Evaluation of GSICS Correction for COMS/MI Visible Channel Using S-NPP/VIIRS
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- Korean Journal of Remote Sensing
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- v.37 no.1
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- pp.169-176
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- 2021
The Global Space-based Inter-Calibration System (GSICS) is an international partnership sponsored by World Meteorological Organization (WMO) to continue and improve climate monitoring and to ensure consistent accuracy between observation data from meteorological satellites operating around the world. The objective for GSICS is to inter-calibration from pairs of satellites observations, which includes direct comparison of collocated Geostationary Earth Orbit (GEO)-Low Earth Orbit (LEO) observations. One of the GSICS inter-calibration methods, the Ray-matching technique, is a surrogate approach that uses matched, co-angled and co-located pixels to transfer the calibration from a well calibrated satellite sensor to another sensor. In Korea, the first GEO satellite, Communication Ocean and Meteorological Satellite (COMS), is used to participate in the GSICS program. The National Meteorological Satellite Center (NMSC), which operated COMS/MI, calculated the Radiative Transfer Model (RTM)-based GSICS coefficient coefficients. The L1P reproduced through GSICS correction coefficient showed lower RMSE and Bias than L1B without GSICS correction coefficient applied. The calculation cycles of the GSICS correction coefficients for COMS/MI visible channel are provided annual and diurnal (2, 5, 10, 14-day), but long-term evaluation according to these cycles was not performed. The purpose of this paper is to perform evaluation depending on the annual/diurnal cycles of COMS/MI GSICS correction coefficients based on the ray-matching technique using Suomi-NPP/Visible Infrared Imaging Radiometer Suite (VIIRS) data as reference data. As a result of evaluation, the diurnal cycle had a higher coincidence rate with the reference data than the annual cycle, and the 14-day diurnal cycle was the most suitable for use as the GSICS correction coefficient.
Objective : The purpose of this study was to investigate difference in fascicle behavior of the medial gastrocnemius during the locomotion with varying intensities, such as gait and one-legged and two-legged vertical jumping. Methods : Six subjects (3 males and 3 females; age:
한국천문연구원은 과학기술위성 3호의 주탑재체인 다목적 적외선영상시스템(Multipurpose Infra-Red Imaging System, MIRIS)을 개발하고 있다. 이 연구개발 사업은 2007년 교육과학기술부의 과학위성 3호 사업 주탑재체 공모를 통하여 10여개의 후보 탑재체 제안서 중에서 최종적으로 채택되었고, 2011년 발사를 목표로, 3년 동안의 연구개발 기간을 거쳐 현재 비행모델 (FM, Flight Model) 개발이 진행 중이다. MIRIS는 한국천문연구원이 개발하여 2003년 발사에 성공한 과학위성 1호 주탑재체인 원자외선 영상분광기 (FIMS, Far ultra-violet IMaging Spectroscope)에 이어 국내에서 자체 개발되는 두 번째 우주망원경이다. MIRIS는 우주공간에서 0.9~2 micron 사이 적외선 영역의 파쉔 알파 방출선 (Paschen Alpha Emiision Line)과 광대역 I, H 파장영역을 관측할 예정이다. 주요 과학임무로는 아직까지 국제 천문학계에서 잘 알려지지 않은 우리은하 내부에 분포한 고온 플라즈마 (Warm Ionized Medium, WIM)의 기원 연구와 아울러 우리은하 성간난류(Interstellar Turbulence)의 특성 및 적외선 우주배경복사의 (Cosmic Infrared Background; CIB) 거대구조 등을 관측연구할 예정이다. 특히 MIRIS는 저온상태 (절대온도 77K, 약
An algorithm was developed to retrieve both cloud optical thickness and effective particle radius considered the aerosol effect on clouds. This study apply the algorithm of Nakajima and Nakajima (1995) that is used to retrieve cloud optical thickness and effective particle radius from visible, near infrared satellite spectral measurements. To retrieve cloud properties, Look-up table (LUT) was made under different atmospheric conditions by using a radiative transfer model. Especially the vertical distribution of aerosol is based on a tropospheric aerosol profile in radiative transfer model. In the case study, we selected the extensive forest fire occurred in Russia in May 2003. The aerosol released from this fire may be transported to Korea. Cloud properties obtained from these distinct atmospheric situations are analysed in terms of their possible changes due to the interactions of the clouds with the aerosol particle plumes. Cloud properties over the East sea at this time was retrieved using new algorithm. The algorithm is applied to measurements from the MODerate Resolution Imaging Spectrometer (MODIS) onboard the Terra spacecrafts. As a result, cloud effective particle radius was decreased and cloud optical thickness was increased during aerosol event. Specially, cloud effective particle radius is hardly greater than
Global warming causes climate change and increases extreme weather events worldwide, and the occurrence of heatwaves and droughts is also increasing in Korea. For the monitoring of extreme weather, various satellite data such as LST (Land Surface Temperature), TCI (Temperature Condition Index), NDVI (Normalized Difference Vegetation Index), VCI (Vegetation Condition Index), and VHI (Vegetation Health Index) have been used. VHI, the combination of TCI and VCI, represents the vegetation stress affected by meteorological factors like precipitation and temperature and is frequently used to assess droughts under climate change. TCI and VCI require historical reference values for the LST and NDVI for each date and location. So, it is complicated to produce the VHI from the recent satellite GK2A (Geostationary Korea Multi-Purpose Satellite-2A). This study examined the retrieval of VHI using GK2A AMI (Advanced Meteorological Imager) by referencing the historical data from VIIRS (Visible Infrared Imaging Radiometer Suite) NDVI and LST as a proxy data. We found a close relationship between GK2A and VIIRS data needed for the retrieval of VHI. We produced the TCI, VCI, and VHI for GK2A during 2020-2021 at intervals of 8 days and carried out the interpretations of recent extreme weather events in Korea. GK2A VHI could express the changes in vegetation stress in 2020 due to various extreme weather events such as heatwaves (in March and June) and low temperatures (in April and July), and heavy rainfall (in August), while NOAA (National Oceanic and Atmospheric Administration) VHI could not well represent such characteristics. The GK2A VHI presented in this study can be utilized to monitor the vegetation stress due to heatwaves and droughts if the historical reference values of LST and NDVI can be adjusted in a more statistically significant way in the future work.
Objectives : This study aims to evaluate the effectiveness and safety of Korean medicine for a thoracolumbar compression fracture. Methods : We searched six Korean databases (DBPIA, Korean Studies Information Service System, Oriental Medicine Advanced Searching Integrated System, National Digital Science Library, Research Information Sharing Service, KoreaMed) (up to June 2015) and the Journal of Korean Acupuncture and Moxibustion Society. Unpublished studies were also searched. Clinical research, other than case reports involving less than 10 patients, were eligible. The effectiveness and safety of Korean Medicine was analyzed. The 'Risk of Bias' was assessed using the 'Risk of Bias' assessment tool for non-randomized studies as well as the Cochrane Collaboration's 'Risk of Bias' tool. Results : We found 12 before-after studies (374 patients). There was no randomized trial. All studies combined at least three different types of Korean medicine treatments. The period of treatment varied between less a week and 154 days. All the included studies reported improvements in pain, functional disability related to lower back pain, global assessment, and benefits in the compression ratio of a fractured vertebrae and skin temperature measured by digital infrared thermal imaging in comparison with the baseline. However, all studies had a high risk of bias and three studies reported mild adverse events. Conclusions : There is no randomized trial for the role of Korean medicine for patients with a thoracolumbar compression fracture. The effectiveness and safety of Korean medicine for this population remains unclear. Findings in this review are seriously biased due to observational design and a high risk of bias included in the studies. Future high-quality randomized trials are warranted.
Recently, heart rate signal, which is one of biological signals, have been used in various fields related to healthcare. Conventionally, most of the proposed heart rate signal detection methods are contact type methods, but there is a problem of discomfort that the subject have to contact with the device. In order to solve the problem, detection study by non-contact method has been progressed recently. The detected heart rate signal can be used for finger vein liveness detection and various application using heart rate. In this paper, we propose a method to obtain heart rate signal by using finger vein imaging system. The proposed method detected the signal from the changes of the brightness value in the time domain of the infrared finger vein images and converted it into the frequency domain using the image processing algorithm. After the conversion, we removed the noise not related to the heart rate signal through band-pass filtering. In order to evaluate the accuracy of the signal, we analyzed the correlation with the signal obtained simultaneously with the finger vein acquisition device and contact type PPG sensor approved by KFDA. As a result, it was possible to confirm that the heart rate signal detected in non-contact method through the finger vein image coincides with the waveform of actual heart rate signal.
We investigated the relative errors of satellite-observed Surface Skin Temperature (SST) data caused by sea ice in the northern hemispheric ocean (
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70