The Hyperspectral Imager SUIte (HISUI) is being developed by Japanese Ministry of Economy, Trade, and Industry (METI), which was successfully launched to the International Space Station (ISS) dated on Dec 5, 2019. HISUI Level 1G product is the orthorectified top-of-atmosphere spectral radiance product, and available free of charge from October 12, 2022. This research shows preliminary radiometric performance evaluation of ISS HISUI using satellite-based and ground-based data.

The hyperspectral imager suite (HISUI) is a recently commissioned spaceborne hyperspectral sensor that is expected to provide higher-quality information for terrestrial and aquatic monitoring at a global scale. To maximize the utility of the detailed spectra observed by HISUI, calibration and validation activities have been intensively conducted for the past several years. However, research on long-term monitoring of sensor radiometric characteristics and checking inter-band radiometric consistency is still limited. This study provided the first results of cross- and inter-band calibrations using five scenes acquired over a desert calibration site during 2021–2023, and calculated relative cross-calibration coefficients (RCCCs) to calibrate all the HISUI bands. To make full use of the limited amount of data archived over the calibration site, off-nadir scenes obtained by wide-swath counterpart sensors [i.e., the moderate resolution imaging spectroradiometer (MODIS)] were used for the cross-calibration, with correction by a bidirectional reflectance distribution function. The obtained RCCCs successfully mitigated the inter-band radiometric variability of HISUI data, which was consistent with the in situ surface reflectance data observed by the radiometric calibration network (RadCalNet). Time-series analysis further revealed a notable discrepancy between the visible to near-infrared and short-wave infrared (SWIR) spectral domains after the International Space Station (ISS) maneuvers in spring 2022. This article is also a prompt report of this phenomenon and will soon contribute to HISUI radiometric calibration, particularly after the maneuver events.

Hyperspectral Imager Suite (HISUI) was launched in December 2019 and started its operation observation from International Space Station in October 2020. HISUI data are being acquired based on data acquisition requests from HISUI project and principal investigators of HISUI Research Announcement. The total area of acquired HISUI data by December 2021 exceeded 110 M km2and the data are being used in various application studies. HISUI will be operated by FY2023. In this presentation, HISUI's instrument and operation status will be presented together with its early results in terms of geology and greenhouse gas emission.

The vicarious calibration for the Advanced Spaceborne Ther-mal Emission and Reflection Radiometer (ASTER) onboard Terra satellite had been conducted for more than 20 years. ASTER Level 1 products has started to be processed and generated by the latest ASTER radiometric database ver5 in 2021. We validated the latest ASTER VNIR bands (Band1, band2, and Band3N) radiometric performance using ASTER vicarious calibration experiments and the Radiometric Cali-bration Test Site (RadCaTS) results obtained for the period 2014 to 2019.

We assessed the degradation of the radiance lamp in the onboard calibration system of the Spectral Profiler, a hyperspectral sensor onboard the Japanese Selenological and Engineering Explorer (SELENE), which was launched in September 2007 and observed the Moon until June 2009. We found that the output of the radiance lamp soon after launch increased by 3.2%–4.6% as compared with the prelaunch output, after which it decreased over time. The total decrease during the mission lifetime of about 1.5 years after the increase of 3.2%–4.6% was ~1.1%–1.5%, which is slightly larger than the$0.8\,\mu \text{m}$. The trend of the wavelength dependence was shown to be consistent with a model of blackbody radiance with a decrease in temperature of the lamp of about −5 K, suggesting that the degradation of the lamp was mostly due to temperature decrease of about −3 K/yr. Our results may provide an important constraint on the quantitative assessment of the degradation of the sensitivity of remote-sensing sensors using an onboard calibration system, such as the Advanced Spaceborne Thermal Emission and Reflection Radiometer.

This paper reports on the initial analysis of spectral smile calibration of the Hyperspectral Imager Suite (HISUI) onboard the International Space Station, which has been continuously acquiring data since September 4, 2020. HISUI is an optical hyperspectral imager consisting of two subsystems: VNIR covering 400 to 980nm at intervals of 10 nm, and SWIR covering 895 to 2481nm at 12.5nm intervals. Based on the atmospheric correction for actual observation images, we assessed cross-track dependences of the wavelength deviation (spectral smile) and the full-width at half-maximum (FWHM) of the HISUI response function. We found that significant spectral smile was observed, with maximum variations of 1.8nm in VNIR and 4.3–4.5nm in SWIR. In addition, the cross-track variation of FWHM was observed with maximum variations of 5.0nm for VNIR and 2.5–3.5nm for SWIR.We used the results to model the smile functions to update a smile correction table in the internal calibration system of HISUI. Then, we evaluated how the smile functions reduce the spectral smile in the data acquired after the update on September 27, 2021.We confirmed that VNIR showed a nearly flat profile within 0.25nm with a nearly constant FWHM. For SWIR, although a slight amount of spectral smile and a variation of FWHM were still observed partly due to wavelength dependence in the spectral smile, the spectral smile was reduced to <~2.2 nm. This study demonstrated that wavelength calibration using actual observation images for ground surfaces is important for the characterization of hyperspectral sensors.

Hyperspectral Imager Suite (HISUI) was launched in December 2019 and successfully attached to Japan Experiment Module Exposed Facility, International Space Station. Due to data communication problems, its initial check out activities have been delayed, but its first light image was acquired and released in September 2020. HISUI data delivery to Research Users will start in 1Q of Japanese FY2021 (April - June 2021).

HISUI, the Japanese hyperspectral sensor, was launched on December 6, 2019 and the first image was taken on September 4, 2020. The first HISUI calibration was conducted on September 11. Wavelength and radiance calibration were conducted to evaluate characteristic change during the launch process. We found 2.3 nm and 5.5 nm wavelength shifts for VNIR and SWIR, respectively using SRM2025a filter onboard HISUI calibration system. Sensitivity changes during the launch process were less than 1.0 % that is smaller than the radiometric accuracy specifications.

Hyperspectral Imager Suite (HISUI) was launched on Dec. 5, 2019 and successfully attached to Japan Experiment Module Exposed Facility, International Space Station. Currently, initial check out activities are ongoing, and the first light images will be released around August, 2020. The distribution of HISUI Level 1 products will be started in the first half of 2021.

ASTER, which is a multi-band pushbroom sensor onboard Terra, has provided worthful multiband images for approximately 20 years successfully since Terra's launch in 1999. For such a long operation, maintaining accurate radiometric calibration is an important challenge to guarantee the reliability of the satellite products. In April 2003 and August 2017, ASTER observed the Moon (and deepspace) for conducting radiometric calibration with the Moon, which is called as lunar calibration. Through the lunar calibration, temporal variation of relative sensor sensitivity can be measured accurately (the order of 0.1 %), which is reasonably accurate to improve calibration results from other methods. The lunar calibration was performed to ASTER's visible and near infrared bands (Band 1, Band 2, and Band 3N) by comparing the observed brightness with simulated lunar brightness. 3, 5, and 6% sensitivity degradation were observed in Band 1, Band 2, and Band 3N of ASTER, respectively, which are basically consistent with vicarious calibration, though still further discussion is needed for combining calibration results from different methods.

Hyperspectral Imager Suite (HISUI) is a future spaceborne hyperspectral Earth imaging system being developed by Japanese Ministry of Economy, Trade, and Industry (METI). HISUI will be launched and deployed on International Space Station (ISS) for two - three year operation from 2020. Manufacturing and testing of Hyperspectral sensor were completed. Integration and test of HISUI Exposed Payload System is being conducted. HISUI data policy and research announcement as well as synergy with other earth observing instruments onboard ISS are also being discussed.

Higher level products derived from satellite optical sensor data is affected by the accuracy of surface reflectance product. The HISUI will be launched to International Space Station (ISS) Japan Experiment Module (JEM) in FY2019, and surface reflectance product (L2G) will be also generated as research products. We have three validation sites for HISUI L2G validation in Japan, which are installed the automated facility systems for atmospheric parameters. This research shows the aerosol properties over validation sites in Japan on one of the HISUI calibration and validation activities.ppp.

Hyperspectral Imager Suite (HISUI) is a future spaceborne hyperspectral Earth imaging system being developed by Japanese Ministry of Economy, Trade, and Industry (METI). HISUI will be launched and deployed on International Space Station (ISS) for two - three year operation from 2020. Manufacturing and testing of HISUI Flight Model were almost completed, and design of HISUI Exposed Payload System is being conducted. HISUI data policy and research announcement as well as synergy with other earth observing instruments onboard ISS are also being discussed.

The HISUI Hyperspectral Imager is being developed by Japanese Ministry of Economy, Trade, and Industry (METI), which will deploy on International Space Station (ISS) Japan Experiment Module (JEM) in FY2019. HISUI Level 2 surface reflectance product (L2G) will be also provided for each of the VNIR and SWIR bands as research products. We have a plan of HISUI L2G validation, which includes not only surface reflectance itself also the atmospheric parameters, especially aerosol properties. We already have 3 sites that measures the atmospheric parameters day by day. This research shows the aerosol properties over validation sites in Japan on one of the HISUI calibration and validation activities.

Hyperspectral Imager Suite (HISUI) is a future spaceborne hyperspectral Earth imaging system being developed by Japanese Ministry of Economy, Trade, and Industry (METI). HISUI will be launched and deployed on International Space Station (ISS) for three year operation from 2019. In FY2016, manufacturing and testing of HISUI Flight Model and design of HISUI Exposed Payload System were conducted. HISUI data policy and research announcement as well as synergy with other earth observing instruments onboard ISS are also being discussed.

Hyperspectral Imager Suite (HISUI) is a future spaceborne hyperspectral Earth imaging system being developed by Japanese Ministry of Economy, Trade, and Industry (METI). HISUI project is currently being promoted by three organizations each of which has a contract with METI together with several scientists from universities and national research institutes. Recently, it was decided to deploy HISUI on International Space Station. The current status of HISUI project will be introduced in the presentation.

The hyperspectral imager of the HISUI (Hyperspectral Imager Suite) project will be deployed and operated in the International Space Station (ISS) Japanese Experiment Module-Exposed Facility (JEM-EF) in FY2018. The pre-launch calibration is conducted using a large integrating sphere traceable to the SI, and after the launch, the onboard calibration will be carried out using onboard calibration unit including a lamp. The vicarious calibration will be conducted over the dry lake sites located both in northern hemisphere and in southern hemisphere, and we may also use automated calibration facilities due to the effects of orbital characteristics for the ISS. The HISUI hyperspectral imager will be cross-calibrated using forthcoming hyperspectral sensors flying on ISS. The data associated with these calibrations will be archived in the Calibration Data Archive System (CDAS), and the HISUI calibration working group plans to assess HISUI radiometric performance and produces radiometric (geometric) calibration databases on CDAS, which are required in Level 1 processing.

The HISUI Hyperspectral Imager is being developed by Japanese Ministry of Economy, Trade, and Industry (METI), which will deploy on International Space Station (ISS) Japan Experiment Module (JEM) in FY2018. The DLR Earth Sensing Imaging Spectrometer (DESIS) is also a hyperspectral instrument developed by the German Aerospace Center (DLR), and Teledyne will integrate DESIS onto its ISS-based imaging platform, the Multi-User System for Earth Sensing (MUSES). This paper shows the cross-calibration and validation for DESIS and HISUI hyperspectral imager.

The Hyperspectral Imager Suite (HISUI) is a future hyper-spectral and multispectral sensor developed by Japanese Ministry of Economy, Trade, and Industry (METI). Radiometric calibration of satellite sensor system is very important for the higher level products with high quality. This paper mainly shows the vicarious calibration and cross-calibration for assessment of HISUI radiometric performance in HISUI Calibration Working Group.

There numerous small-scale public schools, including on remote islands and in other locations, in Kagoshima, Japan. Therefore, we suggest a method of mentoring between young teachers via the Internet because it is difficult for persons to meet in many of these areas. We added three functions to the existing portfolio system and constructed a web communication system that young elementary and junior high school teachers can use for support and to share ideas with each other on the Internet. The teachers used two systems, the comment column and the bulletin board, for different purposes. However, there was considerable variation in the use of the system. Moreover, to improve the use situation, we found that it was necessary to make the system compatible with a mobile phone, making it possible to exchange opinions, and study the applicable scope of communication on the Internet.

Hyperspectral Imager Suite (HISUI) is a Japanese future spaceborne hyperspectral instrument being developed by Ministry of Economy, Trade, and Industry (METI) and will be launched in 2017 or later. In HISUI project, observation strategy is important especially for hyperspectral sensor, and relationship between the limitations of sensor operation and the planned observation scenarios have to be studied. Using observation coverage simulation program and we estimate progress of observation coverage of image with days after launch. We found that HISUI can make 4 times repeated observations for protected area (20 million km2in the world). And about 70 % of land surface can be observed over 5 years. We also found that the developed rules to avoid cloudy are will improve the area coverage up to 2.4 %.

The Hyperspectral Imager Suite (HISUI) is the Japanese next-generation Earth observation project, and is being developed by Japanese Ministry of Economy, Trade, and Industry (METI). We conduct the vicarious calibration for HISUI instrument as the pre-launch activities in summer in the southern hemisphere. Recent our activities focus on vicarious calibration experiment over Lake Lefroy, which is a large salt lake in southern Western Australia. Cross-calibration for HISUI is also discussed. This paper shows both of vicarious calibration and cross-calibration for HISUI instrument.

We have developed a method for radiometric calibration of HISUI's hyper and multi-spectral sensors using a lunar reflectance model developed from SELENE SP data, which involves lunar surface reflectance and photometric properties. For evaluating the utilization of the model, we simulated a lunar observation conducted by ASTER of its three visible and infrared bands and confirmed the model describes lunar surface photometric properties correctly because correlation coefficients of observed and modeled radiance exceed 0.99 for all bands. Although absolute radiance shows some discrepancy between the observed and the simulated Moon in visible band, the model is, at least, useful to evaluate relative degradation of sensors.

Hyperspectral Imager Suite (HISUI) is a future spaceborne hyperspectral and multispectral Earth imaging system being developed by Japanese Ministry of Economy, Trade, and Industry (METI). HISUI project is currently being promoted by three organizations each of which has a contract with METI together with several scientists from universities and national research institutes. The current status of HISUI project will be introduced in the presentation.

As mentioned above, the simulation program is useful to investigate observation-planning strategy and rules for improving efficiency of observations.

The Hyperspectral Imager Suite (HISUI) is the Japanese next-generation Earth observation project, which will be composed of hyperspectral imager (185 spectral bands in VNIR-SWIR region with 30 m spatial resolution) and multispectral imager (4 spectral bands in VNIR region with 5 [m] spatial resolution), and is being developed by Japanese Ministry of Economy, Trade, and Industry (METI) as its third spaceborne optical imager mission after JERS OPS and Terra ASTER. HISUI will provide the earth observation data for global energy and resource issues as well as for other applications such as environmental monitoring and forestry. This paper shows the evaluation of cross calibration with vicarious calibration using EO1 Hyperion, ALI, Landsat7 ETM+, and Terra ASTER with vicarious calibration data.

Hyperspectral Imager Suite (HISUI) is a Japanese future spaceborne hyperspectral instrument [1][2] being developed by Ministry of Economy, Trade, and Industry (METI) and will be launched in 2015 or later. HISUI's operation strategic study is described in this paper. In HISUI project, Operation Mission Planning (OMP) team will make long term and short term strategy of the observation and sensor operation plan. OMP is important for HISUI especially for hyperspectral sensor, and relationship between the limitations of sensor operation and the planned observation scenarios have to be studied. Major factors of the limitations are the combinations of downlink rate, observation time (15 minutes per orbit) and the swath of the sensor (30 km). The achievements of global mapping or repeated observations of specific site need to be simulated precisely before launch [3]. We have prepared daily global high resolution (30 second in latitude and longitude) climate data for the simulation.

The present paper describes the cross calibration of the Remote Sensing Instrument (RSI) onboard Formosat-2 using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) onboard Terra as a reference, which has been continuously calibrated by means of the onboard and vicarious calibration methods. The data integration system for multi-satellite sensor databases on the Global Earth Observation Grid (GEO Grid) is used in order to find pairs of images acquired by both satellite optical sensors over the radiometric calibration sites on the same days. Radiative transfer simulations that consider different imaging conditions using the Second Simulation of a Satellite Signal in the Solar Spectrum (6S) code are performed based on the Moderate-resolution Imaging Spectroradiometer (MODIS) atmosphere and land products, and the optimum methodology for this cross calibration is discussed under the assumption of no ground-based measurements. The derived calibration coefficients are normalized by the values of preflight calibration and are compared with the results of in-flight cross calibration by the Centre National d'Études Spatiales (CNES) and vicarious calibration described in our previous paper. The average degradations of sensor sensitivity since preflight calibration until 2009 are estimated to be 10% (Band2), 11% (Band3), and 8% (Band4). The derived long-term degradation trends are almost consistent with the results of our vicarious calibration within the precision. The cross-calibration methodology used in the present paper facilitates the in-flight radiometric calibration of satellite optical sensors.

The hyperspectral and multispectral remote sensing mission named HISUI is the Japanese next-generation Earth observation project that will be onboard ALOS-3. HISUI will be composed of hyperspectral imager (185 spectral bands in VNIR-SWIR region with 30 m spatial resolution) and multispectral imager (4 spectral bands in VNIR region with 5 m spatial resolution). To expand use of Earth observation data from HISUI, quality assurance and control of data products is indispensable, therefore, the long-term radiometric calibration has a crucial role. The objective of this research is to establish the techniques and develop the plans for conducting the in-flight radiometric calibration of HISUI with high frequency, reliability, and stability, based on the traditional in-flight radiometric calibration for multispectral sensors.

The ASTER on-demand processing service, which provides a Digital Elevation Model (DEM) and orthorectified images was developed and deployed on the GEO Grid system. It is designed to support the latest algorithms for radiometric and atmospheric corrections developed by researchers as well as the geometric correction and other DEM processing options. The functions and options in this service are developed and implemented as modules, so that they can be arranged as the user requires. Although the system is an experimental, it can provide higher quality data sets than the standard products.

We describe the results of the in-orbit radiometric calibration of the remote sensing instrument (RSI) onboard Formosat-2, based on the ground data collected by the advanced spaceborne thermal emission and reflection radiometer (ASTER) calibration team at Ivanpah Playa and Railroad Valley during the regular field campaigns in 2006 and 2008. These results are normalized by the preflight values provided by Astrium, France, and are compared with the results of in-flight calibrations made by Centre National d'Etudes Spatiales, France. The radiometric calibration coefficients and the long-term degrading trend of RSI are derived from the results of vicarious calibration, which estimate that the degradations of sensor sensitivity until 2008 are 2.2% (B4), 8.0% (B3), 9.6% (PAN), 10.3% (B2), and 12.0% (B1). Considering the fact that the ASTER calibration team is able to achieve an accuracy of vicarious calibration better than 5%, we estimate a 7.3% to 13.4% overestimate would be incurred by using the existing in-flight cross calibration coefficients to calculate the spectral radiances. This paper supports the use of vicarious calibration as a reliable approach for the in-orbit radiometric calibration of RSI onboard Formosat-2 on a regular basis.

Surface reflectance products obtained by satellite optical sensors are very important for understanding of earth surface properties. Land researchers often use the multiple satellite sensors' products for validation and scale-up studies. There are various surface reflectance products in each project of satellite sensors. Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) and Moderate Resolution Imaging Spectroradiometer (MODIS) are onboard the same platform, Terra satellite. One MODIS scene includes several ASTER scenes, and it is very useful for cross-calibration, validation, and scale-up studies. On the other hand, we have developed the system on GEO Grid, which can apply the same atmospheric correction algorithm in VNIR for ASTER and MODIS data. This system can generate rayleigh/ozone/water vapor corrected reflectance quickly by using other satellite atmospheric products. This paper shows the evaluation of our in-house products and ASTER/MODIS surface reflectance products (AST07 and MOD09GHK) obtained Railroad Valley in US.

The reflectance-based vicarious calibration approach has been applied to the Advanced spaceborne Thermal emission and reflection radiometer (ASTER) that is on the Terra platform. The results from three separate groups operating at the same sites at the same time are presented. The three groups show good agreement between each other, with differences between the groups being smaller than 4% in all bands ranging from 0.6 to 2.2 mum and with larger differences being seen at shorter wavelengths and beyond 2.2 mum. comparisons between the groups and to the ASTER sensor are best at 1.66 mum (band 4), with differences between each group being less than 0.5% and all of the groups agreeing with ASTER to better than 5%. Differences in the visible and near infrared (VNIR) are larger, particularly prior to August 2002 when an update to the calibration processing was performed. These differences exceed 10% in some bands. In addition, the vicarious results appear to show a different trend than the onboard calibration for the VNIR indicating a possible problem with the onboard calibrator for bands 1-3.

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is a high spatial resolution optical sensor for observing the Earth carried on the National Aeronautics and Space Administration Terra satellite. ASTER consists of three radiometers covering the following regions: visible and near-infrared (VNIR), shortwave infrared (SWIR), and thermal infrared (TIR). The preflight calibration of VNIR and SWIR utilized standard large integrating spheres whose radiance levels were traceable to primary standard fixed-point blackbodies. The onboard calibration devices for the VNIR and SWIR consist of two halogen lamps with photodiode monitors. In orbit, all three bands of the VNIR showed rapid decreases in the output signal while all SWIR bands remained stable. The TIR onboard blackbody was calibrated against a standard blackbody from 100-400 K in a vacuum chamber before launch. The TIR is unable to see the dark space. The temperature of the TIR onboard blackbody remains at 270 K for a short-term calibration to determine any offset and is varied from 270-340 K for a long-term calibration of both the offset and gain. The long-term calibration just after launch was consistent with the prelaunch calibration but then showed a steady decrease of the TIR response over the five years of operation to date.

Describes the preflight and inflight calibration approaches used for the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). The system is a multispectral, high-spatial resolution sensor on the Earth Observing System's EOS-AM1 platform. Preflight calibration of ASTER uses well-characterized sources to provide calibration and preflight round-robin exercises to understand biases between the calibration sources of ASTER and other EOS sensors. These round-robins rely on well-characterized, ultra-stable radiometers. An experiment field in Yokohama, Japan, showed that the output from the source used for the visible and near-infrared (VNIR) subsystem of ASTER may be underestimated by 1.5%, but this is still within the 4% specification for the absolute, radiometric calibration of these bands. Inflight calibration will rely on vicarious techniques and onboard blackbodies and lamps. Vicarious techniques include ground-reference methods using desert and water sites. A recent joint field campaign gives confidence that these methods currently provide absolute calibration to better than 5%, and indications are that uncertainties less than the required 4% should be achievable at launch. The EOS-AM1 platform will also provide a spacecraft maneuver that will allow ASTER to see the Moon, allowing further characterization of the sensor. A method for combining the results of these independent calibration results is presented. The paper also describes the plans for validating the Level 2 data products from ASTER. These plans rely heavily upon field campaigns using methods similar to those used for the ground-reference, vicarious calibration methods.