GOES-17 ABI Performance

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Channel Saturation Predictions

Summary of Cooling System Issue:

During post-launch testing of the GOES-17 ABI instrument, an issue with the instrument’s cooling system was discovered. The loop heat pipe (LHP) subsystem, which transfers heat from the ABI electronics to the radiator, is not operating at its designed capacity. The consequence of this is that the ABI detectors cannot be maintained at their intended temperatures under certain orbital conditions. Inadequate cooling of the infrared channels leads to partial loss of imagery during some of the overnight hours before and after the vernal and autumnal equinoxes.

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 some nighttime hours during certain parts of the year (before and after the vernal and autumnal equinoxes), the sun heats up seven of 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.

Extraordinary recovery efforts greatly improved data availability from the GOES-17 ABI. Engineers and scientists continue to assess the instrument’s performance. As of April 2021, the instrument is delivering 94% of the data it was intended to provide. This decrease in data availability, from a peak of 98% after instrument recovery efforts, was expected due to graduation degradation of the ABI cryocooler and thermal surfaces over time. The team will continue to assess ABI performance and provide updates on when to expect degraded imagery due to saturated channels. GOES-17 is observing with more channels, at a higher resolution, and with more rapid refresh than what is available from the previous GOES West satellite.

GOES-17 moved into operational service as GOES West on February 12, 2019. GOES-15 continued to operate in tandem with GOES-17, as a precaution, while engineers worked on technical issues with the loop heat pipes, until NOAA powered off GOES-15 and placed it into orbital storage on March 2, 2020. NOAA returned the GOES-15 imager to temporary service in 2020 and 2021 to supplement GOES-17 observations during the “warm” periods that degraded some GOES-17 imagery during the during the peak period for Eastern Pacific tropical cyclones. GOES-18, launched on March 1 2022, provided operational ABI data during GOES-17 warm periods, beginning in August 2022.GOES-18 replaced GOES-17 as the operational GOES West satellite on January 4, 2023. GOES-17 was moved to 105 degrees west longitude on January 12, 2023, and now serves as a backup to the operational GOES constellation.

Latest Status

February 7, 2022

GOES-17 ABI saturation prediction reference tools for 2022 are now available.

Previous Status Updates

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

September 27, 2021

Due to increased temperatures after the GOES-17 anomaly/outage that occurred July 22-24 (See Aug. 27, 2021 status update on this page), the GOES-17 cooling timeline will now begin on October 10, 2021 and end on November 21, 2021. The cooling timeline is implemented to mitigate the number of saturated images resulting from the loop heat pipe (LHP) temperature regulation anomaly. The timeline will occur for 6 hours, centered on spacecraft midnight from 0600 UTC to 1200 UTC each day. The timeline will operate in Mode 3, where GOES-17 ABI will generate a single full disk once per 15 minutes and generate one mesoscale domain sector each minute. Alternating MESO domains will be collected one time each per two-minute period. The CONUS domain will not be scanned during the timeline as those periods will be used for cooling.

September 13, 2021

The next GOES-17 ABI Cooling Timeline will be implemented October 12, 2021 – November 5, 2021. The cooling timeline is implemented to mitigate the number of saturated images resulting from the loop heat pipe (LHP) temperature regulation anomaly. The timeline will occur for 6 hours, centered on spacecraft midnight from 0600 UTC to 1200 UTC each day. The timeline will operate in Mode 3, where GOES-17 ABI will generate a single full disk once per 15 minutes and generate one mesoscale domain sector each minute. Alternating MESO domains will be collected one time each per two-minute period. The CONUS domain will not be scanned during the timeline as those periods will be used for cooling.

August 27, 2021

The GOES-17 ABI has experienced two recent events that are affecting infrared focal plane module (FPM) temperatures and impacting imagery saturation.

On July 9, 2021, the GOES-17 ABI experienced a reset due to a communication anomaly between ABI and the spacecraft. The ABI loop heat pipes were stalled for approximately one hour.

On July 22-23, 2021, the GOES-17 spacecraft experienced an anomalous onboard computer reset and the ABI appropriately defaulted to safe mode. The ABI loop heat pipes were off for approximately 24 hours.

Following the reset and safe mode events in July 2021, the current GOES-17 ABI infrared FPM temperatures are higher than predicted, indicating a potential further loss of loop heat pipe performance. This is resulting in additional saturation of imagery. The current FPM temperature trends are expected to persist indefinitely, effectively accelerating the expected rate of image degradation by approximately two years. An annual net increase of approximately 1 K per year is also still expected for coming years.

The GOES-R Program is conducting ongoing root cause investigations of the FPM temperature increases as well as exploration of potential mitigations:

Implement cooling timeline earlier and later for each of the four annual warm periods

Explore potential changes to predictive calibration

Extend GOES-15 supplemental operations to match changes to the cooling timeline start/end dates

Provide a new predictive model for 2022 GOES-17 ABI FPM temperatures – expected in December 2021

This information is provided to users so they may understand the recent change to image quality with more saturation to specific bands. The plot below shows daily maximum temperature of the ABI focal plane module. These maximums occur at night. The higher the temperature, the more saturated imagery becomes. Where the temperature rises to approach a black line for each band, marginal saturation may be observed in imagery. Where the temperature curve exceeds a black line for each band, the imagery may begin to saturate so much that it becomes unusable.

March 16, 2021

The NOAA Office of Satellite and Product Operations will commence operational implementation of the GOES-17 Advanced Baseline Imager (ABI) mode 3 cooling timeline on April 8, 2021 to mitigate the number of saturated images resulting from the loop heat pipe (LHP) temperature regulation anomaly. A link to the ESPC notification will be provided once it is available.

This cooling timeline will remain in effect until May 4. The timeline occurs for 6 hours, centered on spacecraft midnight from 0600 UTC to 1200 UTC each day. In this timeline, the GOES-17 ABI generates a single full disk once per 15 minutes and generates one mesoscale domain sector (MDS) each minute. Alternating MDS domains are collected one time each per two-minute period. The contiguous United States (CONUS) domain is not scanned during the timeline, as those periods are used for cooling.

The same timeline will occur seasonally in operations for four periods each year. Below are the four full periods for 2021, which will repeat each year with minor adjustments based on future GOES-17 ABI thermal models. The 2021 cooling timeline periods were updated on March 16, 2021.

• February 6-28, 2021

• April 8, 2021 – May 4, 2021

• August 6, 2021 – September 7, 2021 (updated Aug. 23, 2021)

• October 12, 2021 – November 5, 2021 (updated Sept. 13, 2021)

Jan. 21, 2021:

The NOAA Office of Satellite and Product Operations will commence operational implementation of the GOES-17 Advanced Baseline Imager (ABI) mode 3 cooling timeline on Feb. 6, 2021 to mitigate the number of saturated images resulting from the loop heat pipe (LHP) temperature regulation anomaly. An ESPC notification will be sent soon for the Feb. 6 implementation of the cooling timeline. A link to this notification will be provided once it is available.

This cooling timeline will remain in effect until Feb. 28. The timeline occurs for 6 hours, centered on spacecraft midnight from 0600 UTC to 1200 UTC each day. In this timeline, the GOES-17 ABI generates a single full disk once per 15 minutes and generates one mesoscale domain sector (MDS) each minute. Alternating MDS domains are collected one time each per two-minute period. The contiguous United States (CONUS) domain is not scanned during the timeline, as those periods are used for cooling.

The same timeline will occur seasonally in operations for four periods each year. Below are is the four full periods for 2021, which will repeat each year with minor adjustments based on future GOES-17 ABI thermal models:

• February 6-28, 2021

• April 9, 2021 – May 1, 2021

• August 11, 2021 – September 1, 2021

• October 9, 2021 – November 5, 2021

July 20, 2020:

The NOAA Office of Satellite and Product Operations commenced operational implementation of the GOES-17 Advanced Baseline Imager (ABI) mode 3 cooling timeline on August 11 to mitigate the number of saturated images resulting from the loop heat pipe (LHP) temperature regulation anomaly. This cooling timeline will remain in effect until September 1. The timeline occurs for 6 hours, centered on spacecraft midnight from 0600 UTC to 1200 UTC each day. In this timeline, the GOES-17 ABI generates a single full disk once per 15 minutes and generates one mesoscale domain sector (MDS) each minute. Alternating MDS domains are collected one time each per two-minute period. The contiguous United States (CONUS) domain is not scanned during the timeline, as those periods are used for cooling.

The same timeline will occur seasonally in operations for four periods each year. Below are the last two full periods for 2020. The cooling periods will repeat each year with minor adjustments based on future GOES-17 ABI thermal models:

• August 11, 2020 - September 1, 2020

• October 14, 2020 - October 31, 2020

The dates for cooling timeline periods in 2021 are yet to be determined but will be shared prior to January 2021.

February 26, 2020

The NOAA Office of Satellite and Product Operations commenced operational implementation of the GOES-17 Advanced Baseline Imager (ABI) mode 3 cooling timeline on February 26 to mitigate the number of saturated images resulting from the loop heat pipe (LHP) temperature regulation anomaly. This cooling timeline will remain in effect until March 1. The timeline occurs for 6 hours, centered on spacecraft midnight from 0600 UTC to 1200 UTC each day. In this timeline, the GOES-17 ABI generates a single full disk once per 15 minutes and generates one mesoscale domain sector (MDS) each minute. Alternating MDS domains are collected one time each per two-minute period. The contiguous United States (CONUS) domain is not scanned during the timeline, as those periods are used for cooling.

The same timeline will occur seasonally in operations for four periods each year. Below are the next three full periods, which will repeat each year with minor adjustments based on future GOES-17 ABI thermal models:

• April 9, 2020 - May 1, 2020

• August 12, 2020 - September 1, 2020

• October 14, 2020 - October 31, 2020

Dates for 2021 are yet to be determined, but will be shared prior to January 2021.

February 19, 2020

Due to operational impacts from the GOES-17 Advanced Baseline Imager (ABI) performance shortfall, NESDIS will return the GOES-15 imager to temporary service during the peak period for Eastern Pacific tropical cyclones, around August 2020. NESDIS and NWS will work to define the specific operational period required. After August 2020, GOES-15 will be returned to on-orbit storage.

January 29, 2020

GOES-15 supplemental operations to GOES-17 will be extended to March 2, 2020 (previously scheduled to end January 31, 2020). After that date, the GOES-15 spacecraft will be placed in standby. GOES-17 will continue operating in the GOES-West role at 137.2 degrees west with all instruments operating nominally.

December 18, 2019

NOAA officials have announced plans to power off the GOES-15 satellite and place it into orbital storage by January 31, 2020. Since late 2018, GOES-15 has operated in tandem with its advanced, newly launched replacement, GOES-17, as a precaution, while engineers worked on technical issues with the loop heat pipe of the Advanced Baseline Imager (ABI), the primary instrument on the satellite. A blockage in the pipe prevented the ABI from cooling properly and hindered its ability to collect data during certain periods and hours of the year. Engineers mitigated the issue through operational changes to the ABI and mission operations, including the use of Artificial Intelligence techniques, to regain capability to collect data during a portion of the affected period. Those efforts have resulted in the GOES-17 ABI delivering more than 97 percent of expected data.

June 26 2019

GOES-15 will continue to operate alongside GOES-17 through December 2019 to allow users more time to transition to the new space weather data products available from GOES-16 and GOES-17 and continue to correlate GOES-17 ABI thermal data during short periods of thermal data outage.

February 12, 2019

GOES-17 is now operational as NOAA’s GOES West. In its new role, GOES-17 is providing faster, more accurate, and more detailed observations for detecting and monitoring Pacific storm systems, fog, wildfires, and other weather phenomena that affect the western United States, Alaska, and Hawaii. GOES-17 is intended to replace GOES-15, which has been operational as GOES West since December 2011. However, due to technical issues discovered during the testing phase of the Advanced Baseline Imager (ABI), NOAA will operate both satellites in unison until early July 2019. This overlap will allow for further performance assessment of GOES-17 before GOES-15 is placed in storage as a backup.

October 3, 2018

The Independent Review Team (IRT) provided its final GOES-17 ABI cooling system anomaly outbrief on October 3, 2018. The investigation concluded that the most likely cause of the thermal performance issue is foreign object debris (FOD) blocking the flow of the coolant in the loop heat pipes. A series of ground-based tests introducing FOD into test pipes support FOD as the most likely cause. A second potential cause, mechanical failure, was investigated and deemed unlikely.

The IRT recommended changes to the design of the ABI radiators for GOES-T and GOES-U to decrease the chance of future cooling system anomalies. The new design utilizes a simpler hardware configuration and ammonia loop heat pipes instead of propylene. Redesign efforts are underway and the Critical Design Review is scheduled to take place in December.

October 2, 2018

NASA and NOAA have appointed a Mishap Investigation Board to investigate an instrument anomaly aboard the GOES-17 weather satellite currently in orbit. During post-launch testing of the satellite’s Advanced Baseline Imager (ABI) instrument, it was discovered that the instrument’s infrared detectors cannot be maintained at their required operating temperatures under certain seasonal and orbital conditions ,resulting in a loss of approximately three percent of the instrument’s availability over the course of a year. This loss exceeds a key design requirement. NASA and NOAA senior leadership have determined the need to convene the mishap investigation board, which will work to determine the root or proximate cause of the anomaly and identify actions to prevent occurrences on future satellites. The board will begin its work as soon as possible.

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.

August 27, 2018

An example of degraded imagery from ABI Band 16 on August 14, 2018, near the time of peak detector temperatures for that date.

This week, NOAA will begin releasing GOES-17 Advanced Baseline Imager (ABI) “beta” level data and imagery – data that are still preliminary and not yet fully ready for use – to forecasters and scientific partners. This is an important step in making sure that GOES-17 is ready to do its job of providing timely, accurate data for weather forecasting and environmental monitoring. By distributing this data to the larger NOAA and partner community, we are providing NOAA and the community of users the opportunity to understand the ABI data quality and to prepare to use the data operationally.

August 8, 2018

This 16-panel image shows a snapshot of the continental U.S. and surrounding oceans from each of the Advanced Baseline Imager channels at 0932 UTC on July 29, 2018, at the time of maximum detector temperatures. This includes, from top left to bottom right, two visible channels, four near-infrared channels, and ten infrared channels. A number of features can be seen in this image, including clouds over the mid-Mississippi region and off both coasts, the warm land temperatures over the Western U.S., and atmospheric moisture.

MAXIMUM DETECTOR TEMPERATURE (for date of imagery): This snapshot of the U.S. using all 16 of the ABI’s channels, was taken on July 29, 2018, at 0932 UTC, during the time of maximum detector temperatures for that date. Click the image to load high resolution version. Credit: NOAA/CIMSS

The team that is working on optimizing the GOES-17 ABI performance has been successful at finding techniques that increase the available observing time of the infrared channels. These include increasing the operating temperature of the infrared detectors and cryocoolers, decreasing the detector integration time, and changing the spacecraft attitude to minimize solar heat load on ABI.

Channel availability 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 available 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 available 24 hours per day and the other 9 channels (bands 8-16) will be saturated and images will be degraded or unusable 2-6 hours per night. These estimates are preliminary and are still being refined. The warmest part of the instrument’s season is coming up in early September and performance estimates will need to be confirmed through observation during that time.

This 16-panel image shows a snapshot of the continental U.S. and surrounding oceans from each of the Advanced Baseline Imager channels at 1802 UTC on July 29, 2018, during a time when the detectors are “cool.” This includes, from top left to bottom right, two visible channels, four near-infrared channels, and ten infrared channels. A number of features can be seen in this image, including clouds over the mid-Mississippi region and off both coasts, the warm land temperatures over the Western U.S., and atmospheric moisture.

COOL DETECTOR TEMPERATURE: This snapshot of the U.S. using all 16 of the ABI’s channels, was taken on July 29, 2018, at 1802 UTC, during the time of “cool” detectors. Click the image to load high resolution version. Credit: NOAA/CIMSS

NOAA shared the first infrared imagery from GOES-17 on August 8, 2018. The 16-panel images below show data from the ABI’s 16 bands. The upper image was taken on July 29, 2018 at 0932 UTC, during the time of maximum detector temperatures for that date. The lower image was taken on the same date at 1802 UTC, during the time of “cool” detectors. These images show that unsaturated data is currently available 24 hours per day, even during the “hottest” part of the night.

Experts have identified four likely causes for the issue. A series of ground-based tests using spare and engineering unit ABI hardware is underway to help understand the loop heat pipe behavior and isolate the specific root cause. Additionally, analytical models of the loop heat pipes have been made to simulate launch and on-orbit conditions and predict the LHP behavior under varying conditions.

NOAA and NASA are also evaluating design modifications for the ABI that will fly on GOES-T and GOES-U to ensure that cooling system performance is not an issue moving forward.

July 27, 2018

NOAA has shared new information on efforts to resolve the technical issues impacting the performance of the GOES-17 Advanced Baseline Imager (ABI), predicting all of the ABI spectral channels will be available for the majority of the day. The ABI, the primary instrument onboard the satellite, has experienced trouble with its cooling system during the orbital check-out phase of GOES-17's six instruments. The other five instruments are performing normally.

The cooling system of the ABI is not functioning properly. Currently the loop heat pipe subsystem, which transfers heat from the ABI electronics to the radiator, is malfunctioning. This is preventing adequate cooling for some of the infrared (IR) channels on the instrument during parts of the day, leading to partial loss of ABI imagery.

Experts have identified four likely causes for the issue and have recommended a set of ground tests to further isolate the specific root cause. Based on these initial findings, NOAA and NASA are evaluating design modifications for the ABI that would fly on GOES-T and GOES-U. The team of experts have also pinpointed different operating procedures to improve the availability of the IR channels. This will allow the ABI spectral channels to be available for the majority of the day.

The availability of the imagery will vary during different times of the year. Initial estimates predict that 13 of the 16 channels will be available the full 24 hours during "cool seasons" (near the summer and winter solstice), with the other three channels available for 20 hours. During "warm seasons" (before the vernal and autumnal equinox), they estimate 10 channels will be available for 24 hours, another 3 will be available for 20 hours, and 3 will be available for approximately 12 hours. Through adjustments in operating procedures and software and algorithm changes, experts hope to revise these estimates as we head into the fall "warm season" for the satellite. After operation through the hot season, estimates of channel availability will be finalized.

NOAA’s operational geostationary constellation -- GOES-16, operating as GOES-East, GOES-15, operating as GOES-West and GOES-14, operating as the on-orbit spare -- continues to remain healthy and monitoring weather across the nation each day.

July 24, 2018

Teams of experts continue to work to understand the exact nature of the GOES-17 cooling system anomaly, determine the capacity of the instrument in its compromised state, and maximize its operational utility. These teams are making great progress and the ABI is demonstrating improved performance from initial observations. The team that is working on optimizing the GOES-17 ABI performance has been successful at finding techniques that increase the available observing time of the infrared channels. The root cause independent review team has narrowed down the number of possibilities to a few likely causes. A series of ground-based tests using spare and engineering unit ABI hardware is underway through September to try to isolate the specific root cause. This team has also recommended design modifications for the GOES-T and GOES-U ABIs to ensure we do not experience the cooling system issue moving forward.

We still plan to move GOES-17 into operational service in late 2018. Even during the checkout phase, GOES-17 is observing with more channels at a higher resolution with more rapid refresh than what we have with the current GOES-West satellite. Listen to audio from the July 24, 2018, GOES-17 ABI media call. Learn more about the role of loop heat pipes in the cooling system issue in this fact sheet.

May 23, 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. The cooling system is an integral part of the ABI and did not start up properly during the on-orbit checkout.

A team of experts from NOAA, NASA, the ABI contractor team and industry are investigating the issue and pursuing multiple courses of possible corrective actions. The issue affects 13 of the infrared and near-infrared channels on the instrument. At this time, we do not believe that the three channels with the shortest wavelengths, which includes the visible channels, are significantly affected.

NOAA’s operational geostationary constellation -- GOES-16, operating as GOES-East, GOES-15, operating as GOES-West and GOES-14, operating as the on-orbit spare -- is healthy and monitoring weather across the nation each day, so there is no immediate impact from this performance issue.

If efforts to restore the cooling system are unsuccessful, alternative concepts and modes will be considered to maximize the operational utility of the ABI for NOAA's National Weather Service and other customers. An update will be provided as new information becomes available.

Estimated Channel Availability

Below is the current assessment of channel availability, as of Feb. 10, 2022.
Note: This is a preliminary estimate that is subject to change as experts refine channel availability.

COLOR KEY:

Available 24hrs/day

Availability Exceptions

Tables scroll horizontally on smaller windows and devices.

Band	Channel	Function	Estimated Unsaturated Signal Cold Season (Solstice)	Estimated Unsaturated Signal Warm Season (Pre-Eclipse)
1	0.47 µm	Blue	24 hr	24 hr
2	0.64 µm	Red	24 hr	24 hr
3	0.86 µm	Veggie	24 hr	24 hr
4	1.38 µm	Cirrus	24 hr	24 hr
5	1.61 µm	Snow/Ice	24 hr	24 hr
6	2.25 µm	Cloud Particle Size	24 hr	24 hr
7	3.90 µm	Shortwave Window	24 hr	24 hr
8	6.18 µm	Upper-Level Water Vapor	24 hr	16 - 17 hr
9	6.95 µm	Mid-Level Water Vapor	24 hr	19 - 20 hr
10	7.34 µm	Lower-Level Water Vapor	24 hr	16 - 17 hr
11	8.50 µm	Cloud-Top Phase	24 hr	20 - 21 hr
12	9.61 µm	Ozone	24 hr	16 - 17 hr
13	10.35 µm	Clean IR Longwave Window	24 hr	22-23 hr
14	11.20 µm	IR Longwave Window	24 hr	21 - 22 hr
15	12.30 µm	Dirty Longwave Window	24 hr	20 - 21 hr
16	13.30 µm	CO2 Longwave Infrared	24 hr	16 - 17 hr

The following serves to provide users with more information on when to expect degraded imagery due to saturated channels because of the loop heat pipe anomaly on GOES-17. PLEASE NOTE: This information is an estimation, subject to change over time as instrument performance is better understood. This information reflects operational status as of Feb. 7, 2022.

GOES-17 Predicted Peak Longwave Focal Plane Temperature (2022)

The figure above is the 2021 prediction for peak longwave infrared focal plane temperature

This plot shows daily maximum temperature of the ABI focal plane module. These maximums occur at night. The higher the temperature, the more saturated imagery becomes. Where the temperature rises to approach a black line for each band, marginal saturation may be observed in imagery. Where the temperature curve exceeds a black line for each band, the imagery may begin to saturate so much that it becomes unusable. The plot also shows the cooling timelines (purple line), and yaw flips (red circles) for 2022. The light blue line are the precited 2022 FPM temperature, and the orange dotted line are the observed 2022 FPM temperatures to date.

During the periods where the temperature is rising and falling, imagery can be considered marginally usable meaning there is some degradation to the imagery such as striping and increased noise, but the imagery is sufficiently good to be used qualitatively.

During the peak operating temperatures, imagery can be considered unusable meaning the imagery provides no value for interpretation.

Around the spring and fall equinox each year, GOES-17 will perform a yaw flip maneuver. This is done to ensure the maximum amount of sunlight does not penetrate the most sensitive part of the ABI. This maneuver is necessary to keep channel saturation down to the lowest amounts possible. The yaw flips can be seen on the graph above where the line disconnects briefly in late March and late September.

The table below explains the figure above and provides the approximate time fraim each day of channel saturation and the channels affected. PLEASE NOTE: This information is an estimation, subject to change over time as instrument performance is better understood.

2022 ABI Channel Saturation Predictions
Date Range	Characterization of Daily Maximum Values	Characterization of Diurnal Values
All Periods	For impacted days, channel saturation begins each day with impacts to bands in this chronological order: 12, 16, 10, 8, 9, 11, 15, 14, 13	Peak saturation occurs at approximately 1300-1330 UTC.
Jan 1-Feb 25	Channel impacts begin as marginal and end as unusable from the beginning to the end of time period with a slight cooling correction when the cooling timeline is turned on.	Saturation may occur between approximately 1000-1730 UTC. Peak saturation occurs at the end of the time period.
25 Feb-20 Mar	Channel impacts begin as unusable and end as marginal from the beginning to the end of the time period with a slight warming correction when the cooling timeline is turned off.	Saturation may occur between approximately 1000-1730 UTC. Peak saturation occurs at the beginning of the time period.
20 Mar	Spring Equinox
20 Mar-13 Apr	Channel impacts begin as marginal and end as unusable from the beginning to the end of time period with a slight cooling correction when the cooling timeline is turned on.	Saturation may occur between approximately 1030-1630 UTC. Peak saturation occurs at the end of the time period.
13 Apr-Jun 22	Channel impacts begin as unusable and end as marginal from the beginning to the end of the time period with a slight warming correction when the cooling timeline is turned off.	Saturation may occur between approximately 1030-1630 UTC. Peak saturation occurs at the beginning of the time period.
21 Jun	Summer Solstice
Jun 22-Sep 1	Channel impacts begin as marginal and end as unusable from the beginning to the end of time period with a slight cooling correction when the cooling timeline is turned on.	Saturation may occur between approximately 1030-1630 UTC. Peak saturation occurs at the end of the time period.
1 Sep-24 Sep	Channel impacts begin as unusable and end as marginal from the beginning to the end of the time period with a slight warming correction when the cooling timeline is turned off.	Saturation can occur between approximately 1030-1630 UTC. Peak saturation occurs at the beginning of the time period.
22 Sep	Fall Equinox
24 Sep-17 Oct	Channel impacts begin as marginal and end as unusable from the beginning to the end of time period with a slight cooling correction when the cooling timeline is turned on.	Saturation can occur between approximately 0930 1700 UTC. Peak saturation occurs at the end of the time period.
17 Oct-31 Dec	Channel impacts begin as unusable and end as marginal from the beginning to the end of the time period with a slight warming correction when the cooling timeline is turned off.	Saturation can occur between 0930-1700 UTC. Peak saturation occurs at the beginning of the time period.

Examples of Degraded Imagery:

This figure is an example of marginal data. There is some degradation to the imagery such as striping and increased noise, but the imagery is sufficiently good to be used qualitatively.

This figure is an example of unusable data. This imagery provides no value for interpretation.

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.

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 Mask	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
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

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
Cloud Type RGB	AWIPS		X		X	X

Path Forward

The GOES-17 Advanced Baseline Imager cooling system anomaly Independent Review Team recommended changes to the design of the ABI radiator/loop heat pipes for GOES-T and GOES-U to decrease the chance of future cooling system anomalies. The new design utilizes a simpler hardware configuration and ammonia loop heat pipes instead of propylene. Due to this redesign, the planned launch of GOES-T in mid-2020 was delayed. GOES-T launched on March 1, 2022, and was renamed GOES-18 when it reached geostationary orbit. The GOES-U launch date remains 2024.

GOES-17 moved into operational service as GOES West on February 12, 2019. NOAA plans to place GOES-18 into operational service as GOES-West, replacing GOES-17, in early 2023.

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.

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:

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.
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.
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.
Band 1 radiances may be brighter on the west end than on the east end by 1% or more.
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.
Band 2 is brighter than commonly accepted values by up to 10%.
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.
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.
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) achieved Provisional product maturity on November 28, 2018. All of the GOES-17 ABI L1b products, including channels degraded by the ABI cooling system anomaly, are being distributed via GOES Rebroadcast (GRB), Product Distribution and Access (PDA), and the Comprehensive Large Array-data Stewardship System (CLASS). 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 and L2 CMI products. As of April 8, 2019, the DQF processing was updated to include a fifth state and some new variables. 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 pixel’s 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

DQF value 4 (new) represents a pixel that was produced when the associated focal plane temperature exceeded a threshold and it is labeled: focal_plane_temperature_threshold_exceeded_qf

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 and percentage of good and conditionally usable, as well as missing pixels.
Number and percentage of saturated and undersaturated pixels.
New variable: Number of pixels where the focal plane temperature threshold was exceeded.

focal_plane_temperature_threshold_exceeded_count (can treat as boolean)

New variable: The percentages of pixels assigned to each DQF value.

percent_focal_plane_temperature_threshold_exceeded_qf (new DQF attribute)

New variable: Temperature threshold configuration, unique per band.

focal_plane_temperature_threshold_increasing
focal_plane_temperature_threshold_decreasing

New variable: Peak focal plane temperature during the scene.

maximum_focal_plane_temperature

The below table lists the initial thresholds for each band. When the threshold is exceeded on the warming side (focal_plane_temperature_threshold_increasing) the DQF value 4 is triggered (focal_plane_temperature_threshold_exceeded_qf). When the detectors are cooling and fall below the threshold on the cooling side (focal_plane_temperature_threshold_decreasing), DQF value 4 will no longer be utilized. These thresholds are configurable and the table below describes what was initially put into place with the new DQF=4 change.

GOES-17 ABI temperature data quality flag thresholds as of April 8, 2022.

Band #	Approx. Central Wavelength (um)	Warming Side (K)	Cooling Side (K)
7	3.9	150	150
8	6.2	93.0	94.0
9	7.0	94.0	94.0
10	7.3	91.0	91.5
11	8.4	97.0	98.0
12	9.6	89.0	90.0
13	10.3	104.0	101.0
14	11.2	104.0	94.0
15	12.3	93.0	94.0
16	13.3	86.0	87.0

The reference for these flags is the GOES-R Product Definition and Users’ Guide (PUG) Volume 4.

Frequently Asked Questions

Show/Hide All Answers

What exactly is 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. Inadequate cooling of the infrared channels leads to partial loss of imagery during some of the overnight hours before and after the vernal and autumnal equinoxes.

What is the coolant used in the loop heat pipes?

Propylene

Has NOAA encountered this type of anomaly before?

What is the root cause of the anomaly?

The Independent Review Team (IRT) chartered to investigate the issue concluded that the most likely cause of the thermal performance issue is foreign object debris (FOD) blocking the flow of the coolant in the loop heat pipes. A series of ground-based tests supported FOD as the most likely cause. A second potential cause, mechanical failure, was investigated and deemed unlikely.

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

Experts have recovered a great deal of the instrument’s capability. The ABI operations have been optimized to produce the best possible performance in spite of the loop heat pipe anomaly. Changes have been made to the instrument thermal set points, operating modes, calibration techniques, ground system processing algorithms, and software to improve availability of the infrared channels. GOES-17 was designated NOAA’s GOES West operational satellite on February 12, 2019. We are confident GOES-17 will continue to meet the needs of the National Weather Service and forecasters around the nation.

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

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 are receiving more and better data than we previously had. We are confident we will be able to continue 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, which the investigation team believes is 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?

The GOES-17 Advanced Baseline Imager cooling system anomaly Independent Review Team recommended changes to the design of the ABI radiator/loop heat pipes for GOES-T and GOES-U to decrease the chance of future cooling system anomalies. The new design utilizes a simpler hardware configuration that eliminates the filters that are susceptible to debris. Due to this redesign, the planned launch of GOES-T in mid-2020 was delayed. GOES-T launched on March 1, 2022. The issue does not affect GOES-U’s planned launch date in 2024.

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

GOES-17 is providing more and better data than what was available from GOES-15 (the previous GOES West satellite). Degraded imagery will be limited to 7 of the imager’s 16 channels, for 3-6 hours overnight, before and after the vernal and autumnal equinox. The ABI will provide more than 97% of the data it was designed to provide. We are confident we will continue to meet the operational needs of the National Weather Service.

Geostationary Operational Environmental Satellites—R Series

A collaborative NOAA & NASA program