the full set of planned data, it will provide more and better data than currently available. At the current estimates of ABI channel availability, the GOES-17 ABI will deliver more than 90% of the data it was intended to provide. NOAA is confident the GOES constellation will continue to meet the operational needs of the National Weather Service and forecasters across the nation.

NOAA plans to move GOES-17 into operational service in late 2018. The operational configuration will be determined in consultation with the NOAA Office of Satellite and Product Operations, the National Weather Service, and other stakeholders. Preparations are underway to operate GOES-17 in tandem with GOES-15 for an extended period of time to enable user evaluation.

Latest Status

August 28, 2018

GOES-17 Advanced Baseline Imager (ABI) data was declared “Beta” mature on August 27, 2018, following its Peer Stakeholder - Product Validation Review. The ABI data was released through GOES Rebroadcast (GRB) on August 28, 2018. Please see the Data Flow to Users section of this webpage for additional information.

Previous Status Updates

Show/Hide (below) all status updates on the GOES-17 ABI cooling system issue.

Estimated Channel Availability

Below is the current assessment of channel availability, as of September 13, 2018.

NOTE: This is a preliminary estimate that is subject to change as experts refine channel availability.

NOTE: Tables scroll horizontally on smaller windows and devices.

COLOR KEY: Available 24hrs/day Availability Exceptions
Band Channel Function Estimated Unsaturated Signal Cold Season (Solstice) Estimated Unsaturated Signal Warm Season (Pre-Eclipse)
1 0.47 mm Blue 24 hr 24 hr
2 0.64 mm Red 24 hr 24 hr
3 0.86 mm Veggie 24 hr 24 hr
4 1.38 mm Cirrus 24 hr 24 hr
5 1.61 mm Snow/Ice 24 hr 24 hr
6 2.25 mm Cloud Particle Size 24 hr 24 hr
7 3.90 mm Shortwave Window 24 hr 24 hr
8 6.18 mm Upper-Level Water Vapor 24 hr 18 - 20 hr
9 6.95 mm Mid-Level Water Vapor 24 hr 18 - 20 hr
10 7.34 mm Lower-Level Water Vapor 24 hr 18 - 20 hr
11 8.50 mm Cloud-Top Phase 24 hr 21 hr
12 9.61 mm Ozone 24 hr 18 - 20 hr
13 10.35 mm Clean IR Longwave Window 24 hr 24 hr
14 11.20 mm IR Longwave Window 24 hr 24 hr
15 12.30 mm Dirty Longwave Window 24 hr 21 hr
16 13.30 mm CO2 Longwave Infrared 24 hr 18 - 20 hr

Impact to Data Products

Many of the ABI Level 2 data products are affected to some degree, such as weather products showing cloud height and temperature, volcanic ash, derived motion winds, etc. since many of them use the longwave IR channels. A summary of data products and ABI band input follows. The Science Options Team is evaluating derived products based on channel availability and data quality in order to maximize mission effectiveness.

NOTE: Tables scroll horizontally on smaller windows and devices.

Wavelength (Micrometers) 0.47 0.64 0.865 1.378 1.61 2.25 3.9 6.185 6.95 7.34 8.5 9.61 10.35 11.2 12.3 13.3
Channel ID 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Baseline Products Lev 1 Reqmts Doc Priority
Cloud & Moisture Imagery 1 (KPP) X X X X X X X X X X X X X X X X
Aerosol Detection 1 X X X X X X X X X
Aerosol Optical Depth 1 X X X X X X
Clear Sky Masks 1 X X X X X X X X X X
Cloud Optical Depth 1 X X X X X
Cloud Particle Size Dist. 1 X X X X X
Cloud Top Phase 1 X X X X
Cloud Top Height 1 X X X
Cloud Top Pressure 1 X X X
Cloud Top Temperature 1 X X X
Legacy Vertical Moisture Profile 1 X X X X X X X X X
Legacy Vertical Temp Profile 1 X X X X X X X X X
Total Precipitable Water 1 X X X X X X X X X
Derived Motion Winds 1 X X X X X X
Radiances 1 X X X X X X X X X X X X X X X X
Hurricane Intensity 2 X
Rainfall Rate/QPE 2 X X X X X
Derived Stability Indices 2 X X X X X X X X X
Downward Solar Insolation Surf 2 X X X X X
Reflected Solar Insolation TOA 2 X X X X X
Fire Hot Spot Characterization 2 X X X X
Land Surface Temperature 2 X X
Snow Cover 2 X X X X X X X
Sea Surface Temperature 2 X X X X X
Volcanic Ash: Detection/Height 2 X X X X X
Wavelength (Micrometers) 0.47 0.64 0.865 1.378 1.61 2.25 3.9 6.185 6.95 7.34 8.5 9.61 10.35 11.2 12.3 13.3
Channel ID 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Baseline Products Lev 1 Reqmts Doc Priority
Fog & Low Stratus 3 X X X X X X X X
Aerosol Particle Size 3 X X X X X
Cloud Cover Layer Heights 3 X X X
Sea and Lake Ice (concentration, age/thickness, motion) 4 X X X X X
ASOS Cloud Product GOES-NOP continuity X X X
Wavelength (Micrometers) 0.47 0.64 0.865 1.378 1.61 2.25 3.9 6.185 6.95 7.34 8.5 9.61 10.35 11.2 12.3 13.3
Channel ID 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Baseline Products Lev 1 Reqmts Doc Priority
Day Cloud Phase Distinction AWIPS X X X
Nighttime Microphysics AWIPS X X X
Day Land Cloud AWIPS X X X
Day Convection AWIPS X X X X X X
Day Cloud Convection AWIPS X X
Day Ocean Cloud Convection AWIPS X X
Fire Temperature AWIPS X X X
Day Land Cloud Fires AWIPS X X X
Simple Water Vapor AWIPS X X X
Differential Water Vapor AWIPS X X
Air Mass AWIPS X X X X
Ash AWIPS X X X X
Dust AWIPS X X X X
Day Snow-Fog AWIPS X X X X
CIMSS Natural Color AWIPS X X X
SO2 AWIPS X X X X
Daytime Composite #1 AWIPS X X X
Daytime Composite #5 AWIPS X X

Path Forward

The anomaly investigation teams plan to provide findings and recommendations in fall of 2018. These include recommendations for the following: modifications to the GOES-T and GOES-U ABIs to address the loop heat pipe issue, operation of GOES-17 to maximize mission performance, and best constellation options for incorporating GOES-17, including potential changes to the operational usage of other assets.

NOAA plans to move GOES-17 into operational service in late fall of 2018. Preparations are underway to operate GOES-17 in tandem with GOES-15 for an extended period of time to enable user evaluation.

Data Flow to Users

The GOES-17 ABI Level 1b (L1b) and Cloud and Moisture Imagery (CMI) data was declared “Beta” validated on August 27, 2018, following the Beta Maturity Peer Stakeholder – Product Validation Review. The data was released through GOES Rebroadcast (GRB) on August 28, 2018.

NOAA's GOES-17 satellite has not been declared operational and its data are preliminary and undergoing testing. Users receiving these data through any dissemination means (including, but not limited to, PDA and GRB) assume all risk related to their use of GOES-17 data and NOAA disclaims any and all warranties, whether express or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose.

The ABI L1b and CMI data products are calibrated and geo-located radiances of the 16 ABI bands over the Full Disk (FD) of the Earth, the Continental United States (CONUS) region, the Mesoscale (MESO) regions, and certain instrument calibration and engineer data. Beta maturity is defined by the following:

  • Initial calibration applied (L1b);
  • Rapid changes in product input tables / algorithms can be expected;
  • Product quick looks and initial comparisons with ground truth data not adequate to determine product quality;
  • Anomalies may be found in the product and the resolution strategy may not exist;
  • Product is made available to users to gain familiarity with data formats and parameters (via GRB);
  • Product has been minimally validated and may still contain significant errors; and
  • Product is not optimized for operational use.

Beta users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized. Persons desiring to use the GOES-17 ABI Beta maturity L1b products for any reason, including but not limited to scientific and technical investigations, are encouraged to consult the NOAA ABI calibration scientists for feasibility of the planned applications.

Known issues being investigated include the following:

  1. An anomaly with the ABI Loop Heat Pipe (LHP) prevents the instrument cooling system from maintaining sufficiently cool temperatures during certain parts of the day and year. Data quality will fluctuate seasonally depending on the amount of solar radiation absorbed by the instrument. During the instrument’s “cool” seasons (near the summer and winter solstice), all channels are expected to be nominal 24 hours per day. During the instrument’s “warm” seasons (before and after the vernal and autumnal equinox), experts estimate 7 channels (Bands 1-7) will be of nominal quality 24 hours per day and the other 9 channels (Bands 8-16) will be degraded and images will be of reduced quality or unusable 2-6 hours per night. These estimates are preliminary and are still being refined. The warmest part of the season is coming up in early September and performance estimates will need to be confirmed through observation during that time.
  2. Significant stray light exists for VNIR channels approximately one hour before and after satellite local midnight for approximately forty days during the eclipse season before the vernal (spring) equinox and after the autumnal (fall) equinox, and may exist in other days of the year.
  3. Stray light exists for Band 7 approximately one hour before and after satellite local midnight for approximately forty days during the eclipse season before the vernal (spring) equinox and after the autumnal (fall) equinox. The intensity of the stray light is less than the requirements, but may affect certain applications.
  4. Band 1 radiances may be brighter on the west end than on the east end by 1% or more.
  5. Band 4 radiances are about 7% darker, and Band 5 radiances are about 7% brighter than commonly accepted values from comparable satellites products. These may be due to error in the gains of these channels so the bias is larger for brighter scenes.
  6. Band 2 is brighter than commonly accepted values by up to 10%.
  7. There are periodic infrared calibration anomalies (PICA) present in the data that can be seen as regular and repeating pulses in infrared brightness temperatures. The infrared calibration may produce an error with a periodicity depending on timeline.
  8. There are periodic infrared calibration anomalies (PICA) present in the data that can be seen as regular and repeating pulses in infrared brightness temperatures. The infrared calibration may produce an error with a periodicity depending on timeline.
  9. Image striping may occur across all 16 channels.

Contacts for specific information on the ABI data:

Fred Wu (L1b) xiangqian.wu@noaa.gov
Tim Schmit (CMI) tim.j.schmit@noaa.gov

There will be occasional interruptions to the flow while various post-launch tests occur and those interruptions will be communicated through the GRB forum distribution list.

A notification will be sent when the data is considered Provisionally Mature and suitable for operational use after further testing and validation.

Contact information for further information: NOAA Office of Satellite and Product Operations (OSPO) User Services at SPSD.UserServices@noaa.gov

See the OSPO General Satellite Messages webpage for this and other satellite related messages.

DATA QUALITY FLAGS

The GOES-17 ABI Level 1b (L1b) and Cloud and Moisture Imagery (CMI) Peer Stakeholder-Product Validation Review is scheduled for August 27, 2018. If the L1b products achieve Beta maturity level at that review then GOES-17 ABI L1b products will be added to the GOES Rebroadcast (GRB) radiofrequency stream as soon as August 28. All of the GOES-17 ABI L1b products including channels degraded by the ABI cooling system anomaly will be distributed via GRB. Since ABI channels 8-16 could be degraded during parts of the day, the pixels that are impacted will be flagged during the data quality control (QC) check. The Data Quality Flags (DQF) are added to the metadata during product generation processing in the ground system and included in the L1b radiance product transmitted on GRB. There are no near-term changes in the ground system planned for the data quality flags so the GOES-R Product Definition and Users’ Guide (PUG) Volume 4 is the reference. The DQF values are as follows:

DQF value 0 represents a pixel that passed the QC check and is labeled: good_pixel_qf

DQF value 1 represents a pixel that conditionally passed the QC check because it has some usable data and it is labeled: conditionally_usable_pixel_qf

DQF value 2 represents a pixel that failed the QC check because the pixels values are out of range and it is labeled: out_of_range_pixel_qf

DQF value 3 represents a pixel that had no values probably because the data was missing and it is labeled: no_value_pixel_qf

Early checks indicate users will see DQF=2 when the affected infrared (IR) channels are saturated.

The metadata in the ABI Level 1b radiances product provides statistical and other properties of the product image and supports diagnosis of algorithm anomalies. Specific metadata includes:

  • Number of good and conditionally usable, and missing pixels.
  • Number of saturated and undersaturated pixels.

The percentages of pixels assigned to each DQF value are also included in the product.

Data Sharing Guidance

Below is the guidance for sharing GOES-17 images, plots, data files, and publications.

IMAGE & PLOT FILES

Once the official NOAA/NASA release for an instrument has been distributed, you may share instrument images/plots (not data files) from GOES-17, however acquired or processed. These posts must contain the caveat: “GOES-17 Preliminary, Non-Operational Data.” Data files may not be distributed until after the data has reached “Provisional” maturity.

DATA FILES

Once an instrument’s data has reached Provisional maturity, you may share data files. All data or image postings should STILL state: “GOES-17 Preliminary, Non-Operational Data”. Data are only considered operational once Provisional maturity is attained AND GOES-17 is in the operational GOES-West assignment. These dates are subject to change in conjunction with testing and validation schedule changes.

PUBLICATIONS

If you are submitting a paper to be published, you may include pre-Provisional instrument data/images/plots as long as it will not be published until after Provisional validation is declared for that instrument. Exercise caution in publishing data regarding anomalies or artifacts as there are ongoing updates to the product quality.

"Sharing" includes methods such as posts on social media, showing or sending to friends/family, retaining on insecure drives, speaking to the press or media (whether direct or indirect), posting on blogs, posting electronic versions of presented presentations or papers, etc. This list is not exhaustive-- if you have a specific concern, see contact info below.

These restrictions apply only to instrument data/images/plots and do not apply to spacecraft or ground system engineering data.

IMPORTANT:

Recommended language from the NOAA Office of General Counsel to be used for emails, slides, and webpages:

NOAA's GOES-17 satellite has not been declared operational and its data are preliminary and undergoing testing. Users receiving these data through any dissemination means (including, but not limited to, PDA and GRB) assume all risk related to their use of GOES-17 data and NOAA disclaims any and all warranties, whether express or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose.

If you have any questions about this policy, reach out to kathryn.mozer@noaa.gov, elizabeth.kline@noaa.gov, or kevin.fryar@noaa.gov.

Frequently Asked Questions

Show/Hide All Answers

What exactly is going wrong with the cooling system?

The ABI cooling system is necessary to keep the instrument’s components at proper operating temperatures. The ABI infrared detectors need to be very cold so that they can accurately measure the thermal energy being radiated from the Earth’s atmosphere. The detectors need to be cooled to varying degrees (some as low as -351℉) based on where they fall on the electromagnetic spectrum to function properly.

The ABI utilizes several assemblies and subsystems to maintain thermal control of the instrument. There is a mechanical cooler that pumps heat away from the visible and infrared detectors to cool them to their required temperatures. The heat from this cryocooler and the instrument electronics are transported to an external radiator by the loop heat pipes. The radiator is a large reflective surface that is designed to reject excess thermal energy to space. Other components of the thermal system are blankets and shields that that protect the instrument from absorbing too much solar radiation.

The loop heat pipes are not properly transferring excess thermal energy to the radiator, resulting in overheating of the cryocooler and other electronics. When this happens, these components need to be turned off to prevent them from being damaged.

What are the specific root causes being investigated?

The root cause investigation team has narrowed the possibilities to a few likely causes. There may be excess non-condensable gas inside the loop heat pipes (LHPs) or foreign object debris. Either one of those might prevent the fluid from traveling through the LHP as intended. Another possibility is mechanical damage to the LHPs. The ground testing that we have planned is intended to try to narrow down the causes.

Will this issue impact GOES-17 going into operational service?

Despite the cooling system issue, we still plan to move GOES-17 into operational service in late 2018. Preparations are underway to operate GOES-17 in tandem with GOES-15 for an extended period of time to enable user evaluation.

How is GOES-17’s performance compared to the current GOES West satellite, GOES-15?

Even during its checkout phase, GOES-17 is observing with more channels, at higher resolution, and with more rapid refresh than GOES-15. GOES-17 also includes the Geostationary Lightning Mapper, and four instruments for improved solar and space weather monitoring and forecasting. While the GOES-17 imager will not produce the full set of planned data, we will receive more and better data than we currently have. We are confident we will be able to meet the operational needs of the National Weather Service.

Is there an issue with the GOES-16 ABI or Himawari imager loop heat pipes?

Since first learning of the cooling system issue with GOES-17, the Independent Review Team has reviewed GOES East (GOES-16) data and the analysis shows there is evidence of some reduced functionality from these loop heat pipes as well. The investigation team is assessing how this may be related to the GOES-17 issue. Despite the noted change, the current GOES-16 LHP performance is sufficient for full ABI operation and the overall orbital trend does not indicate progressive degradation. At this time, NOAA does not anticipate any impact to the GOES-16 operational satellite.

Review of the Himawari-8 and -9 data does not generally show the phenomena that are observed in the GOES-16 and GOES-17 ABI data.

What does this mean for the GOES-T and GOES-U ABIs and launch schedule?

Pending results of the anomaly investigation corrective actions may be required on the GOES-T and GOES-U satellites. We are exploring design modifications for the GOES-T and U ABIs to ensure we do not experience the cooling issue moving forward.

It is too soon to know how this anomaly will affect GOES-T and GOES-U launch schedules, but we will not launch these satellites until we fully understand and have resolved the issue.

How will this issue impact the National Weather Service’s ability to forecast weather conditions?

There are no immediate impacts to forecasting as the satellite is still in testing phase. NOAA’s operational geostationary constellation is healthy and monitoring weather across the nation each day, so there is no immediate effect from this performance issue. The constellation includes GOES-16, operating as GOES-East, GOES-15, operating as GOES-West and GOES-14, operating as the on-orbit spare. Additionally, during checkout, GOES-17 is providing more and better data than we currently have from GOES-15. We are confident we will continue to meet the operational needs of the National Weather Service.

What is the expected resolution timeline?

Timelines will be assessed as the investigation continues, but we expect the effort to continue for several months as we consider the failure analysis and the overall observing system response to deliver on overall mission objectives. At this point, we have tests planned for August and September 2018.

Additional Information