Wednesday, October 29, 2008

IRS MISSIONS

Indian Remote Sensing satellite
Indian Remote Sensing satellites (IRS) are a series of Earth Observation satellites, mostly built, launched and maintained by Indian Space Research Organization of India as part of the Indian space program. The IRS series provides remote sensing services to the country.
1. The IRS system
Following the successful demonstration flights of Bhaskara 1 and Bhaskara 2 satellites launched in 1979 and 1981, respectively, India began to develop indigenous IRS (Indian Remote Sensing Satellite) program to support the national economy in the areas of agriculture, water resources, forestry and ecology, geology, water sheds, marine fisheries and coastal management. Later India established the National Natural Resources Management System (NNRMS) for which the Department of Space (DOS) is the nodal agency, providing operational remote sensing data services. Data from the IRS satellites is received and disseminated by several countries all over the world. With the advent of high resolution satellites new applications in the areas of urban sprawl, infrastructure planning and other large scale applications for mapping have been initiated.
The Indian Remote Sensing Satellite system is the largest constellation of remote sensing satellites for civilian use in operation today in the world. With the launch of CARTOSAT-2A, the constellation now has eight satellites in operation – IRS-1D, OCEANSAT-1, Technology Experiment Satellite (TES), RESOURCESAT-1, CARTOSAT-1, CARTOSAT-2 and the latest CARTOSAT-2A and IMS-1. All these are placed in polar sun-synchronous orbit and provide data in a variety of spatial, spectral and temporal resolutions to enable several applications to be undertaken relevant to the national development.
2. IRS data applications
Data from Indian Remote Sensing satellites are used for various applications of resources survey and management under the National Natural Resources Management System (NNRMS). Following is the list of those applications:
Preharvest crop area and production estimation of major crops.
Drought monitoring and assessment based on vegetation condition.
Flood risk zone mapping and flood damage assessment.
Hydro-geomorphological maps for locating underground water resources for drilling well.
Irrigation command area status monitoring
Snow-melt run-off estimates for planning water use in downstream projects
Land use and land cover mapping
Urban planning
Forest survey
Wetland mapping
Environmental impact analysis
Mineral Prospecting
Coastal studies
Integrated Mission for Sustainable Development (initiated in 1992) for generating locale-specific prescriptions for integrated land and water resources development in 174 districts.

Sunday, October 26, 2008

Introduction of Remote sensing

Introduction
Remote sensing can be defined as the collection of data about an object from a distance. Humans and many other types of animals accomplish this task with aid of eyes or by the sense of smell or hearing. Geographers use the technique of remote sensing to monitor or measure phenomena found in the Earth's lithosphere, biosphere, hydrosphere, and atmosphere. Remote sensing of the environment by geographers is usually done with the help of mechanical devices known as remote sensors. These gadgets have a greatly improved ability to receive and record information about an object without any physical contact. Often, these sensors are positioned away from the object of interest by using helicopters, planes, and satellites. Most sensing devices record information about an object by measuring an object's transmission of electromagnetic energy from reflecting and radiating surfaces.
Remote sensing imagery has many applications in mapping land-use and cover, agriculture, soils mapping, forestry, city planning, archaeological investigations, military observation, and geomorphological surveying, among other uses. For example, foresters use aerial photographs for preparing forest cover maps, locating possible access roads, and measuring quantities of trees harvested. Specialized photography using color infrared film has also been used to detect disease and insect damage in forest trees.
The simplest form of remote sensing uses photographic cameras to record information from visible or near infrared wavelengths (Table 2e-1). In the late 1800s, cameras were positioned above the Earth's surface in balloons or kites to take oblique aerial photographs of the landscape. During World War I, aerial photography played an important role in gathering information about the position and movements of enemy troops. These photographs were often taken from airplanes. After the war, civilian use of aerial photography from airplanes began with the systematic vertical imaging of large areas of Canada, the United States, and Europe. Many of these images were used to construct topographic and other types of reference maps of the natural and human-made features found on the Earth's surface.

What do the initials 'GIS' stand for?

Geographical Information System.