• Korean Journal of Remote Sensing
• /
• v.39 no.6_1
• /
• pp.1491-1495
• /
• 2023

This study utilized automated machine learning (AutoML) to calculate Arctic ice surface temperature (IST). AutoML-derived IST exhibited a strong correlation coefficient (R) of 0.97 and a root mean squared error (RMSE) of 2.51K. Comparative analysis with deep neural network (DNN) models revealed that AutoML IST demonstrated good accuracy, particularly when compared to Moderate Resolution Imaging Spectroradiometer (MODIS) IST and ice mass balance (IMB) buoy IST. These findings underscore the effectiveness of AutoML in enhancing IST estimation accuracy under challenging polar conditions.

• Journal of Korea Water Resources Association
• /
• v.56 no.11
• /
• pp.729-735
• /
• 2023

The Moderate resolution Imaging Spectroradiometer (MODIS) is a multispectral sensor that has been actively researched in various fields using diverse land and atmospheric products. MODIS was first launched over 20 years ago, and the demand for novel sensors that can produce data comparable to that obtained using MODIS has continuously increased. In this study, land products obtained using the Visible Infrared Imaging Radiometer Suite (VIIRS) of the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite launched in 2011 were introduced, including land surface temperature and vegetation indices such as the normalized difference vegetation index and enhanced vegetation index. These land products were compared with existing data obtained using MODIS to verify their local applicability in South Korea. Based on spatiotemporal monitoring of an extreme drought period in South Korea and the application of VIIRS land products, our results indicate that VIIRS can effectively replace MODIS multispectral sensors for agricultural drought monitoring.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.3 no.3
• /
• pp.12-19
• /
• 2000

Knowledge for reflectance characteristic of interesting targets will provide us with actual application of remote sensing on agriculture. In this study, we have measured and analyzed reflectivity characteristics based on growing status from transplanting time to harvesting time. Rice paddies transplant into 3 fields at 20, May, 1999. Measurement of reflectivity characteristics were carried out with a portable spectroradiometer for frequencies from 300nm to 1100nm during the time period from 11:00 AM to 01:00 PM of clear sky and calm a day. The measurements for a day repeated 3 times(also, 3 times to each measurement)for reliable values. In result, we found that averaged reflectivity of visible range has about 2.34% - 2.55% in blue region(400nm-498nm), about 5.05% - 6.01% in green region(500nm-598nm) and about 4.21% - 5.24% in red region(600nm-698nm). It must be noted that the more rice canopy grows, the more spectral reflectivity decreases in visible region. Also, we separated infrared region into two cases - One case is increasing region with 700nm-780nm, the other is fixed region with 800nm-1100nm. Averaged reflectivity of these regions has about 22.3% - 23.0% in increasing region, about 29.4% - 33.1% in fixed region. It must be noted that more rice canopy grows, the more spectral reflectivity also increases up to 23, Aug. in infrared region. After 23, Aug, the reflectivity has a tendency toward decrease.

• Korean Journal of Soil Science and Fertilizer
• /
• v.41 no.2
• /
• pp.126-136
• /
• 2008

Tobacco plants grown in pots by sand culture for 70 days after transplanting were used to evaluate the sensing distance and measurement efficiency of ground-based remote sensors. The leaf distribution of tobacco plant and sensing distance from the sensors to the target leaves were controlled by two removal methods of leaves, top-down and bottom-up removal. In the case of top-down removal, the canopy reflectance was measured by the sensor located at a fixed position having an optimum distance from the detector to the uppermost leaf of tobacco every time that the higher leaves were one at a time. The measurement of bottom-up removal, a the other hand, was conducted in the same manner as that of the top-down removal except that the lower leaves were removed one by one. Canopy reflectance measurements were made with hand held spectral sensors including the active sensors such as $GreenSeeker^{TM}$ red and green, $Crop\;Circle\;ACS-210^{TM}$ red and amber, the passive sensors of $Crop\:Circle^{TM}$, and spectroradiometer $SD2000^{TM}$. The reflectance indices by all sensors were generally affected by the upper canopy condition rather than lower canopy condition of tobacco regardless of sensor type, passive or active. The reflectance measurement by $GreenSeeker^{TM}$ was affected sensitively at measurement distance longer than 120 cm, the upper limit of effective sensing distance, beyond which measurement errors are appreciable. In case of the passive sensors that has no upper limit of effective distance and $Crop\;Circle^{TM}(ACS210)$ that has the upper limit of effective sensing distance specified with 213 cm, longer than that of estimated distance, the measurement efficiency affected by the sensing distance showed no difference. This result suggests that it is necessary to use the sensor specified optimum distance. The result revealed that active sensors are more superior than their passive counterparts in establishing between the relative ratio of reflectance index and the dry weight of tobacco treated by top-down removal, and in the evaluation of biomass. $The\;Crop\;Circle\;ACS-210^{TM}$ red was proved to have the highest efficiency of measurement, followed by $Crop\;Circle^{TM}(ACS210)$ amber and $GreenSeeker^{TM}$ red, $Crop\;Circle^{TM}$ passive, $GreenSeeker^{TM}$ green, and spectroradiometer, in descending order.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2004.04a
• /
• pp.267-273
• /
• 2004

The advantage of the remote sensing is extraction the information of wide area rapidly. Such advantage is the resource and environment are quick and efficient method to grasps accurately method through the land cover classification of wide area. Accordingly this study is used to the high-resolution (6.6m) Electro-Optical Camera (EOC) panchromatic image of the first Korea Multi-Purpose Satellite 1 (KOMPSAT-1) and the multi-spectral Moderate Resolution Imaging Spectroradiometer (MODIS) image data(36 bands).We accomplished FCM classification technique with MLC technique to be general land cover classification method in the content of research. And evaluated the accuracy assessment of two classification method.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2004.04a
• /
• pp.251-257
• /
• 2004

The Electro-Optical Camera(EOC) image of the first Korea Multi-Purpose Satellitel(KOMPSAT-1) has both high resolution and convenient acquisition of research data, but on the other hand it has a defect of one band image. Fortunately, the multispectral Moderate Resolution Imaging Spectroradiometer (MODIS) image data are receiving every day at the Korea Aerospace Research Institute (KARI). Therefore, this paper performed an effective merging for survey of reclaimed land using the high-resolution (6.6m) KOMPSAT-1 EOC image and the multispectral MODIS image data. According this paper prepared map of reclaimed lands in Western Coast of North Korea as quantitative(position and form) survey of reclaimed lands of North Korea using merged image. The use of KOPSAT-1 EOC image and MODIS images was found to be economical such using of large scale areas as reclaimed land or according easy to collect information and such north korea as inaccessible areas like as receiving every day.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.19 no.5
• /
• pp.29-45
• /
• 2016

This study identified vulnerable regions in the national parks of the Republic of Korea (ROK). The potential vulnerable regions were defined as areas showing a decline in forest productivity, low resilience, and high sensitivity to climate variations. Those regions were analyzed with a regression model and trend analysis using the Enhanced Vegetation Index (EVI) data obtained from long-term observed Moderate Resolution Imaging Spectroradiometer (MODIS) and gridded meteorological data. Results showed the area with the highest vulnerability was Naejangsan National Park in the southern part of ROK where 32.5% ($26.0km^2$) of the total area was vulnerable. This result will be useful information for future conservation planning of forest ecosystem in ROK under environmental changes, especially climate change.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1993.10a
• /
• pp.383-392
• /
• 1993

Identification of rice paddy fields and estimation of their areas from the images taken by LANDSAT-5/TM were attempted. The results were verified by aerial photographs and also by ground observations. Changes of the spectral characteristics of rice plants were measured with a portable spectroradiometer during the growth period. Analyzing these characteristics, an index was developed for evaluating the growth and the yield of rice . Applying the index to the data observed by LANDSAT-5.TM on Sep. 26, 1986, Oct .20, 1989 and Sep, 21, 1990, it was confirmed that the estimated derived from the index agreed with actual values. The results well demonstrated its feasibility for evaluating the yield of rice by a satellite like LANDSAT-5/TM.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2001.10a
• /
• pp.505-508
• /
• 2001

Remote Sensing is one of effective methods for collecting, analyzing information and predicting the change of agricultural environments. The RS technique is based on the principle that the object reflects a peculiar radio wave according to types and environmental conditions. For collection RS base data, used spectroradiometer which measures reflection characteristics between $300{\sim}1,100nm$ and measured the reflection of Mi-ho stream's water resources which is located thong-won, Chung-buk province, Korea. The difference of reflectance represents the characteristic of bottom soil, water color and matters in water.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2001.10a
• /
• pp.513-516
• /
• 2001

Water stress measurements of rice that use spectral reflection characteristics have been conducted to detect a water stress of rice during growing stage. Water stress reaction was measured using a spectroradiometer in the wavelength range from 300nm to 1100nm. In order to maintain all the experimental conditions, the measurement time have been settled at a fixed solar radiation times. Spectral reflectance were measured as a function of the moisture content. The results indicate that the spectral reflectance of rice was dependent on moisture content. As the moisture content is lowered the spectral reflectance of rice formed in NIR wavelength range increased. This effect can be best explained in terms of water stress.