scholarly journals METODE DUAL KANAL UNTUK ESTIMASI KEDALAMAN DI PERAIRAN DANGKAL MENGGUNAKAN DATA SPOT 6 STUDI KASUS : TELUK LAMPUNG (DUAL BAND METHOD FOR BATHYMETRY ESTIMATION IN SHALLOW WATERS DEPTH USING SPOT 6 DATA CASE STUDY: LAMPUNG BAY)

2017 ◽  
Vol 14 (1) ◽  
Author(s):  
Muchlisin Arief ◽  
Syifa Wismayati Adawiah ◽  
Ety Parwati ◽  
Sartono Marpaung
Keyword(s):  
Correlation Function ◽  
Linear Equations ◽  
Depth Estimation ◽  
Efficient Estimation ◽  
Dual Band ◽  
Sensing Technology ◽  
Band Method ◽  
Rms Error ◽  
The Difference ◽  
Dark Pixel

Depth data can be used to produce seabed profile, oceanography, biology, and sea level rise. Remote sensing technology can be used to estimate the depth of shallow marine waters characterized by the ability of light to penetrate water bodies. One image that can estimate the depth is SPOT 6 which has three visible canals and one NIR channel with 6 meter spatial resolution. This study used SPOT 6 image on March 22, 2015. The image was first being  dark pixel atmospheric corrected by making 30 polygons. The originality of this method was to build a correlation between the dark pixel value of red and green channels with the depth of the field measurement results, made on June 3 to 9, 2015. The algorithm  derived experimentally consisted of: thresholding which served to separate the land by the sea and the correlation function. The correlation function was obtained: first correlating the observation value with each band, then calculating the difference of minimum pixel darkness value and minimum for red and green channel was 0.056 and 0.0692. The model was then constructed by using the comparison proportions, so that the linear equations were obtained in two channels: Z (X1, X2) = 406.26 X1 + 327.21 X2 - 28.48. Depth estimation results were for a 5-meter scale, the most efficient estimation with the smallest error relative mean occured in shallow water depth from 20 to 25 meters, while the result of   10 meters scale from 20 to 30 meters and the estimated depth hadsimilar patterns or could be said close to reality. This method was able to detect sea depths up to 25 meters and had a small RMS error of 0.653246 meters. Thus the two-channel method coukd offer a fast, flexible, efficient, and economical solution to map topography of the ocean floor.AbstrakData kedalaman dapat digunakan untuk menghasilkan profil dasar laut, oseanografi, biologi, dan kenaikan muka air laut. Teknologi penginderaan jauh dapat digunakan untuk mengestimasi kedalaman perairan laut dangkal yang ditandai dengan kemampuan cahaya untuk menembus badan air. Salah satu citra yang mampu mengestimasi kedalaman tersebut adalah SPOT 6 yang memiliki tiga kanal visible dan satu kanal NIR dengan resolusi spasial 6 meter. Pada penelitian ini, Citra SPOT-6 yang digunakan adalah 22 Maret 2015. Citra terlebih dahulu dilakukan koreksi atmosferik dark pixel dengan membuat 30 poligon. Originalitas dari metode ini adalah membangun suatu korelasi antara nilai dark pixel kanal merah dan hijau dengan nilai kedalaman hasil pengukuran lapangan yang dilakukan pada 3 sampai dengan 9 Juni 2015. Algoritma diturunkan secara eksperimen yang terdiri dari thresholding yang berfungsi untuk memisahkan daratan dengan lautan dan fungsi korelasi. Fungsi korelasi diperoleh pertama-tama mengkorelasikan nilai pengamatan dengan masing-masing band, kemudian menghitung selisih nilai dark pixel maksimum dan minimum untuk kanal merah dan hijau yaitu 0,056 dan 0,0692. Selanjutnya, dibangun model dengan menggunakan dalil perbandingan sehingga diperoleh persamaan linier dalam dua kanal yaitu: Z(X1,X2) = 406,26 X1 + 327,21 X2 – 28,48. Hasil estimasi kedalaman, untuk skala 5 meter, estimasi yang paling efisien dengan Mean relatif error terkecil terjadi pada kedalaman perairan dangkal dari 20 sampai dengan 25 meter, sedangkan untuk skala 10 meter dari 20 sampai dengan 30 meter dan juga hasil estimasi kedalaman yang diperoleh mempunyai pola kemiripan atau dapat dikatakan mendekati kenyataan. Metode ini mampu mendeteksi kedalaman laut hingga 25 meter dan mempunyai RMS error yang kecil yaitu 0,653246 meter. Dengan demikian, metode dua kanal ini dapat menawarkan solusi cepat, fleksibel, efisien, dan ekonomis untuk memetakan topografi dasar laut.

Statistical energy analysis as a tool for quantifying sound and vibration transmission paths

1994 ◽  
Vol 346 (1681) ◽  
pp. 449-464 ◽  
Keyword(s):  
Energy Flow ◽  
Complex Structure ◽  
Linear Equations ◽  
Least Square ◽  
Net Energy ◽  
Sea Temperature ◽  
Energy Flows ◽  
The Difference ◽  
Symmetry Relations ◽  
Loss Factors

When a complex structure is excited in several different ways by different sources, the sea energy balance equations result in a set of linear equations that can be used to calculate loss factors, coupling loss factors or net energy flows and incoming powers. If certain symmetry relations are used, and/or if some prior knowledge about the system is available, the set of linear equations is overdetermined and can be solved by a least square technique. A good indicator for the direction of the energy flow is the SEA temperature of the subsystems. Experiments and computer simulations performed on three plate arrangements gave in general good results when the coupling was weak and there were more than three modes in the frequency band of interest. Not so good results were obtained when a small energy flow has to be measured as the difference of large quantities.

scholarly journals Vegetation Height Estimation using Satellite Remote Sensing in Peat Land of Central Kalimantan

2021 ◽  
Vol 6 (1) ◽  
pp. 024-034
Author(s):  
Atriyon Julzarika ◽  
Harintaka Harintaka ◽  
Tatik Kartika
Keyword(s):  
Remote Sensing ◽  
Spatial Information ◽  
Geoid Undulation ◽  
Height Estimation ◽  
Central Kalimantan ◽  
Vegetation Height ◽  
Accuracy Test ◽  
Sensing Technology ◽  
The Difference ◽  
Difference Test

Vegetation height is an important parameter in monitoring peatlands. Vegetation height can be estimated using remote sensing. Vegetation height can be estimated by utilizing DSM and DTM. The data that can be used are LiDAR, X-SAR, and SRTM C. In this study, LiDAR data is used for DSM2018 and DTM2018 extraction. The purpose of this research is to detect the vegetation height in Central Kalimantan peatlands using remote sensing technology. The research location is in Bakengbongkei, Kalampangan, Central Kalimantan. The integration of X-SAR and SRTM C is used for DSM2000 and DTM2000 extraction. DSM2000, DTM2000, DSM2018, and DTM2018 performed height error correction with tolerance of 1.96? (95%). Then do the geoid undulation correction to EGM2008. The results obtained are DSM and DTM with a similar height reference field. If it meets these conditions it can be calculated the vegetation height estimation. Vegetation height can be obtained using the Differential DEM method. The Changing in vegetation height from 2000 to 2018 can be estimated from the difference in vegetation height from 2000 to vegetation height in 2018. Results of spatial information on vegetation height and its changes need to be tested for the accuracy. This accuracy-test includes a cross section test, height difference test, and comparison with measurements of vegetation height in the field. The results of this research can be used to monitor the changing the vegetation height in peatlands.

scholarly journals Design of Two Novel Dual Band-Notched UWB Antennas

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Bing Li ◽  
Jing-song Hong
Keyword(s):  
Time Domain ◽  
Simple Structure ◽  
The Other ◽  
Ultra Wideband ◽  
Dual Band ◽  
Uwb Antennas ◽  
Monopole Antennas ◽  
Printed Monopole ◽  
The Difference ◽  
The Time Domain

Two novel dual band-notched ultra-wideband (UWB) printed monopole antennas with simple structure and small size are presented. The size of both antennas is25×25×0.8 mm3. The bandwidth of one of the proposed antenna can be from 2.7 GHz to 36.8 GHz, except the bandwidth of 3.2–3.9 GHz for WiMAX applications and 5.14–5.94 GHz for WLAN applications. The bandwidth of the other is ranging for 2.7 to 41.1 GHz, except the bandwidth of 3.2–3.9 GHz for WiMAX applications and 4.8–5.9 GHz for WLAN applications. Bandwidths of the antennas are about 512% and 455% wider than those of conventional band-notched UWB antennas, respectively. In addition, the time-domain characteristics of the two antennas are investigated to show the difference between both antennas.

scholarly journals Model for the growth of the world airline network

2016 ◽  
Vol 27 (12) ◽  
pp. 1650141 ◽  
Author(s):  
T. Verma ◽  
N. A. M. Araújo ◽  
J. Nagler ◽  
J. S. Andrade ◽  
H. J. Herrmann
Keyword(s):  
Correlation Function ◽  
Growth Model ◽  
Physical Distance ◽  
Transport Networks ◽  
Model Network ◽  
The World ◽  
Airline Networks ◽  
Airline Network ◽  
The Difference

We propose a probabilistic growth model for transport networks which employs a balance between popularity of nodes and the physical distance between nodes. By comparing the degree of each node in the model network and the World Airline Network (WAN), we observe that the difference between the two is minimized for [Formula: see text]. Interestingly, this is the value obtained for the node–node correlation function in the WAN. This suggests that our model explains quite well the growth of airline networks.

scholarly journals Gradient Correlation Functions in Digital Image Correlation

2019 ◽  
Vol 9 (10) ◽  
pp. 2127 ◽  
Author(s):  
Mikael Sjödahl
Keyword(s):  
Correlation Function ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Correlation Functions ◽  
Laser Speckle ◽  
Image Correlation ◽  
Intensity Correlation ◽  
Intensity Correlation Function ◽  
Speckle Patterns ◽  
The Difference

The performance of seven different correlation functions applied in Digital Image Correlation has been investigated using simulated and experimentally acquired laser speckle patterns. The correlation functions were constructed as combinations of the pure intensity correlation function, the gradient correlation function and the Hessian correlation function, respectively. It was found that the correlation function that was constructed as the product of all three pure correlation functions performed best for the small speckle sizes and large correlation values, respectively. The difference between the different functions disappeared as the speckle size increased and the correlation value dropped. On average, the random error of the combined correlation function was half that of the traditional intensity correlation function within the optimum region.

scholarly journals Estimation of relative source locations from seismic amplitude: application to earthquakes and tremors at Meakandake volcano, eastern Hokkaido, Japan

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Masashi Ogiso ◽  
Kiyoshi Yomogida
Keyword(s):  
Amplitude Ratio ◽  
Linear Equations ◽  
Site Amplification ◽  
New Method ◽  
Seismic Events ◽  
Arrival Times ◽  
Event Location ◽  
Tectonic Earthquakes ◽  
The Difference ◽  
Seismic Amplitudes

AbstractAlthough seismic amplitudes can be used to estimate event locations for volcanic tremors and other seismic events with unclear phase arrival times, the precision of such estimates is strongly affected by site amplification factors. Therefore, reduction of the influence of site amplification will allow more precise estimation of event locations by this method. Here, we propose a new method to estimate relative event locations using seismic amplitudes. We use the amplitude ratio between two seismic events at a given station to cancel out the effect of the site amplification factor at that station. By assuming that the difference between the hypocentral distances of these events is much smaller than their hypocentral distances themselves, we derive a system of linear equations for the differences in relative event locations. This formulation is similar to that of a master event location method that uses differences in phase arrival times. We applied our new method to earthquakes and tremors at Meakandake volcano, eastern Hokkaido, Japan. Comparison of the hypocentral distributions of volcano-tectonic earthquakes obtained thereby with those obtained from phase arrival times confirmed the validity of our new method. Moreover, our method clearly identified source migration among three source regions in the tremor on 16 November 2008, consistent with previous interpretations of other geophysical observations in our study area. Our method will thus be useful for detailed analyses of seismic events whose onset times are ambiguous.

RESIDUAL ANOMALIES AND DEPTH ESTIMATION

Geophysics ◽  
1953 ◽  
Vol 18 (4) ◽  
pp. 913-928 ◽  
Author(s):  
Svend Saxov ◽  
Kurt Nygaard
Keyword(s):  
Center Of Mass ◽  
Gravitational Effect ◽  
Depth Estimation ◽  
The Body ◽  
Random Errors ◽  
Vertical Derivative ◽  
Residual Gravity Anomaly ◽  
Concentric Circles ◽  
The Difference ◽  
Polygon Method

The residual gravity anomaly at a point is defined as the difference between the average anomalies along two concentric circles whose center is at the point, divided by the difference between the two radii or [Formula: see text] It is shown that the residual anomalies previously determined by the average circle or the average polygon method (Griffin, 1949) are included in the present definition. The second vertical derivative of g and, to some extent, the fourth vertical derivative of g (Peters, 1949) are also included. The relation between the residual anomalies and the depth of the subterranean masses is examined. It has been pointed out that the gravitational effect originating from a body with mass m is clearly apparent when the center of mass of the body has the depth [Formula: see text]. The influence from masses at a greater or lesser depth is almost eliminated. By avoiding the use of the center point in the figuring of the residual anomalies the influence of random errors is minimized.

scholarly journals Validity of flexicurve for the assessment of spinal flexibility in asymptomatic individuals

2020 ◽  
Vol 33 ◽  
Author(s):  
Marja Bochehin do Valle ◽  
Vinícius Hoffmann Dutra ◽  
Cláudia Tarragô Candotti ◽  
Juliana Adami Sedrez ◽  
Edgar Santiago Wagner Neto ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Reference Value ◽  
Relevant Information ◽  
Neutral Position ◽  
Maximum Flexion ◽  
Spinal Flexibility ◽  
Rms Error ◽  
The Difference ◽  
Asymptomatic Individuals ◽  
Flexion And Extension

Abstract Introduction: Spine problems are common, and assessment of spine flexibility provides relevant information; however, alternative evaluation methods need to be validated. Objective: To evaluate the concurrent validity of the Flexicurve using 3D videogrammetry as a reference value to assess spinal flexion and extension in the lumbar and thoracic regions. Method: The consecutive sample consisted of 39 individuals aged between 18 and 50 years. Two consecutive evaluations were performed by the same rater on the same day and at the same location: (1) Flexicurve and (2) 3D videogrammetry. The assessments were performed with the spine in the neutral position, followed by maximum flexion and extension. The range of motion (ROM) in the maximum flexion and extension positions was calculated in MATLAB® and defined as the difference between the maximum flexion or extension angle and that of the neutral position. Statistical analyses used were the Pearson Product-Moment Correlation coefficient, RMS error and Bland-Altman plot (α < 0.05). Results: The ROM between instruments was similar, with high correlations for thoracic flexion (r = 0.751), extension (r = 0.814) and lumbar flexion (r = 0.853), and RMS errors under 8°. The correlation for lumbar extension was moderate (r = 0.613) and the RMS error was more than 10°. The limits of agreement varied between ± 10º and ± 21º. Conclusion: The Flexicurve is valid for assessing maximum flexion and extension of the thoracic spine, and maximum flexion of the lumbar spine. We suggest caution in evaluating the maximum extension of the lumbar spine.

scholarly journals A Historical Review of Data and Information of Indonesian Mangroves Area

2019 ◽  
Vol 24 (2) ◽  
pp. 163-178 ◽  
Author(s):  
Aswin Rahadian ◽  
Lilik Budi Prasetyo ◽  
Yudi Setiawan ◽  
Ketut Wikantika
Keyword(s):  
Historical Review ◽  
Data Availability ◽  
Mangrove Forests ◽  
Quality Of Data ◽  
Mangrove Area ◽  
Sensing Technology ◽  
Comprehensive Information ◽  
Study Results ◽  
Depth Study ◽  
The Difference

Quantification of the mangrove area in Indonesia was very diverse, which is quantified in the pre and post development of remote sensing technology. This causes uncertainty comprehensive information of mangrove in Indonesia. The planners at national and international level of faced with the problems of uncertainty information that has implications for the quality of data availability. Therefore, it is important to develop a comprehensive of mangrove extent and distribution database. The method used in-depth study literature on various publications related mangrove mapping in Indonesia and comparative analysis. This study aims to identify comprehensive information mangrove forests of Indonesia and analyze the factors which cause diversity of quantification area and reliability of data. We found 42 publications containing data and information on Indonesia's mangrove forests area, with 17 sources including detailed information per province. The study results showed that the difference mangrove quantification area was influenced by several main factors including analysis periode, differences in the concept and mangrove boundaries, basic data and scale, method of mangrove mapping, as well as regional coverage. Keywords: historical data, Indonesia, mangrove area  

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