What are Remote Sensors ?
Remote sensing and Remote control technology sounds too good when you think of Handling any electronic device sitting far away from it. The innovative technology of remote signal processing and remote sensing ruling the entire universe because not only you know about controlling a T.V set, a Drone, or a Toy Helicopter with your Remote or Joystick but you also hear about the propagation of Rockets and Missiles which are intended not only to reach very great distances but they are required to follow precise flight paths and altitudes to reach the exact location.
You may take interest in knowing, how any remote control device works whether that device is your T.V set or that complicated task of placing a Satellite in Intended Deep Space, or it the Dangerous step to hit the Enemies shelter with a Missile sitting just from the control Laboratories.
The working principles of remote control become similar in each and every system but the propagation medium and propagating signals vary system to system.
If You think of your T.V Remote then the propagating medium is air and the signal is transmitted in the form of infrared light pulses which is further detected by your T.V receiver and the specific light pulse gives specific instruction to your T.V set.
I hope you know the ways in which a drone can be controlled. Modern drones come with WI-FI Receivers which can be controlled with your smartphones Like Air-Conditioners and various internet of things.
The complexity is felt when the distances become fairly high. If you think of that Robotic Rover which was sent to the surface of Mars by NASA on August 5 2012 which was 225 million kilometers away from the earth then transmission of Radio signal and the process of Demodulation and implementation of that signal to control the Rover really becomes a complex task.
For fun, I think I should share a real funny thing which will make your mind to do some mathematical calculations. The Robotic rover, "Curiosity" which was sent to Mars used to take 14 minutes to receive the Radio signal from the earth station and another 14 minutes for Re-transmitting it to the Earth, I mean to the Rover engineers and the Scientists of NASA.
The Remote Control System is mostly based on Electromagnetic signal processing, the circuit design for transmitters and receivers for transmission of that signal and then various processes of signal processing like modulation demodulation, Noise filtration through various filters is accomplished to make that signal safe enough to transmit it to open sky.
Security is the main concern of every field of science and technology and so in the field of Remote control to protect the system from unauthorized access the priority is given to the security Specialist. The matter is not only of unauthorized access but also for self-defense if the system of remote sensing is particularly related to Missiles technology.
Another Issue is also Related To Data Protection Because various Space Organisations Like Indian Space Research Organisation(ISRO) Or National Aeronautics and Space Administration(NASA) usually Use Electromagnetic Waves to Receive Data From their Satellites Placed In the Space, Which Might Be Confidential and Should not Be Received by Any Other Organisation, So They Use unique Highly-secret Frequency Bands to Hide The signal From the Sharp signal Detectors of other Organisations.
In the Case Of Missiles, The Used Singal Frequency Band for remote control I mean for giving Instruction to the Missile is Also Kept Secret To Protect The Missile From Jamming because If The Frequency Band is Known then Jamming of that Particular frequency band Is not A Complex Task.
Finally, you Will Love To Read some Useful Books For Remote Control Based On Radio Signal Transmission. Personally, I use To read A book Named Radio Remote-Control and Telemetry and their Applications To Missiles and I Recommend You to Learn It to Know the Various Scientific Terms and Electronic Circuits For Remote Control Which Is used In The real Systems Of Innovative World. I Still Feel A lot Of Problems While Reading This Book But Hope You Will Find This Free eBook One of the Most Helping One in The Field of Remote Control.