What is vidicon used for?
A vidicon is a television camera tube that formed an image by focusing light onto a photoconductive faceplate. An electron beam scanned the faceplate, detecting light intensity for each scan line.
What is vidicon television camera?
The vidicon is a storage-type camera tube in which a charge-density pattern is formed by the imaged scene radiation on a photoconductive surface which is then scanned by a beam of low-velocity electrons. The fluctuating voltage coupled out to a video amplifier can be used to reproduce the scene being imaged.
Why does a Colour camera have four vidicon tubes?
In addition to allowing the registration accuracy between the colour images to be relaxed, the 4-tube camera allows additional mis-registration of these three images relative to the luminance image.
What is return beam vidicon?
The Return-Beam Vidicon (RBV) instrument was flown on board the Landsat-1 to 3 satellites, between 1972 and 1983. It consisted of three co-aligned television cameras, one for each spectral band (band 1: blue-green, band 2: yellow-red, band 3: NIR).
How video signal is developed in vidicon tube?
As the electron beam from the gun is incident on the charge image, drop in voltage takes place. As a result, a varying current is produced. This current produces the video-signal output of the camera.
What is Landsat remote sensing?
Landsat represents the world’s longest continuously acquired collection of space-based moderate-resolution land remote sensing data. Landsat is an essential capability that enables the U.S. Department of the Interior to wisely manage Federal lands.
What is image Orthicon?
: a camera tube that is similar to the iconoscope or the orthicon and uses secondary emission and electron multiplication to produce the voltages that are subsequently amplified and transmitted as television-picture signals.
What data does Landsat collect?
Landsat shows us Earth from space. Since the first Landsat satellite launched in 1972, the mission has collected data on the forests, farms, urban areas and freshwater of our home planet, generating the longest continuous record of its kind.
How do Landsat satellites work?
As a Landsat satellite revolves around the Earth, its sensor “sees” a certain portion of the Earth’s surface. As the satellite orbits the Earth from pole to pole, it appears to move from east to west because of the Earth’s rotation. This apparent movement allows the satellite to view a new area with each orbit.
What is Liss IV?
LISS-4 is a high-resolution multi-spectral camera with three spectral bands and having a resolution of 5.8m and swath of 23Km from 817 Km altitude. The panchromatic mode provides a swath of 70Km and 5-day revisit.
How Landsat images are made?
Landsat scenes are made up of these 30-meter squares, or pixels. The pathway of light used by Landsat: from Sun to ground, then reflected to Landsat, then transmitted to relay stations and sent to computers for analysis. Landsat 7 observes the Earth in 7 ranges (or bands) of the electromagnetic spectrum.
What is LISS III data?
Linear Imaging Self-Scanning Sensor 3- LISS III is a remote sensing satellite camera from ISRO, India. The LISS – III camera provides multispectral data in 4 bands. The spatial resolution for visible (two bands) and near infrared (one band) is 23.5 meters with a ground swath of 141 kms.
What is a vidicon tube?
A vidicon tube is a video camera tube design in which the target material is a photoconductor. The vidicon was developed in the 1950s at RCA by P. K. Weimer, S. V. Forgue and R. R. Goodrich as a simple alternative to the structurally and electrically complex image orthicon.
What is the history of Vidicon?
The vidicon was developed in the 1950s at RCA by P. K. Weimer, S. V. Forgue and R. R. Goodrich as a simple alternative to the structurally and electrically complex image orthicon. While the initial photoconductor used was selenium, other targets—including silicon diode arrays—have been used. Schematic of vidicon tube.
What is photoconductivity of Vidicon?
Photoconductivity is the basis of working of a Vidicon. We all know that photo means light and so photoconductivity is the property that shows the variation in conductivity of any material with the change in intensity of light falling on that surface.
What is the life span of a vidicon?
The tube length is around 12 to 20 cm with a diameter of 1.5 to 4 cm. Due to small size and easily operational characteristic, at the time of development, they became highly popular. Around 5000 to 20, 000 hours is generally considered as the estimated life span of Vidicon. Photoconductivity is the basis of working of a Vidicon.