Subject: Administrative: Status of GOES-16 ABI L1b and CMI data, --00000000000058c36b056fb64625 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable *Topic: Status of GOES-16 ABI L1b and CMI dataDate/Time Issued: June 28, 2018 1630 UTCProduct(s) or Data Impacted: GOES-16 ABI L1b and CMI dataDate/Time of Initial Impact: June 1, 2018 at 2215 UTCDate/Time of Expected End: N/ALength of Event: N/ADetails/Specifics of Change: The GOES-R Peer/Stakeholder Product Validation Review (PS-PVR) for the Advanced Baseline Imager (ABI) L1b and Cloud and Moisture Imagery (CMI) Full Maturity was held on June 1, 2018. As a result of this review, the ABI L1b and CMI products are declared fully mature. The ABI L1b 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, as well as certain instrument calibration and engineering data. The CMI data products are reflectances for bands 1-6 and brightness temperatures for bands 7-16. A full description including format of the ABI L1b product can be found in the Product Definition and User=E2= =80=99s Guide (PUG) document (https://www.goes-r.gov/users/docs/PUG-L1b-vol3.pdf ). A full description including format of the CMI product can also be found in the PUG document (http://www.goes-r.gov/products/docs/PUG-L2+-vol5.pdf ). The algorithm used to derive the CMI product from GOES-16 ABI observations is described in detail in the =E2=80=9CGOES-R Advanced Baseline Imager (ABI) Algorithm Theoretical Basis Document for Cloud and Moisture Imagery Product=E2=80=9D (https://www.goes-r.gov/products/ATBDs/baseline/Imagery_v2.0_no_color.pdf )= . Full Validation maturity, by definition, means the following: - Validation, QA, and anomaly resolution activities are ongoing.- Incremental product improvements may still be occurring.- Users are engaged and user feedback is assessed.- Product performance for all products is defined and documented over a wide range of representative conditions via ongoing ground-truth and validation efforts.- Products are operationally optimized, as necessary, considering mission parameters of cost, schedule, and technical competence as compared to user expectations.- All known product anomalies are documented and shared with the user community.- Product is operational. Users of the GOES-16 ABI L1b and CMI products bear responsibility for inspecting the data and understanding the known caveats prior to use. Below is the list of caveats that have been identified and are under analysis. Solutions are in development and testing: 1. The 0.64 =CE=BCm channel (band 2) is ~7% brighter than commonly accepted values and exceeds the requirement of 5% accuracy.2. There is striping in the 11.2 =CE= =BCm channel (band 14) and, to less extent, the 12.0 =CE=BCm channel (band 15) a= nd 13.3 =CE=BCm channel (band 16). These stripes may exist all the time but be= come weaker for scenes with brightness temperature closer to 300 K. Users may notice this anomaly when viewing the relevant images or use the data quantitatively.3. Low-level striping exists in the 1.61 =CE=BCm channel (ba= nd 5). The cause is believed to be similar to the striping that previously affected bands 1-3 and a similar correction is in work.4. In rare cases, sunlight can reach the ABI by refraction of the Earth=E2=80=99s atmosphere.= It occurs once per year, for less than 1 minute, but when it occurs it effects all channels. The same impact is seen in the VNIR and IR channels during eclipse season (approximately 40 days before and after the vernal [on or about March 21] and autumnal [on or about September 21] equinoxes for approximately 45 minutes before and after satellite local midnight). See http://www.ospo.noaa.gov/Operations/GOES/eclipse.html for additional information.5. In the 3.9 =CE=BCm channel (band 7), some pixels around targ= et of high radiance (such as fire) often have a cold bias. These affected pixels are often one pixel away from the hot target, and the bias is loosely proportional to the target radiance. For pixels saturated by fire, for example, some affected pixels may report zero or negative radiance. While the severe (saturated) cases are rare (perhaps on the order of one out of a million), it is believed that they always cause severe cold bias. For the less severe and more common cases of hot target, the bias is believed to also exist, even though the bias is so small that it is often overlooked.6. If one detector within the hundreds in the array should fail, there may be severe striping in the affected channels. A replacement detector will be identified and a full mitigation made within a few days.7. It is possible for a detector to experience a sudden change in characteristics, although it is still functioning in the valid range. The calibration algorithm can mistake this sudden change as invalid and =E2=80=9Clatch=E2=80=9D to the pr= evious value creating a subtle stripe. This can happen in any channel. It happened a few times in the past year and was corrected within a few days.8. All IR channels have a cold bias of about 0.2 K. This does not exceed the accuracy requirement of 1 K. A recent update was made to mitigate this issue and evaluation is in progress.9. Due to the design of ABI=E2=80=99s focal plane= array, bright object avoidance (BOA) effects each band differently. Using multiple bands should be done carefully because there could be missing data in one band but not another.10. Metadata often arrives for CMI files via GRB before the entire file is delivered.11. There is a drift in the image start/end time which currently resets approximately every two weeks.12. Due to the Planck relationship at 3.9 =CE=BCm in brightness temperature space, = care should be taken for enhancements of cold clouds, so that the noise is not amplified. The full validation README with comprehensive a product quality description will be available on the NCEI website (https://www.ncdc.noaa.gov/data-access/satellite-data/goes-r-series-satelli= tes ) in the coming weeks. Contact for further information: OSPO User Services at SPSD.UserServices@noaa.gov Contacts for specific information on the ABI L1b data product:Elizabeth Kline elizabeth.kline@noaa.gov Fred Wu xiangqian.wu@noaa.gov Contacts for specific information on the ABI CMI product:Wayne MacKenzie wayne.mackenzie@noaa.gov Tim Schmit tim.j.schmit@noaa.gov Jaime Daniels jaime.daniels@noaa.gov Web Site(s) for applicable information: See http://www.ospo.noaa.gov/Operations/messages.html for this and other satellite related messages. See http://www.goes-r.gov/spacesegment/abi.html for ABI specific information.This message was sent from ESPC.Notification@noaa.gov . You have been sent this and other notifications because you have opted in to receive it. If for any reason, you wish to unsubscribe, please contact ESPC Help Desk at ESPCOperations@noaa.gov or (301) 817-3880. Please note: it may take up to two business days to process your unsubscribe request.* <301-286-3647> --00000000000058c36b056fb64625 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

Topic: Status of GOES-16 ABI L1b and C= MI data

Date/Time Issued: June 28, 2018 1630 UTC<= /p>

Product(s) or Data Impacted: GOES-16 ABI L1b and CMI data

Date/Time of Initial Impact: June 1, 2018 at 2215 UTC

Dat= e/Time of Expected End: =C2=A0N/A

Length of Event: =C2=A0N/A


Details/Specifics of Change: The GOES-R Peer/Stakeholder Product Validation Review (PS-PVR) for the Adv= anced Baseline Imager (ABI) L1b and Cloud and Moisture Imagery (CMI) Full M= aturity was held on June 1, 2018. As a result of this review, the ABI L1b a= nd CMI products are declared fully mature.

=C2=A0

The ABI L1b data pr= oducts are calibrated and geo-located radiances of the 16 ABI bands over th= e Full Disk (FD) of the Earth, the Continental United States (CONUS) region= , the Mesoscale (MESO) regions, as well as certain instrument calibration a= nd engineering data. The CMI data products are reflectances for bands 1-6 a= nd brightness temperatures for bands 7-16.

A full description includin= g format of the ABI L1b product can be found in the Product Definition and = User=E2=80=99s Guide (PUG) document (https://www.goes-r.gov/user= s/docs/PUG-L1b-vol3.pdf). A full description including format of the CMI product can a= lso be found in the PUG document (http://www.goes-r.gov/product= s/docs/PUG-L2+-vol5.pdf). The algorithm used to derive the CMI product from GOES-16 AB= I observations is described in detail in the =E2=80=9CGOES-R Advanced Basel= ine Imager (ABI) Algorithm Theoretical Basis Document for Cloud and Moistur= e Imagery Product=E2=80=9D (https://www.goe= s-r.gov/products/ATBDs/baseline/Imagery_v2.0_no_color.pdf).

=C2=A0

Full Validation mat= urity, by definition, means the following:

  • Validation, QA, and anomaly resol= ution activities are ongoing.

  • Incremental pr= oduct improvements may still be occurring.

  • U= sers are engaged and user feedback is assessed.

  • Product performance for all products is defined and documented over a= wide range of representative conditions via ongoing ground-truth and valid= ation efforts.

  • Products are operationally op= timized, as necessary, considering mission parameters of cost, schedule, an= d technical competence as compared to user expectations.

  • All known product anomalies are documented and shared with the= user community.

  • Product is operational.

=C2=A0

User= s of the GOES-16 ABI L1b and CMI products bear responsibility for inspectin= g the data and understanding the known caveats prior to use. Below is the l= ist of caveats tha= t have been identified and are under analysis. Solutions are in development= and testing:

  1. The= 0.64 =CE=BCm channel (band 2) is ~7% brighter than commonly accepted value= s and exceeds the requirement of 5% accuracy.

  2. There is striping in the 11.2 =CE=BC= m channel (band 14) and, to less extent, the 12.0 =CE=BCm channel (band 15)= and 13.3 =CE=BCm channel (band 16). These stripes may exist all the time b= ut become weaker for scenes with brightness temperature closer to 300 K. Us= ers may notice this anomaly when viewing the relevant images or use the dat= a quantitatively.

  3. Low-level striping exists in the 1.61 =CE=BCm channel (band 5). The cause is believed to be similar = to the striping that previously affected bands 1-3 and a similar correction= is in work.

  4. In rare cases, sunlight can reach the ABI by refraction of the Earth= =E2=80=99s atmosphere. It occurs once per year, for less than 1 minute, but= when it occurs it effects all channels. The same impact is seen in the VNI= R and IR channels during eclipse season (approximately 40 days before and a= fter the vernal [on or about March 21] and autumnal [on or about September = 21] equinoxes for approximately 45 minutes before and after satellite local= midnight). See http://www.ospo.noaa.gov/Operations/GOES/eclip= se.html for= additional information.

  5. In the 3.9 =CE=BCm channel (band 7), some pixels around t= arget of high radiance (such as fire) often have a cold bias. These affecte= d pixels are often one pixel away from the hot target, and the bias is loos= ely proportional to the target radiance. For pixels saturated by fire, for = example, some affected pixels may report zero or negative radiance. While t= he severe (saturated) cases are rare (perhaps on the order of one out of a = million), it is believed that they always cause severe cold bias. For the l= ess severe and more common cases of hot target, the bias is believed to als= o exist, even though the bias is so small that it is often overlooked.

  6. If one dete= ctor within the hundreds in the array should fail, there may be severe stri= ping in the affected channels. A replacement detector will be identified an= d a full mitigation made within a few days.

  7. It is possible for a detector to exper= ience a sudden change in characteristics, although it is still functioning = in the valid range. The calibration algorithm can mistake this sudden chang= e as invalid and =E2=80=9Clatch=E2=80=9D to the previous value creating a s= ubtle stripe. This can happen in any channel. It happened a few times in th= e past year and was corrected within a few days.

  8. All IR channels have a cold bias = of about 0.2 K. This does not exceed the accuracy requirement of 1 K. A rec= ent update was made to mitigate this issue and evaluation is in progress.

  9. Due to t= he design of ABI=E2=80=99s focal plane array, bright object avoidance (BOA)= effects each band differently. Using multiple bands should be done careful= ly because there could be missing data in one band but not another.<= /p>

  10. Metadata often= arrives for CMI files via GRB before the entire file is delivered.<= /p>

  11. There is a dri= ft in the image start/end time which currently resets approximately every t= wo weeks.

  12. Due to the Planck relationship at 3.9 =CE=BCm in brightness temperature= space, care should be taken for enhancements of cold clouds, so that the n= oise is not amplified.

=C2=A0

The full validati= on README with comprehensive a product quality description will be availabl= e on the NCEI website (https://www.ncd= c.noaa.gov/data-access/satellite-data/goes-r-series-satellites) in the coming weeks.

=C2=A0

Contact for further information: OSPO User Services at SPSD.UserServices@noa= a.gov

Contacts for specific information on the ABI= L1b data product:

Elizabeth Kline elizabeth.kline@noaa.gov

Fred Wu xiangqian.wu@noaa.gov


Cont= acts for specific information on the ABI CMI product:

= Wayne MacKenzie wayne.mackenzie@noaa.gov

Tim Schmit = tim.j.schmit@noaa.g= ov

Jaime Daniels jaime.daniels@noaa.gov


Web Site(s) for appli= cable information: See http://www.ospo.noaa.gov/Operations/message= s.html for = this and other satellite related messages. See http://www.goes-r.gov/spa= cesegment/abi.html for ABI specific information.


This message was sent from ESPC.Notification@noaa.gov. You have been sent this and other notificati= ons because you have opted in to receive it. If for any reason, you wish to= unsubscribe, please contact ESPC Help Desk at ESPCOperations@noaa.gov or (301) 817-3880. Please note: it may take up to two business days to process your unsubs= cribe request.



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