نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی کارشناسی ارشد ژئودزی، دانشکده مهندسی نقشه برداری و اطلاعات مکانی، پردیس دانشکده های فنی، دانشگاه تهران
2 استاد تمام دانشکده مهندسی نقشه برداری و اطلاعات مکانی، پردیس دانشکده های فنی، دانشگاه تهران
3 استادیار دانشکده مهندسی نقشه برداری و اطلاعات مکانی، پردیس دانشکده های فنی، دانشگاه تهران
چکیده
در سال‌های اخیر سازمان های نقشه‌برداری کشور، جغرافیایی،ثبت و املاک کشور و به‌صورت محدود برخی شهرداری‌ها برای ارائه خدمات تعیین موقعیت آنی دیفرانسیلی اقدام به ایجاد سامانه‌هایی کرده‌اند. این سامانه‌ها هرچند برای مقاصد نقشه‌برداری سریع در کشور مؤثر و مفید بوده‌اند، اما تأمین‌کننده تعیین موقعیت دقیق در مناطق ساحلی و فراساحلی کشور برای پاسخگویی به نیازهای ناوبری و اکتشاف و استخراج منابع دریایی در میادین نفتی نیستند. این در حالی است که کشور دارای مرز آبی طولانی در جنوب و شمال بوده و در برنامه‌های توسعه کشور، اقتصاد دریا محور در اولویت قرار گرفته است. گام اصلی در ایجاد یک سامانه تعیین موقعیت دیفرانسیلی آنی انتخاب مکان مناسب برای استقرار ایستگاه‌های تعیین موقعیت دائم است. لذا مکانیابی ایستگاه‌های شبکه کینماتیک آنی در جنوب کشور موضوع این تحقیق قرار گرفت. برای این منظور ابتدا ماتریس مقایسه زوجی لایه‌ها و زیرلایه‌های اطلاعاتی مورد نیاز، بر‌اساس نظر پنج خبره در این امر به روش دلفی به‌دست آمد. سپس با استفاده از نرم‌افزار Matlab به روش تحلیل سلسله مراتبی فازی(Fuzzy Analytic Hierarchy Process) برنامه نویسی و وزن هر لایه و زیرلایه محاسبه شد. سپس بر‌اساس وزن‌های به‌دست آمده از تجزیه و تحلیل ماتریس‌های مقایسات زوجی برای هر یک از زیر لایه‌ها، کلاسه‌بندی لایه‌ها در محیط GIS انجام پذیرفت؛ در نهایت با ادغام لایه‌ها به روش همپوشانی شاخص وزندار (Weighted index overlay) بر‌اساس وزن‌های به‌دست آمده برای هر لایه، مکانیابی برای استقرار ایستگاه‌های دائمی بهینه یابی شده است. جزئیات محاسبات و نتایج حاصل در مقاله ارائه شده است.
کلیدواژه‌ها
عنوان مقاله [English]
Site selectionfor Network Real-Time Kinematic stations on the South Coast using Fuzzy Analytic Hierarchy Process
نویسندگان [English]
- Farzad Moradi 1
- Ali Reza Azmoudeh Ardalan 2
- Parham Pahlavani 3
1 Master of Geodesy - Faculty of engineering surveying and spatial information - University of Tehran
2 Professor, Faculty of engineering surveying and spatial information - University of Tehran
3 Assistant professor, Faculty of engineering surveying and spatial information - University of Tehran
چکیده [English]
Introduction
Recently, National Cartographic Center, the Organizationfor Registrationof Deeds and Properties, and alsoon a limited scale some municipalities have developed systems to provide real-time differential positioning services. Although these systems have proved to be efficient for quick mapping purposes in this country, they do not provide accurate differential positioning in coastal and offshore areas and thus cannot meet the needs of navigation and exploration and extraction of marine resources in oil fields. However, Iran has long maritime boundary in its south and north, and maritime economy is considered to be a priorityin its development planning. Since site selection for permanent positioning stationsis considered to be the main step of creating a real-time differential positioning system, finding the most suitable location for permanent positioning stations in the south of the country was selected as the purpose of the present study. To reach this aim, pairwise comparison matrix of the required information layers was first constructed using Delphi methodbased on the opinion of 5 experts, and in the next step, computer coding was performedin MATLAB using Fuzzy Analytic Hierarchy Process to compute the weight of each layer and sublayer.Then, layers were classified in GIS environment based on the weights obtained from the analysis of pairwise comparison matrices for each sublayer. Finally, layers were integrated usingweighted index overlay analysis methodto select optimal sites for permanent stations based on the weights obtained for each layer. Details of the calculations and the results are presented in the article.
Materials and Methods
High efficiency of analytichierarchyprocess and spatial information systems in management and analysis of spatial data have led to the creation of a highly efficient environment in which various stages of different analysis such as site selection for permanent GNSS stations can be performed. One of the advantages of this procedure is that the analysis can beupdated in the shortest possible time and the result can be depicted visuallyat any stage of decision makingwith a simple changing of the values (weights) of each input data based on the expert opinion. Thisgreatly impacts experts' understanding of changes in the studyarea. Accordingly,fuzzy analytichierarchyprocess method is used within the GIS environment in the present study.
Results and Discussion
The present study addresses the issue of site selection for permanent GNSS stations. In the first step,pairwise comparison matrix was created for the criteria and sub-criteria and filled in by 5 experts. Then, layers were classified in GIS environment based on the weights obtained for each sub-layers of pairwise comparison matricesand the codes written in MATLAB. Finally, suitable locations for permanent GNSS stations were obtainedby integrating the layers usingweighted index overlay.
Conclusion
The present study has provided the results of optimal site selection for GNSS permanent stations. These selected sites meet the needsofprecise positioning in the coastal areas of the country and can be used in navigation and exploration and extraction of marine resources and oil fields. Afterthe selection of southern coasts as the study area, 7 criteria (proximity to urban areas and facilities, slope, distance from faults, distance from access roads, soil type, distance from rivers and distance from railways) were selected based on the expert opinion. A pairwise comparison matrix was createdfor these criteria and sub-criteria and 5 expert experts were consulted in this regard. Expert opinions were analyzed using codes written in MATLAB software andFuzzy Analytic Hierarchy Process method and thus, the weight of each criterion and sub-criterion was obtained. These weights were then integrated using the geometric mean method and the final weight of each layer and sublayer was determined. Using Arc map software, these weights were applied to different layers and sublayers, and finally, optimal locations for permanent GNSS stations were divided into 5 classesof very good, good, medium, bad, and very bad stations. Good and very good classes can be considered as optimal places forcontinuously operating reference stations.
کلیدواژه‌ها [English]
- Continuously Operating Reference Station (CORS)
- Fuzzy Analytic Hierarchy Process (F-AHP)
- Network Real-Time Kinematic (NRTK)
- Weighted Index Overlay
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