GSICS Users Workshop 2019

The GSICS Users Workshop 2019 was organized a part of ITSC-XXII in San Savur Canada on 1 Nov 2019. The meeting had over 50 attendees and 10 talks. Talks covered various topics relevant to the application of GSICS algorithms and products in IR VIS MW and UV wavelengths.

Talk1. Mitch Goldberg, GSICS EP Chair started the meeting by providing an introduction about the GSICS. The introduction included purpose, history of GSICS and showed how GSICS style instrument monitoring is critical to the users of Earth Observation data. Channels of GSICS knowledge and data sharing included GSICS product catalog, GSICS Newsletter and the yearly State of Observing System report that GSICS Delivers to the CGMS. This report summarizes the performance of each instrument monitoring by the individual GPRCs. Mitch further indicated GSICS forays into the WMO Integrated Observing System ( wigos). GSICS is now a component of the WIGOS and has prepared documents that are currently being reviewed by the WIGOS.

Talk2. Dave Tobin from the University of Wisconsin is a key member of the CrIS calibration team. CrIS is used by the GSICS community as a in-orbit reference for the IR instruments. He spoke about the attributes of a GSICS reference instrument. Dave's talk touched on a very important topic in GSICS community i.e the selection of In-orbit references. Dave suggested a set of attributes that can help decide on a reference instrument.

Talk3. Dorothea Coppins from EUMETSAT gave a talk focused on GSICS IR inter-calibration activities. The three main GSICS IR products include Classical GSICS Products, GSICS Prime Product, GSICS IR Reference and Future GSICS Products . Dorothea provided an overview of recent changes to processing to IASI-A after it entered its end of life phase. She suggested GSICS members to switch to IASI-B or IASI-C as reference. In summary the IASI-A has the following behaviour currently.

• SWIR: V. small positive differences (<<0.1K)
• MWIR: V. small positive differences (<<0.1K)
• LWIR window: Small negative differences (<~0.1K)
• LWIR absorption: Larger negative differences (<~0.3K)

In the future KMA and CMA are expected to provide intercalibration products of AMI and FY-3.

Talk4. Tiger Yang from NOAA gave an overview of Lunar Calibration. His talk touched on various key issues, A key issue for microwave cubesats and small satellite constellation is a consistency calibration algorithm. Permanent Reference Target (PRT) with high stability and well-known microwave brightness temperature can not only help to evaluate the instrument calibration accuracy, it can also being used to evaluate the long-term calibration stability of microwave sensors. Radiation of the Moon is very stable in microwave spectrum, attribute to its stable geophysical property. The only factors that change the magnitude of lunar microwave radiation in satellite observations are its surface temperature, which is determined by its phase angle, and its position in the Field of View (FOV). Therefore, there is potential to take the Moon as PRT to evaluate the calibration accuracy and assess the long-term calibration stability for microwave radiometers. In this study, microwave brightness temperature simulation model for moon’s disk was developed and validated based on ATMS space view observations. To demonstrate the effectiveness of proposed lunar calibration model, 5 years lunar observations from NPP ATMS were collected and evaluated by the model simulations. Results show that ATMS calibration accuracy and stability can be well assessed by taking the moon as a reference calibration target

 

Talk5: Qifen Lu (CMA, Co-Chair GSICS MW Subgroup) ( MW Subgroup Co-Chair) shared the vision of the GSICS Microwave Subgroup. Lu. Mark gave the scope of the GSICS MW subgroup. A key was to understand user requirements for monitoring and CDR creation. Sharing of tools such as SNO, Double Difference, RTM as the near term goals. Lu also spoke about the response of the GSICS MW subgroup to the CGMS actions to organize the expert meeting on the inter-calibration of operational PMW sensors to meet the WIGOS targets of 2040. He stated that the CEOS WGCV MWSC meeting In Darmstadt and the GSICS Annual Meeting in Frascati 2019 organized the expert meeting. Qifeng then also laid out the plan for generating MW NRT GSICS products. He stressed on explaning the MW Subgroup activities and strenthenig its connect with the groups such as GPM-X, CEOS, ISWG.

Talk 6: Bomin Sun provided an overview of the progress using GRUAN observations to monitor Satellite Infrared and Microwave Sensors.

The Global Climate Observing System (GCOS) Reference Upper Air Network (GRUAN) is a reference observing network designed to provide fully characterized data records for upper-air climate change detection. A concerted effort to utilize GRUAN to supplement the Global Space-based Inter-Calibration System (GSICS) in the monitoring and assessment of environmental satellite sensors was initiated at the GSICS Annual meeting in 2017. Those sensors include the Cross-track Infrared Sounder (CrIS), the Infrared Atmospheric Sounding Interferometer (IASI), the High-resolution Radiation Sounder (HIRS), the Advanced Technology Microwave Sounder (ATMS) and the Advanced Microwave Sounding Unit (AMSU).

In this work, the feasibility of using GRUAN observations to monitor satellite sensor data are explored in two areas. One is to compare the GRUAN temperature observations with polar satellite microwave data in trends and inter-annual variability. The satellite microwave dataset includes calibrated fundamental Climate Data Records (FCDRs) generated by NOAA Center for Satellite Applications and Research (STAR). The second is to understand the consistency of GRUAN radiosonde humidity observations with satellite water vapor sensitive sensor data. This is achieved by using Radiative Transfer Model (RTM) simulation to convert GRUAN atmospheric profiles into the radiance space for comparison with collocated hyperspectral infrared sensor data. Collocation uncertainty and uncertainty in satellite sensor, GRUAN and RT model are taken into account in the assessment.

This work supports GSICS and GRUAN objectives to monitor microwave and infrared sensors from space-based platforms including the determination of absolute accuracy of the sensors.

Talk 7: Viju John, FIDUCEO expert from EUMETSAT provided an important overview of the algorithms and data the FIDUCEO team used to produce Climate Data Records from Satellite observations. He mentioned that one of the main objectives of the FIDUCEO was to develop a widely applicable metrology framework for Earth Observation to establish traceable uncertainty and Climate information and subsequently develop climate Data records. At the heart of the algorithm of generating FCDR lies the Measurement Function Centered Analysis. This is a cost function that minimizes the differences between observing platforms. He gave an overview of the Harmonization, Spectral Shifts and Uncertainty estimates used by the FIDUCEO. The FIDUCEO project generated AVHRR FCVDR, HIRS FCDR MW Sounde FCDR and Meteosat FCDR. Viju provided suggestions to the GSICS community that can help find uses of GSICS products and algorithms. Suggestions include

•Not starting at count level will limit a fiduceo style analysis;

•Knowledge transfer: how can it continue? Can GSICS adapt FIDUCEO methods?

•FIDUCEO highlights inter-channel correlations to be considered;

Request for open availability of GSICS matchup databases and inter-calibration code

Talk 8: Cheng-Zhi Zou from NOAA provided an overview of the JPSS/SNPP reprocessing of the ATMS. The goal of the reprocessing of the SDR was to update initial calibration algorithms update and apply a unified calibration algorithm to generate consistent SDR. The main benefits were an improvement in EDR and gather building blocks of Climate data records and climate trend analysis. Cheng Zhi provided that new ATMS SDR is available in addition to CrIS VIIRS and OMPS. Presently over 6 years of SNPP SDR has been reprocessed and a software repository for the reprocessing system has been developed

Talk 9 a/b: The last two talks were given by Manik Bali and Lawrence E Flynn from GSICS Coordination Center. These talks were dedicated to GSICS Products, Deliverables, Inter-operability platform and the ways in which one could participate in GSICS. Manik mentioned that GSICS has over 60 products in VIS and IR wavebands and four delierables spanning VIS, IR, and MW. The GSICS Products can be accessed https://www.star.nesdis.noaa.gov/smcd/GCC/ProductCatalog.php and the deliverables can be accessed via the GSICS Wiki. He mentioned about building a new inter-operability platform that combines TYPHON, PYGAC, PTROLL, SATPY and ARTS model that has the ability to intercompare different observing platforms (e.e GRUAN Vs GSICS). Lawrence E Flynn mentioned various pathways by which one could connect with GSICS activities and participate in them. These include Quarterly Newsletter, Product Catalog, GSICS Wiki and the information Kiosk maintained by GCC.

Chair: Lawrence E Flynn and Manik Bali
Talk	Title	Author	Affiliation
Talk1	GSICS purpose, history, and future	Mitch Goldberg	NOAA
Talk2	GSICS Reference Sensor Attributes	Dave Tobin	UWSC
Talk3	GSICS Products for IR Imagers and Sounders	D. Coppens	EUMETSAT
Talk4	On Developing a SI-Traceable Moon Surface Microwave Emission Model Based on Well Calibrated ATMS/AMSU Observations	Hu Yang	CISSES/NOAA
Talk5	GSICS Methods to improve Microwave Sensors	Qifeng Lu	CMA
Talk6	Progress using GRUAN observations to monitor Satellite Infrared and Microwave Sensors (Preliminary Results)	Bomin Sun	NOAA
Talk7	FIDUCEO achievements and the feedback	Viju John	EUMETSAT
Talk8	The reprocessed SNPP / JPSS satellite observations	Cheng-Zhi Zou	NOAA
Talk9.a	GSICS Products and Their Uses	Manik Bali	CISSES/NOAA
Talk9.b	Participating in GSICS: Why, How, When and Where?	Lawrence E Flynn	NOAA

The discussions in the meeting lead to some key actions.

Actions

A.GCC.2019.11.1: Bomin Sun to provide D. Coppens(EUMETSAT) a sample IASI L1C file that would check if the file has the cloud information.

A.GMW.2019.11.2 : Qifeng Lu(CMA) and Viju John (EUMETSAT) to provide content and feedback to the Microwave Reference document shared by Manik Bali

A.GCC.2019.11.3: GCC to organize a GSICS Product Users session in the Annual Meeting and share GSICS product User feedback with the product developers.

A.GCC.2019.11.4: GCC ( Manik Bali) to share with Dave Tobin the Reference Selection Criterion and help draft NOAA response to the IRRefUTable report and SI Traceability report