نشریه علوم و فنون نقشه برداری
سال دوم شماره 2 (پیاپی 6، آبان 1391)

Route finding is exercised directly or indirectly in many scientific studies. This issue is addressed based on different perspectives, various methods, and in numerous applications. Route finding is considered as an optimization problem for which Dijkstra algorithm is used most frequently. Various techniques have been developed to enhance the performance of the algorithm. Recently, the use of belief-desire-intention architecture of agent-based model has been burgeoning in spatial sciences. Such a model is based on intentional systems, which the behavior of the entities can be described based on as desire, want, hope, belief information. Despite the versatility of this model, its concepts are burgeoning and as such it needs further analyses and investigation. In this paper, a novel model is introduced for solving route finding based on belief-desire-intention architecture of agent-base model. Based on this architecture, a novel algorithm is introduced to solve the optimum path between start and end nodes. The proposed algorithm will be able to provide the optimum solution for a problem in a vector network. At the end of this article, a sample of rout finding is discussed to show the efficiency of our proposed model. The evaluation results showed how the chosen path depends on the behavior of the agents. If suitable behaviors are selected for agents, acceptable results will be reached.

One of the most recent and promising atmospheric remote sensing technique is the GPS Radio Occultation(GPS RO). Its importance has been increasing the last decade, since the first related mission (the GPS/MET) highlighted its possibilities. The GPS RO technique is based on the inversion of excess-phase measurements related to the signal transmitted by a GPS satellite and detected by a GPS receiver placed on low earth orbit(LEO). In this study, based on the occultation theory, produced the refractivity, pressure and temperature profiles from the earth surface to above 50 Km. The results showed a good agreement between produced parameters and corresponding in radiosonde and global models such as the ECMWF and NCEP. The low accuracy of retrieved temperature profiles in the lower troposphere is one of the weaknesses of this technique. We proposed a new method to improve the accuracy of temperature profiles in these regions. Surface temperature (from the Europian Center for Medium range Weather Forecasting (ECMWF)) with the temperature generated above lower troposphere are combined in a linear model and the solution is obtained through a least squares method in this range of altitudes. Also 81 temperature profiles that produced in different latitudes and seasons were compared with Radiosondes, Constellation Observing System for Meteorology, Ionosphere and Climate(COSMIC) RO profiles, ECMWF and National Centers for Environmental Prediction(NCEP) global models. Obtained results show the accuracy of modified temperature profiles is 1 Kelvin below 7 Km altitude which is much better than that of COSMIC RO profiles. While the temperatures generated by the COSMIC mission in these areas are erroneous up to 6 K. Additionally, the accuracy of the obtained profiles is the same as that of COSMIC profiles above 7 Km. Both of them are precise to 0.5 K in 7-17 Km and at altitudes above 17 Km approaches 0.7 K.

One of the most important climatic changes in urban areas is temperature rise due to the land cover changes. The relative increase of temperature in urban areas respect to the surroundings lead to phenomenon called Urban Heat Island. The phenomenon causes serious effects in the urban climate so its monitoring is important. Heat island phenomenon of different dimensions can be verified that one of them is the surface temperature changes. In this study, land surface temperature changes over the past 12 years investigated. Land surface temperature has been calculated with two Day/Night and Generalized Split Window algorithms, using MODIS thermal bands. The land surface temperature changes in the last 12 years period in 14 cities with different climatic conditions has been studied in the day and night. Then urban area has been compared to surrounding suburbans. The results show that land surface temperature in urban area doesnt rise and even in some cases there is a decreasing trend. The effects of heat island occur in the evening as we expect. Furthermore day and night temperatures in most of these cities tend to close together and the temperature difference between cities and their suburbanes are declining based on observations.

SAR images are important data for observing the earth in the all weather conditions. But the speckle noise contaminated the SAR images obstructs the application of them. Speckle noise is primarily due to the phase fluctuations of the electromagnetic return signals. In this paper, we investigate the effect of speckle on the change detection result. Two cost functions are used in our change detection algorithm. One is based on Minimum Mean Squared Errors and the other one is composed of the MMSE and a de-speckled filter. Change detection method is based on the genetic algorithm. The difference image is first computed by the input images and then divided into two separated changed and unchanged regions, according to the change mask realization produced by Genetic Algorithm. A set of real data acquired from ASAR sensor of Envisat satellite is used to evaluate the performance our method. The results show that the proposed method improves the detection procedure reducing the noise contamination.

Nowadays different aerial and space digital imaging systems is used for variety of application such as Photogrammetry, remote sensing and image processing. One of the newest and the most applicable of aerial sensors which it's images is using to produce and update the large-scale maps, is UltraCamD imaging system. On the other hand, with availability of this sensor as one of the most important sensors in country for photogrammetric applications, and existence of captured images with different scales from areas with different properties, the main purpose of this paper is geometric performance measurement of these images with ground control points and different mathematical models. In this paper three sequential images of UltraCamD sensor is take into account for modeling image residuals, space resection and intersection. Mathematical models that used in this research are most common models in Photogrammetry and to assess the results of these models, the RMSE of check points is taking into accounts. Result shows that the use of colinearity function in case of self calibration with additional parameters is the best model to eliminate systematic image errors. According to other models result, UltraCam images include high geometric performance and sub-pixel accuracy is reachable. So these images have sufficient potential to produce and update large-scale maps.

Landslide is one of natural hazard which often occur in mountainous regions with high precipitation and seismic activity. Iran because of having vast mountainous areas is one of susceptible countries in occurrence of landslide. Case study area of this paper is an instable slope which a village named Gougerd is located on downstream of it. This village is located near Khoy city northwest of Iran in western Azerbayjan province. The purpose of this study is using two different methods in the Geomatics field in order to monitor the probable downward movement of the Gougerd village slope. Differential SAR interferometry (DInsAR) and Global Positioning System (GPS) observation is used as beneficial tools to evaluation and monitoring of surface displacement caused by landslide. 24 SAR images are provided spanning 2003-2010 for InSAR technique processes to study past mechanism of Gougerd slope. Displacement field map and time-series of selected PS pixels are the final products of InSAR analysis which show the range of the occurred mass movement along sensor line-of-sight. Also in order to more accurate evaluation and consideration a geodetic network with ~ 20 stations are constructed on the slope. Dual frequency GPS receivers are applied to do geodetic observations of this network to study present mechanism of the slope by determining the precise horizontal movement at some specific sparse locations. Static mode of GPS observations is done in 3 epochs during 2010-2011 with time interval of about 7 month. Using DInSAR technique beside GPS Geodetic observation method released useful qualitative and quantitative information about downward movement of Gougerd slope. Displacement analyses of both used methods represent significant movement especially on the upstream of Gougerd slope affected by landslide creeping. GPS and InSAR results showed suitable compatibility and prove that these two methods are complementary each other appropriately to illustrate surface slow movement like landslide creeping as we used it in this research.

Presenting location-based services (LBSs) in mobile information environments has been developing quantitatively and qualitatively each day. The most important ingredient of such services is map. The fundamental map elements like information contents, scale and other graphical items are related to the spatial resolution of user or device. Thus, map resolution is an integral part of LBSs. One of the less-attended issues so far is determining the resolution of maps that are going to indicate some information to users. In this paper, a context-aware approach is presented to determine the resolution of maps used in LBSs. In fact, the map’s resolution is computed using fuzzy inference engine based on two basic contexts of location and time. In this method, user’s location and the time of request are inputs to the fuzzy inference system. The map’s resolution for indicating information to user is the system’s output. Fuzzy rule base is developed by grouping and consulting users. The proposed approach was implemented for a group of faculty members and the results proved the applicability of the method for other user groups.

A fuzzy predictive model is compatible with the multiclass and continuous nature of geodata and can properly handle inherent informational fuzziness in most geodata. Although the fuzzy based approaches are been used by different researchers and varied deposits, the structure and pattern of these method were almost similar. In this study, we produce a mineral potential map for the porphyry copper mineral deposit of Nochoun, south east of Iran. In order to improve the conventional methods, we used a fuzzy inference system (FIS) for preparing geophysical and geochemical factor maps. These factor maps are integrated by an appropriate inference networks and mineral potential map was produced. Results of the prepared mineral potential map are in a good accordance with drilling data (80.7 % in 5 class and 87.1 % in 3 class classification). Also, using FIS in preparing factor maps, has improved the compatibility of mineral potential map, (almost 10% in 3 classes and 7 % in 5 classes classification).

This paper investigates the ability of video to integrate with urban spatial data. Video can represent the urban environment continuously with real images which is desirable in many applications. By providing camera pose in each video frame by means of GPS/INS or image processing (structured video), one can measure 3D coordinate and space distances of features inside the video. Having 3D coordinate, symbolization is possible and user can save or retrieval attribute data. A measureable video with ability to save and retrieval spatial data is called 3D Video GIS. In this paper, the methodology and difficulties of a real 3D Video GIS is presented.