• 세라미스트
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• 제21권2호
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• pp.59-74
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• 2018

Imaging in the Short Wave Infrared (SWIR) provides several advantages over the visible and near-infrared regions: enhanced image resolution in in foggy or dusty environments, deep tissue penetration, surveillance capabilities with eye-safe lasers, assessment of food quality and safety. Commercially available SWIR imagers are fabricated by integrating expensive epitaxial grown III-V compound semiconductor sensors with Si-based readout integrated circuits(ROIC) by indium bump bonding Infrared image sensors made of solution-processed quantum dots have recently emerged as candidates for next-generation SWIR imagers. They combine ease of processing, tunable optoelectronic properties, facile integration with Si-based ROIC and good performance. Here, we review recent research and development trends of various application fields of SWIR image sensors and nano-materials capable of absorption and emission of SWIR band. With SWIR sensible nano-materials, new type of SWIR image sensor can replace current high price SWIR imagers.

• 한국측량학회지
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• 제39권3호
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• pp.203-209
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• 2021

최근 위성센서 기술의 발전함에 따라 다양한 분광파장대의 고해상도 영상 취득이 가능해졌다. Worldview-3 위성센서는 높은 공간해상도를 지닌 panchromatic 영상과 함께 낮은 공간해상도를 지닌 VNIR (Visible Near InfraRed), SWIR (ShortWave InfraRed) 밴드들을 제공하고 있어, 국방, 환경, 측량 등 다양한 분야에서 활용이 가능하다. 본 연구에서는 Worldview-3 위성영상을 활용하여 광물탐지를 수행하였다. Worldview-3 위성영상의 VNIR, SWIR 밴드들을 효과적으로 활용하기 위해 융합기법을 적용을 통해 panchromatic 영상의 공간해상도로 융합하여 광물탐지에 이용하였다. 광물탐지에 SWIR 밴드들의 활용성을 확인하기 위해 VNIR 밴드들만을 활용한 광물탐지를 수행하여 비교평가하였다. 광물탐지 기법으로는 대표적인 유사도 기법인 SAM (Spectral Angle Mapper)을 적용하였으며, 분석 결과에 경험적 임계치를 적용하여 광물로 탐지되는 화소들을 선정하였다. 광물탐지의 정확도 평가를 위해 유사도 분석을 수행한 결과에 참조자료를 이용하여 정량적평가를 수행하였다. 정확도 평가 결과, SWIR 밴드들을 활용한 광물탐지 결과의 탐지율과 오탐지율이 각각 0.882, 0.011로 계산되었으며, VNIR 밴드들만을 활용한 결과는 각각 0.891, 0.037로 나타났다. SWIR 밴드를 추가적으로 활용한 경우의 탐지율이 VNIR 밴드만을 사용한 경우보다 다소 낮은 것으로 나타났지만, 오탐지율이 크게 감소한 것으로 나타나, 이를 통해 광물탐지에서의 SWIR 밴드들의 활용가능성을 확인할 수 있었다.

• 한국컴퓨터정보학회논문지
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• 제21권11호
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• pp.1-7
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• 2016

In this paper, we proposed real-time relative radiometric calibration processing method for SWIR(Short Wavelength Infra-Red) sensor using 'Hyper-Spectral Imager'. Until now domestic research for Hyper-Spectral Imager has been performing with foreign sensor device. So we have been studying hyper spectral sensor device to meet domestic requirement, especially military purpose. To improve detection & identify capability in 'Hyper-Spectral Imager', it is necessary to expend sensing wavelength from visual and NIR(Near Infra-Red) to SWIR. We aimed to design real-time processor for SWIR sensor which can control the sensor ROIC(Read-Out IC) and process calibrate the image. To build Hyper-Spectral sensor device, we will review the SWIR sensor and its signal processing board. And we will analyze relative radiometric calibration processing method and result. We will explain several SWIR sensors, our target sensor and its control method, steps for acquisition of reference images and processing result.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.760-762
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• 2003

This study confirmed the usefulness of short-wavelength infrared (SWIR) in the discrimination and classification of evergreen forest types. A forested area near Hisayama and Sasaguri in Fukuoka Prefecture, Japan, served as the study area. Warm-temperate forest vegetation dominates the study site vegetation. Coniferous plantation forest, natural broad-leaved forest, and bamboo forest were analyzed using LANDSAT5/TM and SPOT4/HRVIR remote sensing data. Samples were extracted for the three forest types, and reflectance factors were compared for each band. Kappa coefficients of various band combinations were also compared by classification accuracy. For the LANDSAT5/TM data observed in April, October, and November, Bands 5 and 7 showed significant differences between bamboo, broad-leaved, and coniferous forests. The same significant difference was not recognized in the visible or near-infrared regions. Classification accuracy, determined by supervised classification, indicated distinct improvements in band combinations with SWIR, as compared to those without SWIR. Similar results were found for both LANDSAT5/TM and SPOT4/HRVIR data. This study identified obvious advantages in using SWIR data in forest-type discrimination and classification.

• 한국측량학회지
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• 제38권5호
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• pp.435-441
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• 2020

Sentinel-2A satellite imagery provides VNIR (Visible Near InfraRed) and SWIR (ShortWave InfraRed) wavelength bands, and it is known to be effective for land cover classification, cloud detection, and environmental monitoring. Greenhouse is one of the middle classification classes for land cover map provided by the Ministry of Environment of the Republic of Korea. Since greenhouse is a class that has a lot of changes due to natural disasters such as storm and flood damage, there is a limit to updating the greenhouse at a rapid cycle in the land cover map. In the present study, we utilized Sentinel-2A satellite images that provide both VNIR and SWIR bands for the detection of greenhouse. To utilize Sentinel-2A satellite images for the detection of greenhouse, we produced high-resolution SWIR bands applying to the fusion technique performed in two stages and carried out the detection of greenhouse using SVM (Support Vector Machine) supervised classification technique. In order to analyze the applicability of SWIR bands to greenhouse detection, comparative evaluation was performed using the detection results applying only VNIR bands. As a results of quantitative and qualitative evaluation, the result of detection by additionally applying SWIR bands was found to be superior to the result of applying only VNIR bands.

• 대한원격탐사학회지
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• 제39권3호
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• pp.283-295
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• 2023

센서 및 위성 기술의 발전에 따라 전세계적으로 다양한 고해상도 다중대역 위성영상이 활용 가능해지고 있다. 다중대역 센서가 가지는 파장에 기인한 고유한 반사, 투과, 산란 특성에 따라 다중대역 위성영상은 지구 관측에 대한 다양한 상호보완적 지표정보를 제공한다. 특히, short-wave infrared (SWIR) 대역은 긴 파장으로 인해 가시광 대역에 비해 Rayleigh 산란에 적게 영향을 받으며, 이로 인해 특정 대기입자를 투과할 수 있다는 특징을 지닌다. 산불, 폭발 등에 의해 발생된 짙은 연기는 가시광 대역의 영상의 가시성을 저하시키고 일부 지역에 대한 지표를 차폐시키는데, SWIR 대역은 이러한 연기에 의해 가려진 지역에 대한 지표정보를 추가로 제공해주기도 한다. 본 연구에서는 이러한 SWIR 대역과 가시광 대역의 영상 정보를 융합하는 다중해상도 변환 기반의 영상 융합 기법을 제안하였다. 제안된 융합 기법의 목적은 상호보완적 관계에 있는 가시광 대역에서의 고해상도 세부적 배경정보와 SWIR 대역에서의 연기 지역에 대한 지표정보를 모두 내포하고 있는 단일 영상을 생성하는 것이다. 이를 위해 본 연구에서는 라플라시안(Laplacian) 피라미드 기반의 다중해상도 변환 기법을 가시광-SWIR 영상 융합에 적용하였다. 다중해상도 변환 기법은 영상 융합에 널리 활용되는 대표적인 영상분해 기반의 방법론으로, 각각의 원 영상을 다양한 스케일로 분해하여 융합하는 기법이다. 또한, 본 연구는 다중해상도 변환 기법에 haze-guided weight map을 융합한 방법론을 제안하였다. Haze-guided weight map은 SWIR 대역이 연기와 같은 특정 대기입자를 투과하여 지표에 대한 정보를 제공해줄 수 있다는 사전지식에 기반하여 제안된 알고리즘으로 다중해상도로 분해된 두 영상을 융합하는 기준이 되는 가중치 지도로써 활용되었다. 제안된 방법론은 가시광 및 SWIR 대역을 포함하고 있는 고해상도 다중대역 위성영상인 Worldview-3 위성영상을 활용하여 검증되었다. 실험 데이터는 주변 산불로 인해 연기가 발생하여 제한된 가시성을 지닌 연기 지역을 포함하고 있으며, 제안된 방법론의 투과 특성을 검증하기 위해 선정되었다. 제안된 기법에 대한 실험결과는 영상 품질 평가 지표를 활용한 정량평가 및 시각평가를 통해 분석되었으며, 결과분석을 통해 연기 지역에 대한 지표정보를 내포하는 SWIR 대역의 밝은 특징값과 가시광 대역 내의 고해상도 정보가 손실없이 최종 융합 영상에 내포됨을 확인할 수 있었다.

• 한국전기전자재료학회논문지
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• 제37권4호
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• pp.374-381
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• 2024

이 논문은 단파 길이 적외선(SWIR) 영역에서의 활용을 중점적으로 다루며, 실버 황화물(Ag₂S) 나노 구조의 합성과 광학적 특성에 대해 제시한다. SWIR 영역은 생체 조직에 미치는 손상이 감소하고 광학적 투명성이 향상되는 등의 장점을 제공하여 다양한 분야에서 활용되고 있다. 연구는 세 가지 다양한 합성 방법을 소개하며, 각각의 방법을 통해 다양한 광학적 특성을 갖는 나노 입자를 얻을 수 있음을 보여준다. 이러한 연구 결과는 Ag₂S 나노 입자의 크기와 리간드를 조절함으로써 감지, 이미징 및 기타 응용 분야에서의 맞춤형 솔루션을 제공하는 가능성을 열어 놓는다. 이 논문은 SWIR 영역에서 활용 가능한 Ag₂S에 대한 새로운 통찰력을 제공하며, 이를 통해 미래 기술의 발전을 촉진할 것으로 기대된다.

• 한국측량학회지
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• 제36권5호
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• pp.371-379
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• 2018

Unlike general VHR (Very-High-Resolution) satellite sensors that are mainly for panchromatic and MS (Multispectral) imaging, Worldview-3 sensor additionally provides eight SWIR (Short Wavelength Infrared) bands in wavelength range from 1198 nm to 2365 nm. This study investigates the effect of informative Worldview-3 SWIR bands for wetland classification performance. Worldview-3 imagery acquired over Sunchon Bay, which is a coastal wetland located in South Korea, is used to implement the classification. Land-cover classes for the scene are determined by referring to national land-cover maps, which are provided by the Ministry of Environment, overlapped with the scene. After that, training data for each determined class are collected. In order to analyze the effect of SWIR bands, classifications with and without SWIR bands are carried out and the results are then compared. In this regard, a SVM (Support Vector Machine) is utilized as their classifier. As a result of the accuracy assessments performed by test data that are independently extracted from training data, it was confirmed that classification performance was improved when the SWIR bands are included as input features for SVM-based classification.

• 센서학회지
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• 제33권2호
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• pp.93-97
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• 2024

With the development of promising future mobility and urban air mobility (UAM) technologies, the demand for LIDAR sensors has increased. The SWIR photodetector is a sensor that detects lasers for the 3D mapping of lidar sensor and is the most important technology of LIDAR sensor. An SWIR photodetector based on QDs in an eye-safe wavelength band of over 1400 nm has been reported. QDs-based SWIR photodetectors can be synthesized and processed through a solution process and have the advantages of low cost and simple processing. However, the organic ligands of QDs have insulating properties that limit their ability to improve the sensitivity and stability of photodetectors. Therefore, the technology to replace organic ligands with inorganic ligands must be developed. In this study, the organic ligand of the synthesized PbS QDs was replaced with a MAPI inorganic ligand, and an SWIR photodetector was fabricated. The analysis of the characteristics of the manufactured photodetector confirmed that the photodetector based on MAPI-capped PbS QDs exhibited up to 26.5% higher responsivity than that based on organic ligand PbS QDs.

• 센서학회지
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• 제32권5호
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• pp.285-289
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• 2023

Recently, the demand for lidar systems for autonomous driving is increasing, and research on Shortwave Infrared(SWIR) photodetectors for this purpose is being actively conducted. Most SWIR photodetectors currently being developed are based on InGaAs, and have the disadvantages of complex processes, high prices, and limitations in research due to monopoly. In addition, current SWIR photodetectors use lasers in the 905 nm wavelength band, which can pass through the pupil and cause damage to the retina. Therefore, it is required to develop a SWIR photodetector using a wavelength band of 1400 nm or more to be safe for human eyes, and to develop a material that can replace the proprietary InGaAs. PbS QDs are group 4-6 compound semiconductors whose absorption wavelength band can be adjusted from 1000 to 2700 nm, and have the advantage of being simple to process. Therefore, in this study, PbS QDs having an absorption wavelength peak of 1415 nm were synthesized, and a SWIR photodetector was fabricated using this. In addition, the photodetector's responsivity was improved by applying P3HT and ZnO NPs to improve electron hole mobility. As a result of the experiment, it was confirmed that the synthesized PbS QDs had excellent FWHM characteristics compared to commercial PbS QDs, and it was confirmed that the photodetector had a maximum current change of about 1.6 times.