• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.214-218
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• 1999

The aim of our study is to develop new algorism for sea fog detection by using Geostational Meteorological Satellite-5(GMS-5) and suggest the techniques of its continuous detection. So as to detect daytime sea fog/stratus(00UTC, May 10, 1999), visible accumulated histogram method and surface albedo method are used. The characteristic value during daytime showed A(min) > 20％ and DA < 10％ when visble accumulated histogram method was applied. And the sea fog region which detected is of similarity in composite image and surface albedo method. In case of nighttime sea fog(18UTC, May 10, 1999), infrared accumulated histogram method and maximum brightness temperature method are used, respectively. Maximum brightness temperature method(T_max method) detected sea fog better than IR accumulated histogram method. In case of T_max method, when infrared value is larger than T_max, fog is detected, where T_max is an unique value, maximum infrared value in each pixel during one month. Then T_max is beneath 700hpa temperature of GDAPS(Global Data Assimilation and Prediction System). Sea fog region which detected by T_max method was similar to the result of National Oceanic and Atmosheric Administration/Advanced Very High Resolution Radiometer (NOAA/AVHRR) DCD(Dual Channel Difference). But inland visibility and relative humidity didn't always agreed well.

• 한국군사과학기술학회지
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• 제21권6호
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• pp.744-751
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• 2018

In this paper, we propose a fast detection and identification algorithm of chemical gases with a passive FTIR spectrometer. We use a pre-detection algorithm that can reduce the spatial region effectively for gas detection and the candidates of the target. It is possible to remove background spectra effectively from measured spectra with the least-squares method. The CC(Correlation Coefficients) and the SNR(Signal-to-Noise Ratio) methods are used for the detection of target gases. The proposed pre-detection algorithm allows the total process of chemical gas detection to be performed with lower complexity compared with the conventional algorithms. This paper can help developing real-time chemical detection instruments and various applications of FTIR spectrometers.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.654-655
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• 2003

Korea has experienced 10 a Cochlodinium polykrikoides red tide outbreaks during the last 10 years (1993-2002). The monitoring activities at National Fisheries Research and Development Institute (NFRDI) in Korea have been extended to all the coastal waters after the worst of fish killing by C. polykrikoides blooms in 1995. NFRDI is looking forward to finding out the feasibility of red tide detection around Korean waters using satellite remote sensing of NOAA/AVHRR, Orbview-2/SeaWiFS, IRS-P4/OCM and Terra/MODIS on real time base. In this study, we used several alternative methods including climatological analysis, spectral and optical methods which may offer a potential detection of the major species of red tide in Korean waters. The relationship between the distribution of SST and C. polykrikoides bloom areas was studied. In climatological analysis, NOAA, SeaWiFS, OCM satellite data in 20th and 26th August 2001 were chosen using the known C. polykrikoides red tide bloom area mapped by helicopter reconnaissance and ground observation. The 26th August, 2001 SeaWiFS chlorophyll a anomaly imageries against the imageries of non-occurring red tide for August 20, 2001 showed the areas C. polykrikoides occurred. The anomalies of chlorophyll a concentration from satellite data between before and after red tide outbreaks showed the similar distribution of C. polykrikoides red tide in 26th August, 2001. The distribution of the difference in SST between daytime and nighttime also showed the possibility of red tide detection. We used corrected vegetation index (CVI) to detect floating vegetation and submerged vegetation containing algal blooms. The simple result of optical absorption from C. polykrikoides showed that if we use the optical characteristics of each red tide we will be able to get the feasibility of the red tide detection.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.702-705
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• 2006

Change detection is a core function of remote sensing. It can be widely used in public services such as land monitoring, damage assessment from disaster, analysis of city growth, etc. However, it seems that the change detection using satellite imagery has not been fully used in public services. For the person who is in charge of public services, it seems not to be ease to implement the change detection because various functions are combined into it. So, to promote the use of the change detection in public services, the standard, the process and the method for the change detection in public services should be established. And the software which supports that will be very useful. This study aims to promote the use of satellite imagery in public services by building up the change detection process which are suitable for general public services and developing the change detection software to support the process. The software has been developed using ETRI Components for Satellite Image Processing to support the interoperability with other GIS software.

• Journal of electromagnetic engineering and science
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• 제12권4호
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• pp.234-239
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• 2012

This paper presents a compact K-band Doppler radar sensor for human vital signal detection that uses a radar configuration with only single coupler. The proposed radar front-end configuration can reduce the chip size and the additional RF power loss. The radar front-end IC is composed of a Lange coupler, VCO, and single balanced mixer. The oscillation frequency of the VCO is from 27.3 to 27.8 GHz. The phase noise of the VCO is -91.2 dBc/Hz at a 1 MHz offset frequency, and the output power is -4.8 dBm. The conversion gain of the mixer is about 11 dB. The chip size is $0.89{\times}1.47mm^2$. The compact Ka-band Doppler radar system was developed in order to demonstrate remote human vital signal detection. The radar system consists of a Ka-band Doppler radar module with a $2{\times}2$ patch array antenna, baseband signal conditioning block, DAQ system, and signal processing program. The front-end module size is $2.5{\times}2.5cm^2$. The proposed radar sensor can properly capture a human heartbeat and respiration rate at the distance of 50 cm.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.253-256
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• 2005

The use of satellite remote sensing in maritime safety and security can aid in the detection of illegal fishing activities and provide more efficient use of limited aircraft or patrol craft resources. In the area of vessel traffic monitoring for commercial vessels, Vessel Traffic Service (VTS) which use the ground-based radar system have some difficulties in detecting moving ships due to the limited detection range. A virtual vessel traffic control system is introduced to contribute to prevent a marine accident such as collision and stranding from happening. Existing VTS has its limit. The virtual vessel traffic control system consists of both data acquisition by satellite remote sensing and a simulation of traffic environment stress based on the satellite data, remotely sensed data. And it could be used to provide timely and detailed information about the marine safety, including the location, speed and direction of ships, and help us operate vessels safely and efficiently. If environmental stress values are simulated for the ship information derived from satellite data, proper actions can be taken to prevent accidents. Since optical sensor has a high spatial resolution, JERS satellite data are used to track ships and extract their information. We present an algorithm of automatic identification of ship size and velocity. This paper lastly introduce the field testing results of ship detection by RADARSAT SAR imagery, and propose a new approach for a Vessel Monitoring System(VMS), including VTS, and SAR combination service.

• 대한원격탐사학회지
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• 제24권5호
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• pp.445-452
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• 2008

Preliminary results are reported on ship detection using coherence images computed from cross-correlating images of multi-look-processed dual-polarization data (HH and HV) of ENVISAT ASAR. The traditional techniques of ship detection by radars such as CFAR (Constant False Alarm Rate) rely on the amplitude data, and therefore the detection tends to become difficult when the amplitudes of ships images are at similar level as the mean amplitude of surrounding sea clutter. The proposed method utilizes the property that the multi-look images of ships are correlated with each other. Because the inter-look images of sea surface are covered by uncorrelated speckle, cross-correlation of multi-look images yields the different degrees of coherence between the images and water. In this paper, the polarimetric information of ships, land and intertidal zone are first compared based on the cross-correlation between HH and HV images, In the next step, we examine the technique when the dual-polarization data are split into two multi-look images, It was shown that the inter-look cross-correlation method could be applicable in the performance improvement of small ship detection and the land masking, It was also found that a simple combination of coherence images from each co-polarised (HH) inter-look and cross-polarised (HV) inter-look data can provide much higher target-detection possibilities.

• 정보과학회 논문지
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• 제45권2호
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• pp.106-112
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• 2018

최근 악성코드를 이용한 사이버 공격이 급증하고 있다. 피해가 늘어남에 따라 수 년간 다양한 방식의 악성코드 탐지 기법들이 연구되고 있으며, 최근 공격 그룹 판별을 위한 다양한 프로파일링 등장하고 있다. 본 논문은 악성코드 탐지가 아닌 특정 악성코드를 사용하는 공격 그룹에 대한 판별을 주목적으로 하며, 판별에 각 공격 그룹이 사용하는 악성코드에 대한 문자열 및 코드 시그니처를 이용한다. 탐지 기법을 구현하기 위해 야라(Yara)를 사용하였으며, 공격 그룹에서 주로 사용되는 원격 관리 도구(RAT, Remote Access Tool)를 대상으로 연구를 진행했다. 또한 탐지율 증가를 위하여 악성코드 패킹 여부 확인 및 해제 기술을 추가하였다. 본 논문은 최근 공격 그룹들이 주로 사용하는 원격 관리 도구를 대상으로 악성코드와 패커의 주요 특징 시그니처를 이용해 룰셋(Ruleset)을 작성하고 작성한 룰셋을 기반으로 원격관리 도구 탐지 및 공격 그룹 판별 가능성에 대해 다룬다.

• 대한원격탐사학회지
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• 제38권5_1호
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• pp.559-570
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• 2022

광학 위성 영상의 공간해상도가 낮게 되면 크기가 작은 객체들의 경우 객체 탐지의 어려움이 따른다. 따라서 본 연구에서는 위성 영상의 공간해상도를 향상시키는 초해상화(Super-resolution) 기술이 객체 탐지 정확도 향상에 대한 영향이 유의미한지 알아보고자 하였다. 쌍을 이루지 않는(unpaired) 초해상화 알고리즘을 이용하여 Sentinel-2 영상의 공간해상도를 3.2 m로 향상시켰으며, 객체 탐지 모델인 Faster-RCNN, RetinaNet, FCOS, S²ANet을 활용하여 초해상화 적용 유무에 따른 선박 탐지 정확도 변화를 확인했다. 그 결과 선박 탐지 모델의 성능 평가에서 초해상화가 적용된 영상으로 학습된 선박 탐지 모델들에서 Average Precision (AP)가 최소 12.3%, 최대 33.3% 향상됨을 확인하였고, 초해상화가 적용되지 않은 모델에 비해 미탐지 및 과탐지가 줄어듦을 보였다. 이는 초해상화 기술이 객체 탐지에서 중요한 전처리 단계가 될 수 있다는 것을 의미하고, 객체 탐지와 더불어 영상 기반의 다른 딥러닝 기술의 정확도 향상에도 크게 기여할 수 있을 것으로 기대된다.

• 방송공학회논문지
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• 제28권1호
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• pp.124-131
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• 2023

원거리에서 특정 영역의 물리적 특성 또는 상황에 대한 정보를 얻기 위해 원격 탐사 영상에 객체 검출 기법이 연구되고 있다. 이때 저해상도인 원격 영상은 정보의 손실로 인해 객체 검출의 정확도가 떨어지는 문제가 발생한다. 본 논문에서는 이러한 문제점을 해결하기 위해 초고해상도 기법과 객체 검출 방법을 하나의 네트워크로 구성하여 원격 영상에서 객체 검출의 성능을 높이는 방법을 제안한다. 제안한 방법은 심층 잔차 밀집 기반의 네트워크를 구성하여 저해상도 영상에서 객체의 특징을 복원하고자 하였다. 추가적으로 이를 객체 검출 단계인 YOLOv5와 하나의 네트워크로 구성함으로써 객체 검출의 성능을 향상시키고자 하였다. 제안한 방법은 저해상도 영상을 위해 VEDAI 데이터를 이용하였으며 차량 검출에서 VISIBLE 기준으로 mAP@0.5에 대해 81.38%까지 향상됨을 확인하였다.