Fereydoon Nobakht Ersi; Abdolreza Safari; Mohammad Ali Sharifi
Abstract
The main purpose of the present paper is to use the ARMA probability models to model the time series of the daily positions of GPS permanent station.Daily Locations of the LLAS permanent station in the Southern California region have been selected from the SCIGN network, covering a period of seven years ...
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The main purpose of the present paper is to use the ARMA probability models to model the time series of the daily positions of GPS permanent station.Daily Locations of the LLAS permanent station in the Southern California region have been selected from the SCIGN network, covering a period of seven years from January 2000 to December 2006, to establish a time series of position and to analyze it. Based on the time series of the daily position and using the weighted least squares, the geodetic parameters such as linear trend, annual and semi-annualfluctuations, as well as offsets,have been simultaneously estimated for the LLAS permanent station. In this study, Auto correlation Functions (ACF) and Partial Auto Correction functions (PACF) are used as the study tools for identifying the time series behavior of daily position of GPS permanent station and provide the possibility to examine the dependency of the position time series daily data. Given that several different probabilistic models may be appropriate for a daily position time series, therefore,the Akaike Information Criterion has been used at the stage of identifying and selecting the useful model. In this study, numerical results show that the best autoregressive moving average (ARMA) probabilistic model for the LLAS permanent station is ARMA (1, 1) for direction N. Also, the ARMA (2, 1) probabilistic model is the most appropriate model for direction E, while the ARMA (1, 2) probabilistic model is the best model for direction U. After estimating an appropriate probabilistic model for the time series of the daily position of the GPS permanent station, it is possible to predict the time series of the position along with the trend and seasonal components.
Hasan Ali Faraji Sabokbar; Mahdi Mahdi; Reza Aghataher; Siamak Taghizadeh Ghalejuqi; Saeed Rahimi
Abstract
Disaster, crisis and then the search, rescue and reliefis a cycle frequently repeated in a country like Iran. In this cycle, commonly known as the crisis management cycle, we are constantly faced with a variety of data and outputs from the early stages, namely, determining the risk of areas to the post-crisis ...
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Disaster, crisis and then the search, rescue and reliefis a cycle frequently repeated in a country like Iran. In this cycle, commonly known as the crisis management cycle, we are constantly faced with a variety of data and outputs from the early stages, namely, determining the risk of areas to the post-crisis stages and retrieval, which are somehow related to the location. Collectinginformation both in the pre and post-crisis stages will notbe a very difficult task, as the damaged society is then almost relieved from panic and therefore resources permit the authorities in charge to gather information as requiredHowever, during the crisis andas long as the society is suffering from critical conditions, collecting information such as the depth of damages, damaged areas, risk-prone areas, dispersion of damages, resources, facilities and … will be very useful and obviously difficult. Thus, considering the lack of tools andappropriate technology in the country for gathering information during crisis conditions, this research has focused on gathering information in the crisis management response phase. In this regard, concepts of Telegeoinformatics (TGI) and its various architectures were presented and continued with designing a system for gathering information during earthquake crisis. Finally, an emergency response system was designed and was presented as a software package. Moreover, the model and software of this system was presented in UML for further development by other researchers who are studying in the same fields, which resulted in presentation of suggestions for development of this system using other technologies.
Mohsen Abbasnia; Taqi Tavousi; Mahmood Khosravi; Toros Hossein
Abstract
Recognizing and evaluating the climate changes in the coming decades is absolutely necessary for the purpose of appropriate environmental planning in order to adapt and mitigate its effects. In this research, the SDSM model was successfully calibrated and validated (1981-2010) tocomparatively analyze ...
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Recognizing and evaluating the climate changes in the coming decades is absolutely necessary for the purpose of appropriate environmental planning in order to adapt and mitigate its effects. In this research, the SDSM model was successfully calibrated and validated (1981-2010) tocomparatively analyze and explore the future maximum daily temperature variations over Iran forthe two future periods of (2041-70 and 2071-99) and based on the output of two general circulation models of atmosphere, namely, Hadcm3 and CGCM3 under the existing emission scenarios (A1B, A2, B1, B2), relative to the baseline period of 1981-2010. In other words, with regard to the uncertainty for the maximum daily temperature of the future data, downscaling was performed in 7 synoptic stations as the climatic representatives of Iran. Analysis of the output uncertainty showed that CGCM3 model under the B1 scenario among all different models-scenarios has had the best performance in simulating the future temperature. Also, the findings of the research on the studied stations indicate that the temperature in Iran in the middle and final decades of the 21st century increases in averagebetween 1 to 2 degrees Celsius, which based on different scenarios of the Hadcm3 model, this temperature increase has been higher compared to the CGCM3 model. In terms of spatial dispersion of the changes in the GIS environment based on the output of all scenario-models, the lowest temperature increase was observed at Bandar Abbas station located on the south lowland coast of Iran, and on the contrary, the temperature rise reaches the maximumat the Tabriz station located onthe northern latitudes and highland and mountainous regions of Iran. In total, the important and effective factors in the future changes of Iran's temperature can be classified into three groups: factors of altitude, latitude and atmospheric humidity, because, based on all the outputs of model-scenarios, the stations located on the northern latitude elevations of Iran will experience the highest temperature rise compared to the stations located on low-altitude and adjacent to the southern coast of Iran.
Amir Shahrokh Amini
Abstract
Facilitation and automation of the process of visual and geometric reconstruction is one of the issues considered in 3D modeling of environment, especially in urban areas. Since the positions of the lenses of a stereo camera are fixed relative to each other, it can be used to facilitate the modeling ...
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Facilitation and automation of the process of visual and geometric reconstruction is one of the issues considered in 3D modeling of environment, especially in urban areas. Since the positions of the lenses of a stereo camera are fixed relative to each other, it can be used to facilitate the modeling process. This article shows that producing 3D environment model can be facilitated by using stereo camera calibration data without the needto matchthe process, especially in the areas where the matching has problem because of insufficient information required. Moreover, using camera calibration information, geometric information and depth map of the environment can be extracted and produced without the need to define the specified scale between features. The results of practical studies and the reconstruction done in the urban environment were assessed later in this paper.
Leila Kashi Zenouzi; Hossein Saadat; Mohammad Namdar
Abstract
Aerial images are systematically utilized in most scientific contexts to undertake exploration and measurement operations. Image matching techniques for the acquisition of the ground truth in order to create thematic maps have always been facing difficulties and challenges. In this research, the LPS ...
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Aerial images are systematically utilized in most scientific contexts to undertake exploration and measurement operations. Image matching techniques for the acquisition of the ground truth in order to create thematic maps have always been facing difficulties and challenges. In this research, the LPS module from the ERDAS Imagine9.2 software was used to develop geomorphological landforms maps of the Harzand Chai watershed. The methodology used was based on analytical photogrammetric techniques (Two Dimension Affaine) using aerial photographs (1:40000). Harzand Chai watershed’sgeomorphological landforms maps were prepared using both traditional and photogrammetric methods. The map prepared by photogrammetric method was compared after field visit and matching the type of landforms with the acquisition of the ground truth, with the map prepared by conventional method that is used for creating thematic maps in our country. To perform a statistical test for evaluating the prepared map of the geomorphological landforms, 100 points were determined by the ERDAS Imagine9.2 software on the provided maps, and then about 62 points of them were taken using the GPS (Ground Positioning System) and the characteristics of each was written down. Statistical test was performed by Stratified random sampling method using ERDAS Imaginge9.2 software to examine two prepared maps.The resultant map was then matched with the real features and compared with the map developed by traditional methods used in the thematic mapping process in Iran. According to the findings of the statistical test, the percentage of the total accuracy for the geomorphological landforms map developed by the analytical photogrammetric technique was %95. The Kappa Index value for this map was estimated to be 0.9. These values for the geomorphological landforms map created by the conventional method were %84 and 0.76 respectively. Therefore, the geomorphological landforms map created by the analytical photogrammetric method was selected as the best representation of the geomorphological features of the Harzand Chai watershed.
Milad Salehi; Jamal Asgari; Alireza Amiri Simkooei
Abstract
Coordinate systems transformation has an important role in mapping activities, geodesy and spatial science. New and efficient methods are needed in order to increase the accuracy in the transformation between these systems.The main purpose of this article in the first part, is a local coordinates transformation ...
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Coordinate systems transformation has an important role in mapping activities, geodesy and spatial science. New and efficient methods are needed in order to increase the accuracy in the transformation between these systems.The main purpose of this article in the first part, is a local coordinates transformation in Isfahan City to UTM coordinates and vice versa. This method is based on the combined scale factor. So, the coordinates of 500 GPS stations in Isfahan City were used,and with reduction of distanceson the surface of the earth to the map, coordinates of the GPS points in the local system were calculated.Study on changing of combined scale factor for the GPS points of Isfahan City shows that if a unit scale factor is used for whole the city, in long lengths occurs a few decimeter differences and it is not suitable for accurate mapping. LIDAR is a mature remote sensing technology which can provide accurate elevation data for both topographic surfaces and above-ground objects. So in the second part of the article, we presented an algorithm to provide height interpolation for the points in the passage network of Isfahan City by using LIDAR data,because the inverse transformation from local system to UTM using new methods such as Rational Functions, needs vertical component in addition to horizontal position of points.A height bias of 30 centimeter has been detected in the LIDAR data using GPS control points. After removal of this systematic component, the final RMSE of LIDAR heights is 43 centimeters.
Sima Poorhashemi; Ali Asanlu; Mohammad Reza Mansoory Daneshvar; Hamid Nejad Soleimani
Abstract
Neighboring of Khorasan Razavi province with the two countries of Afghanistan and Turkmenistan, besides creating cultural and economic consequences in the border towns, has faced them with security challenges, especially in the context of strengthening the urban passive defense. One of the most importantfactors ...
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Neighboring of Khorasan Razavi province with the two countries of Afghanistan and Turkmenistan, besides creating cultural and economic consequences in the border towns, has faced them with security challenges, especially in the context of strengthening the urban passive defense. One of the most importantfactors related to the security challenges in these border towns is the lack of full identification of geographical factors especiallytopographic and geomorphological characteristics in the formulation of the principles and strategies of urban passive defense. Identifying environmental capabilities and constraints can playa more effective role in the principles of designing and passive defense in these cities. The topographic study of border regions and border towns is of particular importance which, If neglected, potential capabilities in security utilities for the creation of sensitive military centers of the country will be neglected too, and it will also increase the vulnerability of human societies and the physical structures of these cities over time.Zavyn city in North Khorasan provinceis considered as one of the towns close to the borderwith special topographic features. The main objective of this researchis to investigate the topographic and geomorphologicalcapabilities of the region with the passive defense approach and to analyze the security challenges and topographic problems of the study area using GIS and providing strategies based on the passive defense principles for the use of natural environment capabilities. From the results of this research, it can be noted that the formation of the urban shape in the present dispersed and decentralized dimensions of the city of Zavin is such that, the triple cores of the city from the defense perspective by strengthening and empowering of the texture as well as the conversion of the linear paths of access to the network graph In the current situation will be acceptable
Soroush Ojagh; Ali Asghar Ale sheikh; Mohammad Reza Malek; Mohammad Fallah Zezoli
Abstract
Nowadays, we are observing a huge revolution in the use of mobile equipment in all aspects of human life. They greatly facilitate our daily life by their numerous capabilities such as powerful processors and various embedded sensors. Reviewing the history of Geographic Information Science (GIS),one can ...
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Nowadays, we are observing a huge revolution in the use of mobile equipment in all aspects of human life. They greatly facilitate our daily life by their numerous capabilities such as powerful processors and various embedded sensors. Reviewing the history of Geographic Information Science (GIS),one can clearly recognize that real time spatial processes have been the most important concern over the years. On the other hand, data gathering phase is the most time and cost consuming phase in most practical projects. Using traditional way to perform data gathering phase, not only causes some noticeable problems such as: the difficulty of carrying paper maps, inevitable human made mistakes; but also create a deep gap for hitting the main goal of performing a real time spatial process. In this study, by developing a context-aware mobile information system that takes advantage of distributed architecture, we try to deal with those problems. Our ultimate goal is to replace our developed system by traditional methods for gathering spatial and descriptive data about nuisance jobs in Kermanshah, Iran. We assess and compare our system with traditional methods by comparing their results for collected data in 4 districts in a city by different groups of users. Statistical tests prove our developed system has more reliability and efficiency compared with traditional methods. At the end, the tendency of about 92% of user to use our system compared with traditional methods is another measurethat indicates our success in achieving the ultimate goal of this study.
Masoud Torabi Azad; Abbas Ali Aliakbari Bidokhti; Hossein Salehianfar
Abstract
Many hydrological conditions in the seas depend on temperature variation, and the rate of this parameter is an important determinant in the environmental conditions of each area. The variations in temperature and surface wind causes changes in the density of the sea water, and the change in density affects ...
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Many hydrological conditions in the seas depend on temperature variation, and the rate of this parameter is an important determinant in the environmental conditions of each area. The variations in temperature and surface wind causes changes in the density of the sea water, and the change in density affects the stability rate and mixing of the sea water column. In this research, the mutual effect of sea surface temperature (SST) on surface wind speed in the southern Caspian region (Mazandaran province) has been investigated. First, the sea surface temperature data was collected by the AVHRR sensor of NOAA satellite and surface wind speed data was collected by QuikSCAT satellite for an area of 340 × 220 square kilometers in the southern Caspian Sea. After analyzing the satellite data for sea surface temperaturel, its monthly and seasonal variations were drawn by Tecplot software for this area. It was found that the average seasonal temperature (spring and summer) of the eastern coast of southern Caspian Sea is 0.87 degrees centigrade more than that of the eastern coast. In order to investigate the mutual effect of the sea surface temperature on surface wind speed, four stations, A and D (in the western region), B and C (in the eastern region) were selected on the southern Caspian Sea. Then, the graph of temperature time series, temperature difference between the four stations, time series of wind speed and time series of wind speed difference between the four stations from 2000 to 2005 were plotted and compared for the spring and summer seasons. The results indicate that, with increasing temperature difference between the four stations, the difference in speed also increases in 80% of the cases for the summer and in 66% of the cases in the spring season.In these two seasons, because of the decrease in the activity of atmospheric systems, the temperature difference between the two stations has a significant effect on improving the wind speed difference.Average wind speed difference in the statistical period of 2000-2005 at the stations is 0.7 m/s for the spring and 1.37 m/s for the summer season.
Seyyed Hojjat Mousavi; Abolfazl Ranjbar; Mehdi Haseli
Abstract
Due to the changesin land use that is done mostly by human activities, changedetection of landuse and assessment of their environmental impact isessential for future planning and managing the resources. Therefore, the aim of this research is monitoring, detecting andtrending the landuse changes in Abarkooh ...
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Due to the changesin land use that is done mostly by human activities, changedetection of landuse and assessment of their environmental impact isessential for future planning and managing the resources. Therefore, the aim of this research is monitoring, detecting andtrending the landuse changes in Abarkooh basin (1976-2014) in orderto assess the environmental issues such as human stress onearth without considering tolerance capacity, and to identify the regions havingenvironmental stress.In this regard, after classification to identify the type of land uses and applying the base component analysis and tasseled cap functions and difference of images, satellite images data from Landsat, MSS (1976), TM (1990), ETM + (2000 and 2006) and OLI (2014)) sensors, and remote sensing techniques such as supervisory classification and accuracy assessment have been used to monitor the land use changes. The classification results indicate the enhancing of seven typesof land uses including urban lands, agricultural lands, wastelands, rocky lands, rangelands, clayey plain anddesert, and which have the highest accuracy of classification in 2014with kappa coefficient values of82.18%and total accuracy of 0.76. The trending results of changes in land use indicate an upward trend of the area in rangelands (5.65%), rockylands (2.52%),wastelands (3.63%) and agricultural lands (1.04%), and a downward trendof the area in urban land (4.33%), clayey plain (6.89%) and desert (6.03%). From the perspective of base component analysisand tasseled cap functions, 1.748% (306.4912 km2) and 3.989% (699.961 KM2) of the area of the study region were faced with increasing changes of landuse, and in general, the overall trend of the changes of increasing classes is upward. Most of the changes in land use are destructive and devastating, and in terms of spatial changes correspond to the area around human community centers suchas Abarkooh and Mehrdasht cities. It is evident that,due to the continuationof this trend, the Abarkooh basinbecomes a dead inactive ecosystem that lacksany ecological and biological production potential in the near future.
