Khosro Khajeh (Translation)
Volume 3, Issue 9 , January 2018, , Pages 48-51
Abstract
My first contact with GIS was in 1965 at a meeting at the Harvard University and Michigan Institute of Technology’s Joint Center for Urban Studies, and I came across a good accident by sitting next to Howard Fisher. At that time, Howard Fisher intended to leave the University of Chicago and was ...
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My first contact with GIS was in 1965 at a meeting at the Harvard University and Michigan Institute of Technology’s Joint Center for Urban Studies, and I came across a good accident by sitting next to Howard Fisher. At that time, Howard Fisher intended to leave the University of Chicago and was therefore visiting Harvard University.
Fisher had recently invented SYMAP, a computer-based mapping application that worked on linear printer technology, but was not yet at operational state. I immediately took advantage of the opportunity; relying on his words about the SYMP abilities and the requirements of his doctoral thesis, I convinced him to allow me to carry out experiments using his original program. With the supervision and guidance of Fisher, I implemented the first applied SYMP test in my studies of Boston's central perceptual geography. It was to some extent due to this work that I was first appointed as an Assistant Professor at the Harvard School of Design, and started working as a novice researcher in a laboratory known today as the computer cartographic labs.
Khosrou Khajeh (Translator)
Volume 8, Issue 31 , November 2009, , Pages 6-8
Abstract
Today the managers and planners have a need for three-dimensional (3-D) display of objects, especially in urban environments, which is inherent in relevant processes. In order to fulfil such need, a digital camera is set on a Total Station Theodolite that is able to perform accurate video recording of ...
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Today the managers and planners have a need for three-dimensional (3-D) display of objects, especially in urban environments, which is inherent in relevant processes. In order to fulfil such need, a digital camera is set on a Total Station Theodolite that is able to perform accurate video recording of vertical surfaces such as building facades. In this paper, while examining an example of theodolites equipped with digital video cameras, the research problems and constraints in this regard were discussed.
Khosrou Khajeh (Translator)
Volume 14, Issue 55 , November 2005, , Pages 40-47
Abstract
Recently, in Mexico, using digital maps of the 1970s, 1993 and 2000, a profitable data bank was established to measure the extent and characteristics of Land Use and Cover Change (LUCC) across the country. In order to advance this plan, an existing map of land use and cover available on a scale of 1:250,000 ...
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Recently, in Mexico, using digital maps of the 1970s, 1993 and 2000, a profitable data bank was established to measure the extent and characteristics of Land Use and Cover Change (LUCC) across the country. In order to advance this plan, an existing map of land use and cover available on a scale of 1:250,000 was revised in order to determine the input data in terms of scale, classification scheme and mapping method. The digital maps prepared in three different dates (i.e., late 1970s, 1993 and 2000) were merged into a GIS database after being reviewed, evaluated and corrected. In order to improve the credibility of the data bank, efforts were made to evaluate the accuracy of the method and the digitization procedure and to detect and correct the unpredictable changes resulting from thematic errors in the map. The digital maps were put onto each other to create LUCC maps and calculate transition matrices and conversion rates. Based on this data bank, the deforestation rate between the years 1976 and 2000 was estimated as 0.25% and 0.76% per year for the moderate and tropical forests respectively.
Khosru Khajeh (Translator)
Volume 14, Issue 54 , August 2005, , Pages 29-31
Abstract
Since it is possible to achieve precision of two centimeters (or better) for orthometric altitudes (perpendicular to geoid) derived from GPS, this paper is intended to provide a brief and practical guide to the use of GPS devices, methods of reference determination, data collection and geoid models that ...
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Since it is possible to achieve precision of two centimeters (or better) for orthometric altitudes (perpendicular to geoid) derived from GPS, this paper is intended to provide a brief and practical guide to the use of GPS devices, methods of reference determination, data collection and geoid models that provide surveyors with high-precision orthometric altitudes. Although this paper is basically written for American surveyors, all other surveyors can benefit from the experiences collected in this paper as well. Achieving two-centimeter precision for GPS-based orthometric altitudes can be achieved using iterative, radial and fast static GPS techniques along with a high resolution geoid model. These methods can be implemented in an area of less than 30 km2, and since field GPS methods and observation time periods are not directly proportional to the length of the base line, these methods can not be immediately applied to large-scale projects (i.e., Lands with areas more than 30 km2). The author of this paper intends to present a brief and practical guide and is not to provide a substitute for the GPS manual, but to create an incentive for surveyors to study the device's manual with great attention.
Khosrou Khajeh (Translator)
Volume 14, Issue 53 , May 2005, , Pages 35-38
Abstract
The geoid model currently used by Australia has been calculated using combination of the global model of OSU91A and the Australian Gravity Information Database published in 1980. Currently, due to the availability of advanced data and more accurate computational methods, Australian geoid accuracy can ...
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The geoid model currently used by Australia has been calculated using combination of the global model of OSU91A and the Australian Gravity Information Database published in 1980. Currently, due to the availability of advanced data and more accurate computational methods, Australian geoid accuracy can be improved. In 1998, the Australian Research Council allocated a budget for a group project to seek a new generation of gravimetric geoid model for Australia. While presenting some of the research that is currently in its final stages, this paper discusses providing new data, selecting the most appropriate global model that the new Australian geoid will be based on, and a Digital Terrain Model (DTM) to calculate the effects of the Earth on geoid. Improving the geoid model makes it possible for field surveyors to implement high-precision topographic mapping with the aid of GPS on the basis of Australian elevation (Oustralian Height Datum-AHD) while decreasing required time and cost. First-hand reports and experiences suggest that the use of gravimetric geoid with along with GPS, as an option for immediate alignment, can bring about save of time and cost in a range between 100% and 300%.
Khosrou Khajeh (Translator)
Volume 13, Issue 51 , November 2004, , Pages 31-35
Abstract
For geographic applications such as surface flow models, 3D visualization, simulation and analysis of visibility potential gaining information about land features (land’s lay) is a necessity. Basically, the Digital Terrain Model (DTM) includes sampling few points of the real world. Interpolation ...
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For geographic applications such as surface flow models, 3D visualization, simulation and analysis of visibility potential gaining information about land features (land’s lay) is a necessity. Basically, the Digital Terrain Model (DTM) includes sampling few points of the real world. Interpolation is still a difficult task in order to reconstruct a continuous surface of sample points. In this paper, the author attempts to discuss current issues of DTM production and interpolation technology including continuous advancement in information technology and increasing need of users to digital land models.
Khosrou Khajeh (Translator)
Volume 13, Issue 52 , February 2004, , Pages 30-36
Abstract
In order to achieve a precise method of converting PAN photography from a spatial image to a spatial object, a mathematical model has been designed in which at least one GCP (Ground Control Point) is used to determine the external justification of images. This mathematical model was originally prepared ...
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In order to achieve a precise method of converting PAN photography from a spatial image to a spatial object, a mathematical model has been designed in which at least one GCP (Ground Control Point) is used to determine the external justification of images. This mathematical model was originally prepared for Spot satellite imagery, which uses multicolinear equations to provide a satellite path model, while the satellite height difference would be formulized as a function of time using high-order polynomial modeling. Initial orbital information is obtained from the given data and refinement is also done using the iterative least squares solution. This mathematical model was tested for three different states: (1) a single image (2) strip (caused by a detector during orbit passage), and (3) a stereo pair. For states (1) and (2), a mean error of 9.1 m in width and 7.6 in length can be obtained by using a ground control point (GCP) for modeling. Using a ground control point was identified from a map of scale 1:50000. Accuracy was 38.3 meters in width, 42.6 meters in length, and 23.8 in height for the stereo pair. The results confirm the model and somewhat suggest ideas with which PAN (IRS-1C) will be able to influence the future developments of photogrammetry and cartography. The software mentioned in this paper for modeling orbit altitude is part of SOFTSPACE, a digital photogrammetric station for working with IRS-1C PAN and Spot imagery stereo data, a multifunction software package for preprocessing, photo conversion into map, a Digital Terrain Model (DTM) and features compilation modules.
Khosrou Khajeh (Translator)
Volume 13, Issue 52 , February 2004, , Pages 56-58
Abstract
The widespread use of GPS has been accompanied with great deal of success and has already evolved into a true 3D instrument. Therefore, the major attempt to complete a GPS project is often focused on elevation issues. This paper examines the GPS elevation-determination limits, including GPS measurements, ...
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The widespread use of GPS has been accompanied with great deal of success and has already evolved into a true 3D instrument. Therefore, the major attempt to complete a GPS project is often focused on elevation issues. This paper examines the GPS elevation-determination limits, including GPS measurements, geoid issues and datum. Next, the GPS elevation-determination is described with a look at three applications of deformation control, GPS mapping with instantaneous processing, and device control and guidance.In practice, GPS elevation-determination usually involves three aspects:1 - Oval height measurement with GPS2 - Applying the geoid model3 - Adjustment of the orthometric (or normal) height so that the altitude base is appropriate.All of these issues create limitations, and the importance of each one, depending on the breadth and magnitude of the GPS mapping, is different, so here some of these limitations are studied in greater details.
Khosrou Khajeh (Translator)
Volume 12, Issue 46 , August 2003, , Pages 30-34
Abstract
The rapid growth of the world's population and the expansion and development of cities, urban suburbs and rural areas, and the steady and unrelenting increase of human activities on the earth, all indicate the necessity of more detailed, diverse and up-to-date ground information (GI) in all spatial and ...
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The rapid growth of the world's population and the expansion and development of cities, urban suburbs and rural areas, and the steady and unrelenting increase of human activities on the earth, all indicate the necessity of more detailed, diverse and up-to-date ground information (GI) in all spatial and temporal aspects. This reinforces the role of photogrammetry, in particular its refining capacities for production of ground information (GI) from high-resolution aerial or satellite imagery. In this paper, the author has focused on factors that affect the efficiency of this process.
Khosrou Khajeh (Translator)
Volume 12, Issue 45 , May 2003, , Pages 25-27
Abstract
Application of photogrammetry in industrial environments requires full automation capable of functioning without human supervision. The main elements in such systems are the high resolution of cameras, the strength and durability of cameras in terms of their geometric shape and structure and the frequency ...
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Application of photogrammetry in industrial environments requires full automation capable of functioning without human supervision. The main elements in such systems are the high resolution of cameras, the strength and durability of cameras in terms of their geometric shape and structure and the frequency of their response. In this regard, a series of modern cameras have been designed that provide both 2000 × 3000 and 70000 × 40000 sensors and so remove the usual obstacles that preclude the acquisition of precision and show great potential for high precision metrological 3D images.
The high efficiency and features of the 3D metrology system have made it possible for the few but highly skilled producers to find a place in the global market. Most of these systems can be characterized by the following features: Specific objectives (reflective targets, light emitting diodes (LEDs), high contrast object characteristics, points and patterns image, etc. that are used to produce signals representing the desired points in order to achieve optimal contrast.
Khosru Khajeh (Translator)
Volume 11, Issue 43 , November 2002, , Pages 25-28
Abstract
The dominant solution of GIS in the early 1990s was a solution whose program could run on an independent workstation or personal computer. In this paper the investigation of previous solutions in which a database was kept on a large host computer and end users worked on data at ambiguous network terminals ...
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The dominant solution of GIS in the early 1990s was a solution whose program could run on an independent workstation or personal computer. In this paper the investigation of previous solutions in which a database was kept on a large host computer and end users worked on data at ambiguous network terminals has been removed. In this paper, the author attempts to present general lines of the influence and impact of the GIS technology on the level of local and global networks.Owing to the widespread advancements that have emerged over the years in hardware and software, today the network architecture of the GIS technology from a central data bank with a GIS server which is capable of maintaining, managing and efficient delivery of data, has been realized. Therefore, networking, communications and the ability to work in various environments are among central issues. For successful use of the GIS technology on the Internet, web users need to know and understand its principal characteristics.
Khosrou Khajeh (Translator)
Volume 11, Issue 42 , August 2002, , Pages 34-37
Abstract
Although our universe and all objects in it are three-dimensional (3D), nonetheless commercial GIS usually reduces spatial data (spatial data) to two-dimensional (2D) due to different data considerations. If the entire range of the known applications of 2D GIS is to become available in a 3D GIS, certain ...
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Although our universe and all objects in it are three-dimensional (3D), nonetheless commercial GIS usually reduces spatial data (spatial data) to two-dimensional (2D) due to different data considerations. If the entire range of the known applications of 2D GIS is to become available in a 3D GIS, certain appropriate topological and geometric information structures become necessary.The author of this article reviews the current problems of access to 3D GIS and provides answers that result from his research efforts.
Khosrou Khajeh (Translator)
Volume 11, Issue 41 , May 2002, , Pages 27-29
Abstract
The extraction of small scale maps from large scale maps requires a generalization process. The authors of this paper describe a system for the automatic extraction of leveling lines which uses the generalization of individual lines based on a natural principle. In order to extract new levels from two ...
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The extraction of small scale maps from large scale maps requires a generalization process. The authors of this paper describe a system for the automatic extraction of leveling lines which uses the generalization of individual lines based on a natural principle. In order to extract new levels from two initial adjacent levels, a middle-axis algorithm has been used. The system has been extensively tested using real data.Visual surveys show that the quality of the generalized levels is very favorable.
Khosrou Khajeh (Translator)
Volume 10, Issue 37 , May 2001, , Pages 43-46
Abstract
For more than three decades, measurement of distance has been carried out during routine and normal surveying tasks. Today, thanks to advancements in computer technology, automatic collection and processing of large volumes of field data and laser fields have become possible. Short-distance laser 3D ...
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For more than three decades, measurement of distance has been carried out during routine and normal surveying tasks. Today, thanks to advancements in computer technology, automatic collection and processing of large volumes of field data and laser fields have become possible. Short-distance laser 3D mapping systems that are derived from these advancements, have the ability to provide accurate computer models with great details from a wide range of objects including construction works, industrial complexes, works of art and architecture within very short periods of time. The authors of this paper discuss the operation and possibilities of systems for preparation of short-distance laser 3D mapping. They also compare the supporters and critics of this technique with the supporters and critics of photogrammetric system.
Khosrou Khajeh (Translator)
Volume 9, Issue 35 , November 2000, , Pages 34-37
Abstract
The surveying profession has been influenced by a rapid evolutionary path in terms of technology and innovation in recent years. Today, most surveyors generally use digital level, laser planes with mapping cameras known as total stations and GPS. Nevertheless, ISO (International Standard Organization) ...
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The surveying profession has been influenced by a rapid evolutionary path in terms of technology and innovation in recent years. Today, most surveyors generally use digital level, laser planes with mapping cameras known as total stations and GPS. Nevertheless, ISO (International Standard Organization) has so far been able to provide certain and specific standards for such new devices. ISO is still busy updating and implementing its early standards for older devices, such as EDM, theodolites, and levels. This paper presents the general and specific needs of surveyors for standards. Therefore, we describe two compound and simple field test procedures for determining the accuracy of leveling devices. The purpose of the compound procedure is to determine leveling precisely, and the simple procedure is considered for leveling in construction sites.
Khosrou Khajeh (Translator)
Volume 9, Issue 34 , August 2000, , Pages 53-55
Abstract
GPS, despite its all advantages over other surveying methods, shows weaknesses in certain conditions of field operations. When implementation of part of surveying operations by GPS is not possible, there will be need for another tool, such as Optical Total Station machines.In this paper, it is tried ...
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GPS, despite its all advantages over other surveying methods, shows weaknesses in certain conditions of field operations. When implementation of part of surveying operations by GPS is not possible, there will be need for another tool, such as Optical Total Station machines.In this paper, it is tried to mention the potentials of utilization created by combination of the two methods. In this paper, all emphasis was placed on field operations of surveying process. Following implementation of a research plan for preparation of planimetric maps through combination of two technologies, we have achieved results which show clear temporal improvement of surveying process. The results obtained from this plan show a temporal improvement between 27 to 73 percent compared to the same task of surveying implemented by only one of the technologies.
Khosrou Khajeh (Translator)
Volume 9, Issue 36 , February 2000, , Pages 23-25
Abstract
Over the past decade the need for elevation information in the city has risen enormously. This includes controlling vertical deviations of buildings, recording the 3D status of service facilities such as water supply networks, sewage network and electricity transmission lines, as well as creating precise ...
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Over the past decade the need for elevation information in the city has risen enormously. This includes controlling vertical deviations of buildings, recording the 3D status of service facilities such as water supply networks, sewage network and electricity transmission lines, as well as creating precise urban 3D models for urban planning purposes. The question dealt with in this paper is how to expand the scattered 3D data by adopting an economical and cost-effective method. The author of this paper presents his examinations based on the experiences gained in Stockholm.
Khosrou Khajeh (Translator)
Volume 8, Issue 30 , August 1999, , Pages 44-47
Abstract
Application of the GIS technology and the quality of its results depend on access to digital geographic data of acceptable quality. Conversion of analogue maps into digital ones is a way of producing digital geographic data.Unfortunately, analogue maps are in most cases out-of-date. For vast countries, ...
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Application of the GIS technology and the quality of its results depend on access to digital geographic data of acceptable quality. Conversion of analogue maps into digital ones is a way of producing digital geographic data.Unfortunately, analogue maps are in most cases out-of-date. For vast countries, production of new maps according to ground-based observations is very difficult due to high costs and excessive time needed for their completion. This paper presents a framework for updating available digital geographic data as an alternative to revision of customary maps.
Khosro Khajeh (Translator)
Volume 7, Issue 25 , May 1998, , Pages 19-22
Abstract
This paper examines the main technological aspects of digital models of elevation points and digital orthophotos using the Russian satellite’s photos. Satellite images of (TK-350) and (TVR-1000) propose an economic attitude that makes access to such digital photos possible.
The basis of this theory ...
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This paper examines the main technological aspects of digital models of elevation points and digital orthophotos using the Russian satellite’s photos. Satellite images of (TK-350) and (TVR-1000) propose an economic attitude that makes access to such digital photos possible.
The basis of this theory is that common photogrammetric processing of images is carried out based on navigational data. In this way, there is no longer any need for ground control points, and (TK-350) small-scale images are used as the metric basis for creating (DEM), and also the (TVR-1000) large-scale images contain thematic information for access to ground reference and have been designed for ortho production, and in this way the characteristics of precision of digital products are determined.
In recent years, Russia has vastly introduced the (TK-350) and (TVR-1000) satellite images into global markets. The unique characteristics of these images have distinguished them in global arena due to economic advantages in preparation of maps of vast areas. These two images make production of earth’s digital maps with a precision comparable to 1:50000 maps and large-scale topographic maps possible.
Khosro Khajeh (Translator)
Volume 6, Issue 22 , August 1997, , Pages 62-64
Abstract
In recent years, the developments in creating and extracting spatial data have led to emergence of operational tools in the form of geographic information systems. It is these developments that have opened our eyes to infrastructural issues about the manner and reasons of these systems’ operation. ...
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In recent years, the developments in creating and extracting spatial data have led to emergence of operational tools in the form of geographic information systems. It is these developments that have opened our eyes to infrastructural issues about the manner and reasons of these systems’ operation. What is a geographic information system? A tool? A piece of a software? Or a complex system involving software, hardware, people and organizations?
What is the difference between the newly coined terms of “geomatics” and “geo-automatics”? do they have the same meaning or are they different? Some of these questions have been answered clearly. Some of them raise more fundamental issues. Nevertheless, the common aim of all these discussions is spatial data and information.
Today, geo-informatics, geomatics and GIS are frequently applied, but they should be viewed in light of developments in creation and extraction of spatial data over the past three decades.
Khosro Khajeh (Translation)
Volume 3, Issue 11 , November 1994, , Pages 32-35
Abstract
Over the past twenty-eight years, the GIS computer technology has undergone tremendous changes and advancements along with software developments and variety of analytical methods, and also in terms of scope, quality of products and operating costs. These vast changes have been observed in recent research ...
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Over the past twenty-eight years, the GIS computer technology has undergone tremendous changes and advancements along with software developments and variety of analytical methods, and also in terms of scope, quality of products and operating costs. These vast changes have been observed in recent research studies, but what has so far remained unchanged and is possibly more important is that the next phase of GIS research and development should once again focus on the models and theoretical questions that always face us, and I would like to use my "framework" as a guide to deal with questions that need to be answered.
Khosro Khajeh (Translation)
Volume 3, Issue 10 , August 1994, , Pages 28-34
Abstract
Carl Steinitz, in his speech at the EGIS 93, describes the methodology of a project for outlook planning.
In 1990, after nearly twenty-five years of utilizing GIS in many projects, I came to the conclusion that there is a common structure for the continuation of this work, and in the October 1990 wrote ...
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Carl Steinitz, in his speech at the EGIS 93, describes the methodology of a project for outlook planning.
In 1990, after nearly twenty-five years of utilizing GIS in many projects, I came to the conclusion that there is a common structure for the continuation of this work, and in the October 1990 wrote a brief article entitled "A Framework for Theory" in the Outlook Journal, and this theoretical framework has become the main pattern of teaching and research in my projects in the last three years. In this article, I will try to present a brief description of this framework and show how it is used in a project.
As a teacher, I have always believed that we should be able to benefit from a comprehensive, integrated and adaptable approach when dealing with theory and practice. I do not accept and indeed reject the "up-to-down" theory of the approach or model of outlook planning which has universal application. Instead, I believe that an appropriate strategy is, first and foremost, a” perception”. My research for the underlying framework in which I organize this process has shown that there is a great deal of structural (and perhaps necessary) similarity among some of the questions raised by outlook planners and other environmental design experts.
Professor Amos Rapoport (University of Wisconsin) has described a useful definition for theories, models and frameworks. He briefly states: “A theory explains, a model predicts and organizes a framework; a framework can be judged based on its rationality and merit, but it has no claims against other frameworks.
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