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Showing posts from February, 2020

GIS Jobs- New Openings

GIS based vacancy in Autoplant System, India for beginners in GIS field.
Looking for Expert in GIS based vacancy in Sathi Planners, West Bengal with moderate experience in GIS field.
Vacancy of Executives in GIS in AGRIBAZAR, Uttar Pradesh for beginners in GIS Field.
Analyst Trainee required in GIS based vacancy with programming background, InfoCorporate Service, Maharashtra for beginners in GIS field.
Engineerrequired in GIS based vacancy in Stratify Business Solutions, Karnatka for beginners in GIS field.
Project Manager required in GIS based vacancy in AllGeo Solutions, Uttar Pradesh with moderate experience in GIS field.
Technical Support based vacancy in GIS field in Scanpoint Geomatics Ltdfor beginners as well as moderate experience in GIS field.
Executives in GIS based vacancy in Vector Head Info Solutions, Hyderabad beginners as well as moderate experience in GIS field.
Specialist in GIS based vacancy in Pinnacle Infotech Solutions, Jaipur, with moderate experience in GIS field.
Specia…

REFLECTANCE, SPECTRAL SIGNATURE AND ITS CURVE

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This article is prepared to understand the role of reflectance and spectral signature in a satellite image. How the reflectance vary with change in EMR and characteristics of earthsurface feature.
It is very important to understand that how the reflection which is received by sensor, converts into an image. It is explained in earlier article that how the reflectance taking place and its behavior of incident energy after interaction with surface. The reflectance completely depends on incident energy and characteristics of material/earth’s surface feature. So reflectance which is created during this process is called SIGNATURE.
Every object on the earth surface reflects and emits incident radiation is defined as signature of that object. It can be also called re-radiation from earth surface feature. These signatures are recorded by sensor boarded on satellites. As it is understood that basically only three natural land covers, it includes vegetation, soil and water. So behavior of these …

EMR Interaction with Earth Surface Features

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In this article discuss the interaction of Electro-Magnetic Radiation (EMR) with earth surface features. After passing through atmosphere, the EMR reached to earth and as already discussed EMR which have least or almost nointeraction with atmosphere is used by remote sensing sensors. This part of spectrum is called atmospheric windows, which have zero or no interaction with atmosphere. 
When EMR reached and interact with earth’s feature, three things take place with incident energy. ReflectionAbsorptionTransmissionWhen EMR is incident on any earth feature then part of it, as shown in figure ReflectedAbsorbedTransmitted Figure showing Interaction of sun energy (EMR) with Earth Surface Features
Estimated radiation states that sum of these energies (reflected, absorbed and transmitted) is equal to incidental energy on earth’s feature.
How much amount will be reflected or absorbed or transmitted depends upon material to material as well as many other conditions. These quantities are sometimes ex…

Atmospheric Interaction of Electro-Magnetic Radiation

Remote sensing process depends on source of energy, it can be natural in the form of sun to illuminate object. Sun light has to pass many obstacle before reaching and interaction with object. This obstacle can be atmosphere, which absorb or scatter sun light at different wavelengths.  
The quality of satellite image may affected by these obstacles and quality for correct interpretationand accurateclassification, one need to improve satellite images by enhancement process.
Electro-Magnetic Radiation (EMR) propagates through the Earth’s atmosphere, however atmosphere may influence

   Speed of radiation   Wavelength   Intensity   Spectral Distribution   Change in Direction due to refraction So EMR may refracted, scattered and absorbed by atmosphere before reaching to ground/Earth's surface Refraction-Refraction may take place, when EMR come across substances of different density, like air and water. Refraction is bending of light when it passes through one medium to another medium. Refrac…

Latest GIS and Remote Sensing Jobs

New GIS and RS Jobs Openings
Job Title: GIS Analyst/GIS Technician Company Name: AllGeo Solutions Experience:  3-5 years  Location: Allahabad, Uttar Pradesh
Job Title: GIS EngineerCompany Name: Knowledge Spatial Private Limited - Experience: 1 year   Location: Gurgaon, Haryana
Job Title: GIS EngineerCompany Name: Budowa Infratech Pvt Ltd - Experience:  1 year Location: Ghaziabad, Uttar Pradesh
Job Title: GIS EngineerCompany Name: Global Innovative Technical Solutions Pvt Ltd – Experience: 1-2 years   Location: Bengaluru, Karnataka
Job Title: GIS ExpertCompany Name: Sathi Planners Experience: 3+ years   Location: India
Job Title: Junior GIS EngineerCompany Name: MicroITG Experience: 0-6 Months   Location: Bokaro, Jharkhand
Job Title: GIS Engineer InternshipCompany Name: Edgemap Softwares Experience: 0-2 years Location: India
Job Title: GIS Analytics InternshipCompany Name: ElevenX Consultancy Private Limited - Experience: --

Height Measurement by Aerial Photographs based on Concept of Parallax

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There are several methods through which height/elevation can be measured using satellite image and aerial photographs. In case of satellite image such as, Cartosat,  ASTER, Worldview I & II and others are used to create height or elevation data in the form of digital elevation model. Aerial photography, LiDAR mapping are very common for creation of elevation data on higher scale/resolution for detailed study.  In the last article, relief displacement used to measure height of any object on earth surface. Here in this another method will be discussed to measure height of any given object on the earth surface. Parallax for Height Measurement using Aerial PhotographyParallax ConceptPhotogrammetry is capable of measuring elevation of earth surface. Aerial photographs/stereo pair satellite images can be used to measure elevation differences through the use of parallax method. New launched satellite are providing stereo pair satellite images images such worldview-2 etc.
Parallax can be def…

Aerial Photographs to Measure the Object Height

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Satellite image and aerial photographs are very important for mapping and creation of spatial data. As well as these aerial photographs and satellite images can be used to create elevation data. Different methods employed for height measurement for a single given spot/location and also creation of digital elevation model.
Therefore, in this article discuss about displacement in aerial photograph occurred due to relief or height of object on ground.
Relief/Height/Elevation is the most significant source of image displacement. When point/object on the photograph is displaced from its datum position because of its elevation, a displacement take place so this displacement is called Relief displacement or displacement due to height of object.
This relief displacement process can also help to calculate the height of object. This relief displacement is explained by below figure. In this Figure, ‘O’ is the camera station. ‘NA' is a flat plain on which stands a tower ‘AB’ with its base at ‘B’