Radio Audience Measurement Research
ABSTRACT
Radio and Television have been traditional form of mass communication for years; they have been instrumental for information, entertainment and education.
They encircle development, information shared through these medium present what will be necessary for present or future development. Over the years, it has become necessary to know the average number of listeners or viewers onto a radio or TV show; this is important for advertising and marketing; ratings and promotions; influence and growth and many other purpose. There are certain technologies used in knowing this, others have been through poll taking audience measurement, there are also estimation based on feedback, these have been effective in the way they come. This research paper presents a technology that will be used to detect the number of people tuned in to a radio station at any given time. Since radio waves are broadcasted from transmitting antennas of radio stations with an amount of power (in watts) and frequency (in Hertz), the effective power radiated can be calculated. This value, the gain and radiation intensity can lead to a measurement of maximum reach of the radio waves in different directions. Since these waves are spread out in all direction, there are imaginary lines of propagation which can be detected by a new antenna design of this research posits. These waves get intercepted by radio receivers while tuned to a station. This will detect the number of devices tuned in at anytime, and will also detect the number of devices intercepting the radio waves from that area. This research is important and it is only the beginning of what may extend to all forms of radio waves propagation.
1.0 INTRODUCTION
A radio wave receiver or radio set is a device which detects the power generated in an antenna, and transforms it into useable form. [1] It detects, demodulates and amplifies signals transmitted. In the phenomenon of waves in physics, there is what is known as radio waves, radio waves are electromagnetic waves of wavelength range 0.5cm – 30,000m; it is radio waves that radio set receives.
Electromagnetic waves are waves that have electrical and magnetic field components, these fields are usually in phase, perpendicular to each other and travel at the speed of light. [2] They are classified using frequency and wavelength, the classification is given as a spectrum where frequency increases and wavelength decreases.
Radio waves can be reflected when they hit a surface; they can also be bent or refracted to another direction when they travel from one medium to another. They exhibit other characteristics of electromagnetic waves such as scattering, absorption, diffraction and polarization.
When radio waves hit a surface along its direction of propagation, the nature of the surface will determine if its energy will be absorbed or reflected, this casts a shadow beyond the surface or material and some radio wave energy does not enter the shadow area, they are said to be diffracted in what is called diffraction.[1]
When radio waves are aligned in the direction of electric component of the electromagnetic field, they are said to be polarised with respect to the direction, the process is called polarisation. Radio waves are continuous waves and are attenuated with further distance.
In a broadcast station, there are processes that take place using available equipments for radio signals to be ‘created’ and sent to be received by devices anywhere within the reach of the transmitting power and frequency of the radio waves.
Radio transmitter, antenna, amplifier and mast, are part of radio waves broadcast equipments available in broadcast stations. Radio transmitter is an electronic device that generates and sends radio waves together with an antenna. An amplifier or more specifically a power amplifier increases the power of the signal thereby increasing the reach of the radio waves.
Effective radiated power can be used to calculate the coverage of the radio station or simply the reach of the radio waves. So there is a region of radio wave termination or fade off. With that information available to ‘a new kind of’ transmitting antenna, this research will help detect all radio waves that are ‘intercepted’ or received by devices within the coverage area not reaching the coverage ‘boundary or termination point’ and note the numbers to have a count.
2.0 THEORETICAL DEVELOPMENT
2.1 Radio Wave Broadcasting
Radio waves broadcasting will be described under this heading in transmitting and receiving pattern. Sound from the microphone as information is converted and sent to the transmitter as electronic signal. The electronic signal is sent as sine wave produced from changing electric fields between two points. [3]
Sine waves of constant amplitude of the radio frequency signal are generated from the oscillator circuit of the transmitter; these sine waves are called the carrier waves. They are added in the transmitter modulator circuit with the electronic (or say information) signal from the microphone. This addition can be done by altering the amplitude (or strength) of the radio frequency signal, or by altering the frequency. [3]
Wave amplitude of the electronic signal is change between two points of high and low value; this can be voltage a parameter of changing electric current. Wave frequency is the number of times a sine wave cycle is completed in one second; that is the number of cycles per second. [3]
The process of adding the information signal to the carrier wave is called modulation; when amplitude is varied on addition, it is called Amplitude Modulation (AM), and Frequency Modulation (FM) when frequency is varied on addition. [3]
The transmitter output is a high frequency wave that is sent through a co-axial cable to the transmitting antenna, this move through the cable as pulsating electric field, the end of the cable is bent at right angles. What is obtainable is that the cable enters the radiating element and between its poles and the waves is diffracted as they are spread out. This mode of operation is with dipole antennas [4]
A simple of this whole process is that transmitter combines the carrier wave with the audio signal, sends to the antenna, and the antenna beam these waves out in all directions in form of lobes with more to a direction than others.
Radio stations are assigned frequency band for transmission to make them available when a radio receiver is tuned in that frequency, in some countries, same band can be given to the same radio station, but are told to have radiation intensity in different direction to avoid interference at the same direction.
An antenna is designed to radiate efficiently with directional and polarisation properties and the radiation is produced by accelerated or decelerated charges, so these antennas do not produces what they radiated, they are the medium for radiation. Antennas can be for transmission or reception.
Radio devices or radio receiving set usually have antenna and are graduated to pick audio signals sent as radio waves from broadcasting stations. So the antenna of a radio set intercepts radio waves, built in circuitry of the radio set helps to convert received signal to voltage which is later converted to sound.
Radio receivers usually have tuner to tune into the frequency which a desired radio station propagates. Since there are radio stations propagating radio waves in all directions, the tuner filters out all radio waves except that which the listener is to; the tuner is a variable capacitor.
The capacitor and inductor of a radio resonates at a particular frequency at a time, the resonator of a radio helps to amplify radio waves that matches the frequency the radio is tuned to. When the tuner is adjusted, it changes the resonant frequency of the resonator and also changes frequency of the ‘new’ radio waves the resonator amplifies.
Radio waves after striking the antenna, spur a tiny alternating voltage in the radio set, the frequency of this alternating voltage is same with that of the radio waves received. Radio waves oscillate, and the radio circuit oscillates, when everything is in sync, they are resonant.
The resonator and tuner can also be termed electronic filters when defined in some other terms. Information or sound from a microphone as described above is encoded as information signal, when the information signal is passed to the transmitter; it is combined with a carrier wave in a process called modulation. Part of the functions of radio circuitry is to demodulate and decode signals.
Radio receiving circuitry are available in many devices; TV, mobile phones and some other electronics, the mode of operation is same and some are built to overcome possible effects because of the sort of devices they come with; Noise and linearity are considered for in building some.
Radio receivers are evolving in design, delivery and capacity, there are the high definition radio whose radio frequency is broadcast in binary form and the receivers have digital tuner to match and pick those signals. This kind of broadcast provides further information in text format, maybe news, lyrics, weather and program list for that day.
Radio communication is instrumental to our lives and our environment, it will ever evolve.
3.0 EXPERIMENTAL ANALYSIS
This research centers on having sophisticated transmitting antennas; work with receiving antennas is less needed since radio devices are so much and some of their mode of operation supports this research. This research will help determine the number of listeners to a radio station at any time, using ‘wave-reach’ knowledge.
‘Wave-reach’ uses directivity, intensity and gain of the antenna to know the maximum distance of transmitted waves from FM broadcast stations in different directions. The antenna will be built with certain semiconductor sensor which with this is programmed to note lobes of radio waves propagated and what happens to them; for example: interception by receiving antenna, attenuation, absorption, interference and many others.
With this known and determined, ‘set of waves’ that are intercepted by receiving antennas are noted, those attenuated at the maximum distance of reach of the waves are not reported since this is expected, those that are absorbed are also noted.
Transmitting antennas are part of the transmission system of broadcasting, waves sent to them are sent out in different directions; these waves go as large beam of waves called lobes. Lobes are classified according to their position if placed on a circular hemisphere; the biggest appearing long and wide is the major lobe, minor lobes are not as long and wide compared with major lobes, side lobes are smaller and back lobe is on the opposite, relative to the major lobe.
Within these lobes, there are ‘lines’ of propagation; as waves spread out in their number, they do in a ‘regular’ format. These imaginary lines of propagation are many; some as set of lines, in reception, absorption or attenuation. The transmitting antenna in this research will note the number set of radio wave lines that are onto receivers.
Reception antennas therefore intercept ‘lines’ of radio waves from various transmitting stations; its tuner circuit ensure that the desired radio station is available by tuning to the frequency; the resonator amplifies oscillations within that particular frequency band, while reducing oscillations at other frequency outside the band the circuit of the receiving set amplifies.
This lead to so many questions but what seem obvious is that ‘lines’ of waves received by a reception antenna tuned to a particular station maybe more than that of other waves, which may increase detection at the transmitting antenna and that will be a noted or counted by a system that the sensor reports to.
3.1 New Transmission Antenna
3.2 Reception Antenna described
4.0 Results and Discussion
4.1 Conclusion
Glossary
Acknowledgement
References
1. Bowditch,N, (2005), Chapter 10, Radio Waves; the American Practical Navigator. Prepared and Published by National Imagery and Mapping Agency
2. Wackeroth, D (2005) Electromagnetism, Phy102A
3. Yerkes Summer Institute, (2002), Radio Waves Basics, Center for Cosmological Physics
4. Kathrein Basic Principles for Mobile Communication
Bibliography
About the Author
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MadgeTech radio frequency receiver with USB cable $249.00 Wireless datalogger/transmitter combines the features of a standard datalogger with the convenience of a wireless transmitter. Compact, portable design means the device can be installed just about anywhere. Massive internal memory can record up to 13,107 pH and temperature measurements. Start/stop times and sampling intervals are user configurable making the device flexible to your needs. Data may… |
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