Habarlak K. S., Olynovych J. N., Bondar O. E.

Oles Honchar Dnipropetrovsk National University

VIRTUAL EXPLORATION OF THE DOPPLER EFFECTON EARTH AND IN SPACE

The purpose of this scientific work is to explore the Doppler Effect, firstly, on Earth, in medicine, and to develop a program that will process exploration’s data and will provide you with a possibility to study this effect, secondly, in space, in Global Positioning System, and create a program that will visualize this system’s work.

In the first part, the Doppler Effect basics have been stated. The Doppler Effect is a change in frequency of a wave for an observer moving relative to its source. The way in which the Doppler Effect is used in medical ultrasound devices, the diagnostic possibilities in medicine, and future achievements based on this effect have been analyzed. The exploration with ultrasound alone gives a black and white image, in which it is very difficult to understand if there is a stenosis or occlusion in patient’s vessel. Having applied the Doppler Effect, blood flow’s colorful visualization is shown, which gives a better insight into the existing problem.

Nowadays the Doppler ultrasound examination is one of the safest ways to diagnose cardiovascular system’s illnesses. Thanks to Doppler ultrasound, millions of people had an operation on time and were able to continue their immersive life without any restrictions. That is why Doppler ultrasound devices are rapidly evolving, becoming more and more mature every day. Therefore, it is evident, that more methods of explorations associated with the Doppler Effect are developing.

An easy-to-use program has been developed. Thanks to it, doctors after having examined a patient can now easily store and handle all the gathered information, visualize problematic places in legs’ vessels, moreover, after pressing a single button get a diagnosis. In addition, another program was developed. This one is a 3D model of lower extremities’ vessels, now available to anyone. After clicking on any part of a vessel, the program will mark this part and show its name.

In the second part, the structure of Global Positioning System has been described. In the modern world, almost everyone uses this system. However, almost no one knows that the technology behind GPS is based on the Doppler Effect. This system has 24 satellites orbiting around the Earth at a constant speed. Thanks to on-the-ground stations, every satellite knows its precise position in space and time. Any device like a smartphone needs to solve an equation to get its position. Only considering the Doppler Effect and clock bias, a device can calculate current satellite’s position, solve the equation and pinpoint its own position.

A 3D model of a GPS has been created. There you can see all 24 precisely modelled satellites rotating on their orbits around the Earth and better understand how this system works. In addition, you can toggle orbit visibility and zoom it on a satellite in order to examine it better.

All applications are easy to understand and can be used in astronomy and physics classes, by students while studying the Doppler Effect and by doctors to simplify data processing.