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A simple technique for classifications of earth resources using DOPD silion

V. K. Farkua
Department of postgraduate studies and Research in
Physics, R.D University, Jabalpur -482001 India


Abstract
In this work a technique for differentiating of different earth resources -ground, grass, stone, water bodies, crops etc have been described. The emitter and collector terminals of a transistor BC 107 were coupled to a simple oscillator and amplifier circuit The top of such a transistor was cut, so that and amplifier silicon material is capable of exposure to different intensities obtained from earth resources through reflection from them, The hetum- different resources beam, infrared and visible wavelengths were reflected from different resources .The results obtained through the circuit were analyzed.

Introduction
Remote sensing implies sensing from a distance. It obtains information about objects or phenomena by a scientific device I allied sensors without any physical contact between the objects l phenomenon and the sensing device, The most modern and widely used remote sensing techniques are based, on detection or sensing f electromagnetic radiations. The gamma rays, X-rays, ultra-vamped, visible rays infrared microwaves and radio waves form the electromagnetic spectrum in ascending order of their wavelengths and all these travel with the speed of light which is 300,000 Km sec The remote sensing in particular refers to the sensing or detection of electromagnetic radiations which are reflected, scattered or emitted but an object, Consequently remote sensing techniques are based on the sensors capable of detecting and measuring the reflected, scattered or emitted radiations in the modern remote sensing, techniques the scope of utilization of the electromagnetic spectrum to a wider range has been developed so that not only of visible but non visible electromagnetic spectrum and its interaction with matter is converted into interpretable information with matter is converted into interpretable information .hence human visibility has been extended to the no visible part of the electromagnetic spectrum too. Thus these days visible, infrared and microwave regions of the electromagnetic spectrum are being used in remote sensing for inventorying .mapping and monitoring earth resources /1,2/.

In the remote sensing technique used for earth resources surveys .the reorganization and classification of objects. in based on their characteristic electromagnetic signatures. In fact all earth materials have characteristic spectral signatures. Hence the reflections are different from different materials. This reflection when falls on doted silicon produces some voltage which when amplified and detected responds to a particular earth resource. Consequently. Classification of earth resources can be done in a laboratory by this simple electronic circuit,

Experimental Technique
A transistor BC 107 was taken, it was cut at its top, so that the silicon material inside its capsule is capable of? ….




Exposure (fig 1 ). The base terminal was not used and the emitter collector terminals were connected to an amplifying circuit Hooked with an oscillator. Finally the circuit ends in a loud speaker capable of producing audio vibrations. An accurate digital meter was connected to measure the output of the circuit before it is fed to the loud speaker. Thus a millimeters and a loud speaker both serves as detectors (Fig 2 and Fig 3). He-Ne Laser light was allowed to fall on one of the ground resources say grass, the reflections from this grass were made incident on the doped silicon of the transistor through a reflector mirror. The output was measured by a digital meter; similarly vibrations were heard from the loud speaker to the experiment was repe\ated with different wavelengths including visible and infrared for different earth resource materials. It is observed that the sensing response is different for different resources /3,4/.

Results and Discussions
The measurements of output voltage and sound intensity variation give indication for a particular earth resource. Different resources give different output voltages and sounds. This is evident from the sensing properties of doped silicon. It is observed that the infrared response is better in some earth resources. Thus the classification of earth resources can be done in a laboratory for different earth resources using doped silicon. In addition the experiments were performed with other transistors of the series, namely BC 108 and BC 109. Experimentally it has been confirmed that the detection of different earth resources can be done equally well with these transistors too. This is encouraging and offers a simple technique for studies on remote sensing even in a small laboratory. Further this also serves a demonstration method of the phenomenon of remote sensing in a class room /5/

Acknowledgement
Author is thankful to Council of Scientific and Industrial Research, New Delhi for sanction of financial grant under a scheme CSIR 8(31)/(85) EMR-II

References
  1. V. K. Farkya, Remote sensing Applications, Science and Society, Vani Eduational Publishers, India, P. 53 (1985)

  2. A. J. Dekker, Electrical Engineering Material, Prentice-Hall of India, New Delhi, P. 176 (1969).

  3. Pietritz Richard D. L., Fundamentals of Infrared Detectors, IEEE 47, 1458 (1966).

  4. Putley E.H./, Solid State for Inffrared detection J. Sc. Instr. 43, 865 (1966)

  5. V. K. Farkya, Rekha Agrawal and Rubeena Saheen , On Properties of detector silicon, Microelectronics Yugoslavis (1989)