Mansureh Malekian; Reza Ja'fari
Volume 20, Issue 80 , February 2012, , Pages 18-22
Abstract
Application of remote sensing data in identification of important areas in terms of biodiversity, prediction of the mechanism of the distribution of species and modeling the responses of biosphere communities to natural and human changes is one of the important issues in research. Environmental parameters ...
Read More
Application of remote sensing data in identification of important areas in terms of biodiversity, prediction of the mechanism of the distribution of species and modeling the responses of biosphere communities to natural and human changes is one of the important issues in research. Environmental parameters with certain bio-physical characteristics can indicate the mechanism of distribution and frequency of species at the surface of the land and explain how the habitat is occupied by species. New data from remote sensing technology have made it possible to combine them with ecological models to answer many questions about biodiversity. Recent advances in spatial and spectral resolution of sensors have made studying various aspects of biodiversity, such as identifying communities of species, estimating species richness, identifying climatic variables, and studying the habitat structure possible. In cases where direct recognition of a living creature is not possible, by using the indirect remote sensing approach, we can derive meaningful information from the bio-physical properties. This paper reviews the application of remote sensing in biodiversity and conservation studies, which involves the use of direct and indirect remote sensing in identifying species and communities, estimating species richness, identifying climatic variables and studying the habitat structure. Today, it is necessary to form increasing collaboration between remote sensing researchers and researchers in the field of biodiversity and conservation, so that steps can be taken towards better conservation goals.
Mohsen Hassanzade Shahraji; Ali Mohammadzadeh; Kurosh Khoshelham
Volume 20, Issue 80 , February 2012, , Pages 34-39
Abstract
In recent years, a new sensor called Lidar Continuous Wave has been introduced into the commercial laser scanners family. The main advantage of this new type of sensors is the complete recording of the return pulse after the collision with various ground features along the path of the laser pulse to ...
Read More
In recent years, a new sensor called Lidar Continuous Wave has been introduced into the commercial laser scanners family. The main advantage of this new type of sensors is the complete recording of the return pulse after the collision with various ground features along the path of the laser pulse to the surface of the ground. With full wave recording, the output of the cloud of points has a higher density and more reliability, along with new parameters, including pulse widths and pulse amplitudes for each point. These new parameters help us analyze and investigate outcomes of the three-dimensional cloud of points of these types of sensors ever more correct and comprehensive . Lidar's output can be applied in various fields, including updating 3D databases, extracting ground features, providing a 3D model of buildings, providing forest models, urban management and planning, traffic management, air pollution control, tourism industry, crisis management, and many other applications. In this article, we first discuss some points about the Lidar Continuous Wave sensor, the signal processing carried out on it so far, and how to extract the three-dimensional points from it. Examining different types of these sensors and a brief history of their evolutionary process forms the next section. In the end, various applications of this data in forest, urban and hydrographic fields are discussed.
Saeed Khodaeian; Parviz Ziaeian; Saeedeh Fakhari
Volume 19, Issue 74 , August 2010, , Pages 81-85
Abstract
One of the most important climatic parts of the heritage of the fourth era in the highlands of Iran is the glacial geomorphology and the effects of the glaciers of that period. The Damavand glaciers, with more than 15 small and large tabs with signs of life and activity, are the only survivors of those ...
Read More
One of the most important climatic parts of the heritage of the fourth era in the highlands of Iran is the glacial geomorphology and the effects of the glaciers of that period. The Damavand glaciers, with more than 15 small and large tabs with signs of life and activity, are the only survivors of those glaciers. Scattered studies have been conducted on these glaciers in recent centuries by Iranian and foreign scholars. However, a comprehensive report that describe and characterize the geomorphologic and morphodynamic characteristics of the glaciers in this region has not yet been compiled. In this paper, we try to interpret and analyze the shapes of glacier morphology, and to determine the extent and expansion of glaciers using remote sensing technology. The method of research is based on the fieldwork and the use of satellite imagery. The results show that the Damavand ice glacier is undergoing gradual shrinkage and melting under the influence of increasing temperature of the present age, and the existing ice cores are the remains of past glacial periods. The insignificant nutrition of glaciers through avalanches is not enough, but the effects and evidences of life are still evident.
Majid Vali Shari'at Panahi; Seyyed Rahim Moshiri; Alireza Este'laji; Shokrollah Mohammadi; Jamileh Fotouhi
Volume 19, Issue 73 , May 2010, , Pages 48-52
Abstract
The main purpose of this research is the importance of land use changes in Gorgan city using remote sensing data. In fact, remote sensing has vast applications in many fields of science and research. Possibility of regular periodic imaging and uninterrupted transmission of satellite images are two very ...
Read More
The main purpose of this research is the importance of land use changes in Gorgan city using remote sensing data. In fact, remote sensing has vast applications in many fields of science and research. Possibility of regular periodic imaging and uninterrupted transmission of satellite images are two very important factors in the use of satellite data. These advantages will help experts in diverse fields to be able to use satellite imagery and information in studies such as periodic variations in the Earth’s surface, changing features and phenomena and natural disasters. In fact, one of the essential needs of researchers, managers and planners is to have accurate and timely information. Land use maps represent human activities concerning exploitation of land, for example, industrial and residential areas, agricultural fields, and so on.
Mojtaba Fathi; Alireza Ma'manpush
Volume 18, Issue 72 , February 2010, , Pages 71-74
Abstract
Achieving stable agricultural production with proper profitability and, at the same time, preserving the environment from destructive effects of chemical fertilizers is not possible without taking the changes in farm’s soil and plant growth into account. The division of the farm into management ...
Read More
Achieving stable agricultural production with proper profitability and, at the same time, preserving the environment from destructive effects of chemical fertilizers is not possible without taking the changes in farm’s soil and plant growth into account. The division of the farm into management sections is carried out in a variety of ways. Concentrated sampling of plants and soil, preparation of contour line maps of its features, and the use of aerial (installed on airplanes) and satellite sensors are among these methods. In developing countries, access to high resolution satellite data is not feasible due to economic and security reasons. However, satellite data with smaller scale is partially able to make the division of the management sections in the farm according to the state of plant growth possible. In this study, the possibility of dividing in-farm management sections based on the NDVI index calculated from the reflection intensity at Landsat 7 satellite wavelengths has been investigated. The NDVI map provides the possibility of dividing farm sections, calculation of the cropping area of each product, and the division of sections with different growth. The coefficient of variation of the NDVI growth index in the 10 hectare farm scale was about 11.5% and was significant. The observable growth rate of the field and the growth rate estimated according to the NDVI index field show agreement.
Majid Danesh; Hosseinali Bahrami; Seyyed Kazem Alavipanah; Aliakbar Nowruzi
Volume 17, Issue 67 , October 2008, , Pages 26-34
Abstract
Soil texture and lime can be considered as amongst the most important soil characteristics, which are considered in many agricultural and environmental projects. Today, with the scientific progress and the advent of remote sensing technology, the possibility of exploiting this technology in soil science ...
Read More
Soil texture and lime can be considered as amongst the most important soil characteristics, which are considered in many agricultural and environmental projects. Today, with the scientific progress and the advent of remote sensing technology, the possibility of exploiting this technology in soil science has also been provided. In this study, for the analysis of soil texture and lime in the Pol Dokhtar area, the four-spectral data for September 7, 2007 prepared by IRS-P6 satellite with LISS III sensors were used. Geometric corrections and processes including UNC, SLED, NDVI, PCA, were performed on the main image. Finally, using randomized sampling method and based on PMU, FCC image of the region, 95 points were selected and samples were taken from two depths of 0-5 and 20-5 cm. Finally, using multiple regression, it was found that the lime and clay of samples at the first depth had a significant relationship with the near infrared band with modified R2 =0.73, and in the green band it was 0.72, and also at the second depth, with a red band of 0.54 and a green band of 0.48, of which all relationships were statistically significant at 1% statistical level. Consequently it was found that clay and lime have a significant effect on the spectral reflection from the soil surface in the region, and it is possible to study them in the region using satellite data and auxiliary data (incidental information).
Mohammad Hassan Nami
Volume 17, Issue 65 , May 2008, , Pages 20-22
Abstract
One of the most important inventions of humanity in the 20th century is the satellite, which is the fruit of many years of great efforts and the culmination of the technological advancement of mankind. With the development of satellites set in the orbit of the earth, it became possible to conduct high-altitude ...
Read More
One of the most important inventions of humanity in the 20th century is the satellite, which is the fruit of many years of great efforts and the culmination of the technological advancement of mankind. With the development of satellites set in the orbit of the earth, it became possible to conduct high-altitude imagery, independent of political boundaries. The development of electronic systems for the production of images and other imaging techniques, such as radar and infrared images, have caused many changes in remote sensing. Today, satellites provide experts with a wealth of various information about the planet. Today's age is called the Space Age, because spatial information is an integral part of today's life. Now the Space Contest is entering a new stage in order to gain information supremacy, and almost all countries that have enjoyed the taste of utilization of ultra-atmospheric space have been encouraged to build satellites with less expensive capabilities, and countries that do not benefit from this blessing have also made the achievement of this complex human-made phenomenon a priority.
Alirerza Sofianian; Samereh Falahatkar
Volume 17, Issue 68 , February 2008, , Pages 13-18
Abstract
Remote sensing and GIS are widely used in identifying and analyzing land use change. Satellite remote sensing provides multi-time and multi-spectral data that can be used to quantify the type and amount and position of land use change. Furthermore, the GIS also provides a flexible environment for displaying, ...
Read More
Remote sensing and GIS are widely used in identifying and analyzing land use change. Satellite remote sensing provides multi-time and multi-spectral data that can be used to quantify the type and amount and position of land use change. Furthermore, the GIS also provides a flexible environment for displaying, storing and analyzing the digital data needed to detect changes. Since environmental changes are important in order to give a general impression of the region's environment and build credible hypotheses based on sustainable development, detecting these changes is an important process in the monitoring and management of natural resources and urban development. Detection of changes is also considered as a part of modern science due to dependence on remote sensing sciences and GIS. With the rapid growth of cities in recent years, the recognition of their biophysical compounds and their dynamism is of particular importance and is considered as an important research topic. The operations that are carried out in the course of digital analysis and interpretation of satellite data and with the aim of identifying and distinguishing ground phenomena can be summarized in three stages of initial surveys and information preparation, classification of information and finalized reviews and processing. Geometric correction of images and their classification based on existing methods and algorithms, and the accuracy of production maps, and finally comparing the maps at different times are among the stages of detecting changes. In the present study, we try to describe the steps briefly.
Abbas Alimohammadi; Hadi Akbari
Volume 15, Issue 57 , May 2006, , Pages 30-33
Abstract
All phenomena in the universe are undergoing change and transformation. Certainly, we can say that there is no phenomenon on the planet that does not undergo metamorphosis. The difference between the phenomena in terms of change is the difference in the rate of change. In studies on land and natural ...
Read More
All phenomena in the universe are undergoing change and transformation. Certainly, we can say that there is no phenomenon on the planet that does not undergo metamorphosis. The difference between the phenomena in terms of change is the difference in the rate of change. In studies on land and natural resources, phenomena in general can be classified in terms of the rate of change into three categories: high speed (flood, earthquake, storm, climate change), average speed (land use, urban development) and slow (topographic changes, etc.) phenomena. Remote sensing has made it possible to study average and high speed changes. With the availability of images for two different times, changes can be assessed. In this regard, using images of the years 1988 and 1998 from the city of Tehran, changes in land use in this city have been retrieved and determined.
Mahdi Modiri
Volume 12, Issue 47 , November 2003, , Pages 2-6
Abstract
Remote sensing is important as a new technology for collection of geographic data for GIS on the one hand and as user's reference spatial data for scientific analysis on the other. In this paper, emphasis is placed on the importance of linking remote sensing raster data to GIS vector data to create IGIS. ...
Read More
Remote sensing is important as a new technology for collection of geographic data for GIS on the one hand and as user's reference spatial data for scientific analysis on the other. In this paper, emphasis is placed on the importance of linking remote sensing raster data to GIS vector data to create IGIS. The application of IGIS is of great value in a variety of applications, such as information classification and environmental modeling. It is evident that remote sensing and IGIS complement each other, and both progressed independently and separately, especially in the early days. With linking the technology, concepts and theories of both in IGIS, more advanced and up-to-date information systems can be created for use in real applications. Almost all projects that currently use satellite data or deal with environmental data benefit from development of IGIS.
