The Professor who doesn't let you get lost.
By
Khuswant Singh
Dr. Mohinder Grewal
Dr. Mohinder Grewal
The MX (for “missile experimental”) was the most-sophisticated ICBM fielded by the United States during the Cold War against the Soviet Union. Under development from 1971, it evolved into a 22-meter (71-foot) missile with a “bus,” or fourth stage, located in its front end that carried 10 or 12 independently targeted warheads (or MIRVs). This endowed each missile with several times the firepower of the two- or three-warhead Minuteman III, which it was designed to replace. In addition, the missile’s extreme accuracy—made possible by an inertial guidance system updated in flight by signals from navigation satellites—gave its 300-kiloton thermonuclear warheads greater potential to destroy reinforced missile silos and command bunkers in the Soviet Union. The MX had a range of approximately 11,000 km (7,000 miles).Northrop had a contract to develop the ‘floating ball navigation system’ of the missile to navigate.
Chairman-Department of Electrical Engineering
In 1980, Mohinder Grewal was elevated to the coveted post of Chairman of the Department of Electrical Engineering, a rare honor for a person of Indian origin. Not only was Prof. Grewal involved in building navigation systems for the aerospace Industry, but he was also at the helm of building a full generation of future engineers who would take this technology to levels seen in the twenty-first century. A rare feat indeed! “I built the Electrical Engineering department with a lot of passion, and it had great faculty,” he says with such a delightful smile on his face that as an interviewer, your chest swells in pride to be talking to an academic of such honors. “It grew from five faculty to twenty-eight in my seven years of chairmanship from 1980-1987.” The nameplate outside his office room read Chairman, Prof. MS Grewal, Ph.D., PE. PE meant a Professional Engineer license that allowed an engineer to offer his/her services directly to the public. Having a PE license meant that the said engineer had met certain educational and experience requirements, signifying his/her ability to design, supervise, and approve engineering projects as per the law.
Soon, the new responsibility threw new challenges, as it became difficult for him to do an almost 100-mile triangle every day, which included heading to the university, then the Northrop Office, and back home. The situation was salvaged by one of his students, who, while doing his Masters in Control Systems, was working with Rockwell International, a major American manufacturing conglomerate involved in aircraft, the space industry, defense, and commercial electronics components. According to Mr. Ken Green, his student, the Chief Engineer of one of the departments was looking for a Ph.D. in Control Systems and Prof. Grewal was perfectly qualified for that post. “Rockwell International had the same contract that Northrop had of building the floating ball navigation system. In fact, Rockwell had overall responsibility for building it, while Northrop only had a subset of it, so it made more sense for me to shift to Rockwell. Rockwell International employed me as a consultant, and at the same time, they were also developing the Global Positioning System (GPS), and I started working on both the projects. According to Prof. Grewal, “the main part of the GPS is the Kalman Filtering system, which is my specialization. It is basically a mathematical algorithm used to estimate the state of a dynamic system for a series of noisy measurements from GPS. It is the glue that keeps the system together. My role was to apply Kalman Filtering effectively, by filtering out the noise and inaccuracies from GPS measurements.”
In 1997, Dr. Grewal ceased consulting for Rockwell International, which had now become Boeing. “At that time, not much was happening, but around the time I stepped down, a new development took place.” The FAA aimed to enhance the accuracy and integrity of GPS, awarding Hughes Aircraft Company a contract. They sought to integrate GPS into commercial flights, a critical need despite its development by the US Defense. One of Dr. Grewal’s students from 1977, employed with Hughes, knew exactly whom to contact to fulfill the terms of the contract. “I remember him calling me and requesting me to join the coming Monday itself, which I did. My job was to improve the integrity and accuracy of GPS with WAAS. The objective of my consultancy was to develop the Wide Area Augmentation System (WAAS).” As the calendar moved to the twenty-first century, Dr. Grewal authored the first edition of his book on the Global Satellite Navigation system. He concluded his consulting in 2005 after the FAA had approved the WAAS for navigation. This was also a time when Dr. Grewal had dedicated almost 30 years of his life to academics and consultancy. We reached a moment in our interview where Dr. Grewal got emotional about his journey and started narrating it in a very nostalgic manner. I knew I should not interrupt his flow, for within it lay a lifetime of academic and professional achievement rarely found on regular resumes. ‘I still remember the day my father and his brother-in-law dropped me at the airport along with the driver. I was so scared when I got onto the airplane.’ Ironically, little did he know that a couple of decades later, the same airplanes would be using a navigation system on which he had worked tirelessly? “Life has been very busy in the sixty-two years that I have been here,” he says. “I still have a vivid memory of the day when America experienced the assassination of President JFK Kennedy and when Martin Luther King delivered his iconic speech, ‘I have a dream.’ I also came with a dream, and perhaps I have lived that dream.”
“I’ve worked with Hughes Aircraft Company, Raytheon, Northrop, Boeing, Rockwell, and Lockheed Martin as a consultant. In my career, I have written two books, each with four editions, both translated into Chinese, published papers, and presented at many forums. Primarily, they cover Kalman filtering theory, GPS, and INS, which is an inertial navigation system, taking over if the GPS gets blocked. In the era when there was no GPS, all airplanes were flown using multiple INS, meaning if one failed, the other took over. In a nutshell, my career spans as a consultant, academic, expert witness, author of books, and contributor to papers on the cutting edge of technology.
Expert Witness
The term ‘expert witness’ intrigues me, and I prod him to share something, which he does when Apple Inc. hired him in January 2016 after someone sued Apple, alleging it used its algorithms of Kalman Filtering in its GPS application in the phone with minor alterations. The company soon decided to withdraw the case for various reasons. But the story doesn’t end here. Since, as per guidelines, Dr. Grewal was only interacting with the big-shot attorneys and not allowed to meet any of the employees, he, during the course of meetings with them, asked them to find out from where Apple got these algorithms. To his pleasant surprise, he was informed at the next meeting that Apple had sourced it from page no 357 of his book on Kalman Filtering. Dr. Grewal then requested a copy of it, which he was provided with a stamp for his eyes only. He shared many other incidents with him clinching cases wherever he appeared as an expert witness.
Publications, Awards & Guru Nanak Dev Engineering College
Currently, I’m presenting my one-week short course to the industry on the application of Kalman filtering, GPS, and INS. Back in 1979 when I started, it was a longer course, but has altered it as per audience demand and technology. Its audience includes people from all over the world, including the Middle-East, Europe, Asia, etc. Originally, a course taught in classrooms, post-COVID it’s on Zoom. The books are co-authored and have been through many editions as they need continuous updates. They are also available in the Chinese language.
