VLF SID monitor is a very-low-frequency (VLF) sudden-ionospheric-disturbance monitor. It is a radio receiver operating in the frequency range of 3kHz to 30kHz VLF band of the electromagnetic spectrum. Most broadcast receivers give out voice or music output, or digital data for modern-day communication receivers, whereas VLF SID monitors do not. These receive man-made or natural radio signals in VLF band. Here, there is no demodulation or extraction of data or voice contents—the receiver simply provides a calibrated DC voltage output as a function of input RF signal strength.
This receiver finds application in remote sensing and scientific studies related to the ionosphere. Ionosphere is a result of ionisation of Earth’s upper atmosphere, primarily due to the Sun and solar radiations. VLF radio/electromagnetic signals travel and propagate around the globe using Earth-ionosphere waveguide mode. Any changes to the ionosphere due to intense solar activities such as solar wind and bursts, coronal mass ejections (CMEs), solar X-ray bursts disturb the quiet-day ionospheric conditions, which affect the propagation of radio waves in general and VLF radio waves in particular. Therefore such changes directly affect the signal attenuation of VLF signals. Thus, output from VLF SID monitor is a direct indication of such ionospheric disturbances and, hence, solar activity.
Waichal Research is working on the research and development of different technologies. The company has developed customised innovative prototypes for industrial startups and offers technology transfer on a commercial basis. Prasanna Waichal, director and chief scientist, Waichal Research, says, “We do not want to restrict ourselves to any specific field or area of engineering or sciences; rather we want to cultivate the culture to have expertise in mixed domains. We want to develop newer technologies for the future and contribute to the existing technologies for the betterment of our lives to develop a sustainable society, the nation and mankind at large.
“We actively take part and work closely with academia in providing industrial training to students, who are the future workforce of the society, and also contribute to research activities by developing specialised electronics, instrumentation, process controllers and product prototypes for academic researchers, both staff and students.”
VLF SID monitor is completely designed, developed and manufactured in India with years of efforts in designing and successful field trials. What makes it unique is that it is designed to meet industry standards, yet provides affordable solutions to researchers in India and abroad in an easy-to-use or plug-and-play fashion. Scientific research groups, universities and academic institutions involved in the study of space-weather, solar-terrestrial physics, radio and ionospheric wave propagation from all over the world require such setups.