Between Space and Earth: A Researcher’s Journey to the Ionosphere
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Looking up at the night sky you have probably wondered what lies on the surface of distant planets; however, have you questioned what consists of the immediate, and seemingly empty, space between us and those planets? Dr. P.T. Jayachandran is doing just this. He has transformed his curiosity of space into a personal quest to improve human understanding of the fundamental properties that drive the behaviour of the region between earth and space, better known as the upper atmosphere. Dr. Jayachandran has spearheaded the development of a space research organization, The Canadian High Artic Ionospheric Network (C.H.A.I.N.), that provides open-source atmospheric data, increases navigation signal accuracy, and contributes to major breakthroughs in space physics. Ultimately this organization impacts everyday communication, transportation, and mapping systems.
Dr. P.T. Jayachandran - approved by Dr. Jayachandran
Dr. P.T. Jayachandran’s journey: from a curious space enthusiast to the founder of Atlantic Canada’s largest space research organization
Growing up in India in the late 60s and early 70s – a time noted by the establishment of the Indian Space Research Organization – propelled Dr. Jayachandran interest in space sciences. Dr. Jayachandran says that near his home the government launched rockets that “had instruments to probe the [atmospheric] medium up to 250 kilometers.” Witnessing the rocket launchings fostered a curiosity in Dr. Jayachandran to learn how the atmospheric data was used and if it had an impact on the public. He carried these questions with him throughout his life; thus, as he pursued post secondary, he let his interest in space govern his education choices. Dr. Jayachandran decided to follow a career in space research by studying Physics as an undergraduate student at the University of Calicut and then acquiring his Masters and PhD student in Space Sciences from the University of Andhra. In graduate school he was tasked with his first project as a space scientist, where he developed a high frequency (HF) doppler radar to study the atmosphere - a radar that was then used by the Indian Space Research Organization. Upon finishing his PhD, Jay set his sights on working at Western University in Canada. The change in location came with a change in the atmospheric medium for which he studied.
“When I was doing my PhD I did everything on the equatorial region, where the magnetic field lines are parallel to the earth, but in Canada the research is on the polar region, where the magnetic field lines are perpendicular.”
In 2005, following his years at Western, he came to the University of New Brunswick (UNB) where he established a space research organization to study the upper atmosphere. The organization, C.H.A.I.N., is currently a global leader in data acquisition and research regarding the atmosphere.
Earth’s Electromagnetic Field Lines. Note the parallel lines at the equator and perpendicular at the poles.
Scientists at C.H.A.I.N. focus on studying a region of the upper atmosphere, named the ionosphere, which ranges in altitude from 70 kilometres to the boundary of space. The ionosphere consists of ionized gas caused by the interaction of electromagnetic waves, emitted by the sun, with the neutral gases of the atmosphere, such as Oxygen, Nitrogen, and Hydrogen. “For example, oxygen has a certain binding threshold and if it receives energy above this threshold then electrons are knocked off, creating ionized gas.” This medium, or plasma, has intriguing effects on radio signals (and other electromagnetic waves) that are passed through the atmosphere. A transmitted signal will reflect off the ionosphere if it has a low frequency; however, if the wave exceeds the critical frequency then it will pass through. This phenomenon causes changes, or perturbations, in the radio signals emitted through the atmosphere. “We can [use this effect] to reverse engineer the medium [(figure out the elements that make up the ionosphere)] by looking at the signals coming out” explains Dr. Jayachandran.
Fundamental measurements, using radio techniques, are conducted to create a real-time map of the ionosphere.
Two radio techniques are employed by C.H.A.I.N. to observe the ionosphere from both the bottom and top. First, ground-based radars, or ionosondes, can transmit signals to the ionosphere and observe the reflected content. Second, C.H.A.I.N. uses receivers to capture radio signals transmitted by satellites; thus, acquiring data about the top of the ionosphere. To summarize, “the fundamental quantity being measured, [by these devices], is the density of charged particles in the atmosphere,” says Dr. Jayachandran.
Dr. Jayachandran at one of C.H.A.I.N. 's radio stations in Nunavut.
C.H.A.I.N. obtains real-time data through a network of radar and GPS receivers located in the Canadian Artic. The first stations were installed by the founders of C.H.A.I.N., including Todd Kelly and Dr. Jayachandran, and has grown into an elaborate expanse of devices. “We started with 3 and now we have 28 stations in the artic” says Dr. Jayachandran, “with the northernmost station being in Alert, Nunavut”. Not only has the instrument infrastructure grown, but C.H.A.I.N. has also attracted scientists from around the world and employs 26 individuals. Currently, the talented team at C.H.A.I.N., including engineers, graduate students, scientists and undergraduates, are working on many projects related to the upper atmosphere. One of these projects includes developing a real-time 3D model of the ionosphere. Another, led by a graduate student at C.H.A.I.N., observes and proposes explanations for signal fluctuations. The major project for the organization, however, is producing a new iteration of radar used to measure the ionosphere; thus, increasing the efficiency, accuracy and dependability of the data.
“What they have acquired from research so far has caused a feedback effect where they can improve their technology to then improve their data.”
A group of engineers and undergraduate students have designed the new instrument to have improved features such as faster analog to digital conversion, better interference handling, and an increased sampling rate. A site at the military base in Gagetown has also been established to test the functionality and viability of the new devices. With the first prototype almost complete, C.H.A.I.N. is aiming to have the new ionosondes installed within the next two years.
The research performed by Dr. Jayachandran and other scientists at C.H.A.I.N. has a widespread impact on human communication and transportation. The signals used by devices, including cell phones, GPS, and televisions, pass through the upper atmosphere; therefore, to provide safe and dependable navigation, it is essential to account for the signal error and fluctuations caused by the ionosphere. Organizations such as the Department of National Defense, Trimble Navigation, NAV Canada, and the Canadian Space Agency have partnered with C.H.A.I.N. to use their data for real-time correction of navigation signals. Furthermore, C.H.A.I.N. data is Open Source and is used by over 500 institutions across the world. “We also have about 20 to 25 direct collaborators” says Jay, which includes individuals from Norway, the U.S., China, and France. Facilitating global collaboration has accelerated C.H.A.I.N.’s goal to address fundamental questions of solar-terrestrial interactions.
Dr. P.T. Jayachandran and his team at C.H.A.I.N. have a meaningful impact on human communication and transportation
For interested undergraduates there are many opportunities to join Dr. Jayachandran and perform research in the fast-paced environment at C.H.A.I.N. Annually, the organization hires 5-6 students who spearhead hands-on projects in areas including hardware design, data analysis, software development and fundamental research. Dr. Jayachandran recommends that students who are interested in research should “go for it and ask themselves what truly interests and motivates them.” He also suggests that a scientist must be prepared to face adversity and “that in research failure is a success, because we tried something and now we understand that it is not going to work, so we won’t try it again.” A highlight of Dr. Jayachandran’s scientific career has been sharing ideas with undergraduate students and collaborating with them on research projects.
Research opportunities for undergraduates at C.H.A.I.N.
Many aspects of the ionosphere, such as the cause of northern lights and 40% of radio signal fluctuations, remain without an explanation. Dr. Jayachandran and the other scientists at C.H.A.I.N. strive to leverage their data and collaborate with other institutions to provide viable answers to these unknowns. Ultimately, Dr. P.T. Jayachandran transformed his life-long curiosity into a reality; a reality where he initiated the implementation of a nation-wide radar system, collaborated with industry partners to develop more accurate navigation systems, and accelerated the human understanding of the atmosphere.