The Life Scientific: Washington Yotto Ochieng

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1:07Hello.

1:08Washington Yotto Ochieng:Let me take you back briefly to the 1970s and a clear night in western Kenya. A young boy lies on the ground watching a faint light move steadily across the sky. A plane on its way to London, his mother explains. And when he says he wishes he could travel on it, she tells him, you needn't just be on a plane, one day you could build them. That boy was Washington Yoto Ochieng, now Professor of Engineering at Imperial College London and President of the Royal Institute of Navigation. Over a career bridging industry and academia, Washington has helped shape the movement of urban transport, how GPS satellites guide us and locate us, and how governments manage the technologies underpinning so much of modern life.

1:50Washington Yotto Ochieng:He now plays a key role in encouraging the next generation of engineers across the UK and Africa and has been recognised with awards including his CBE and Kenya's prestigious Order of the Burning Spear. This journey from plane spotting on the shores of Lake Victoria to developing the invisible systems that keep our world moving just goes to show how small early sparks of curiosity can end up shaping big life achievements. Professor Washington Yotou Chiang, welcome to The Life Scientific. Thank you very much, Jim. I'm delighted to be here. It's a little early in the show to be making corrections, but I'm going to start with one anyway.

2:26Washington Yotto Ochieng:In the introduction, I referred to this technology as GPS, which of course stands for Global Positioning System, because among the general public, that's become a sort of shorthand for the field as a whole. But actually, GPS is just the American version of this technology, isn't it? Yes, that's true. GPS was there at the beginning. and what happened was that the rest of the world basically got on the bandwagon. And so Europe decided that it would have its own global system, the one we refer to as Galileo. The Russians before that even decided to have their own GLONAS, which stands for Global Naya Navigazione Sistema Sputnikar.

3:07And then the Chinese were not to be left behind and they have their own global system that is called PEDO. So we had to find an all-encompassing name for them. And this is where Global Navigation Satellite Systems, GNSS, came from. So GNSS is the more accurate term rather than GPS. So GPS is a GNSS. VADO is a GNSS and so on.

3:28Washington Yotto Ochieng:This is really all about something called PNT. That's Positioning, Navigation and Timing. Can you just briefly explain what that involves? Yeah, it's interesting because positioning, navigation and timing has been there since the beginning. It's not as if we are inventing PNT now. What's the beginning mean? So the beginning of life. Okay. We all navigate. We do it every day, actually. As you walk around, you navigate. You're always aware that you are positioning yourself, you're timing yourself, and you're navigating from A to B. What has actually happened is that the requirements have become more stringent.

4:05How accurate is my position? how accurate is my time. And this is where the challenge has been, if on top of that, you add security, resilience, and so on. So the performance that's needed has become even more stringent, meaning that we have now had to find new modern ways of doing it.

4:23Washington Yotto Ochieng:And of course, these modern ways involve these satellites that are in orbit around the Earth. Most people, I guess, are familiar with using Google Maps. And all of that uses this GNSS system, whichever country has set up its own system. Correct, Jim. So what happens is that we have to model the Earth into a mathematical surface, which effectively means that we can represent position using numbers. We call them coordinates. Then you create a frame, like an ellipsoidal surface, which means that now we can divide the globe into effectively a geometric matrix where you can actually have your latitude, longitude, and so on.

4:59So your position are just numbers. When you take the numbers, then you impose them on a map, then you get your location. So the location is the physical manifestation of the position. Right, right, right. And the reason I'm saying this is because you mentioned maps. If you're navigating in your car and you end up being in the wrong place, it is not necessarily the map. It could be that the position from GNSS is the problem. Or it could be that the position from GNSS is correct, but the map is the problem. So we need to be very clear about that.

5:31Washington Yotto Ochieng:Yeah. What I love about it as a physicist is how we get those coordinates, because you need to receive these radio signals from several satellites. Correct. But you need to know how far away they are. And you don't know how far away they are. You have to work it out. And distance is speed times time. You know the speed is the speed of light because that's a radio wave. And the bit that I love is the timing, because, of course, the satellites use the atomic clocks. And Einstein tells us time runs faster when gravity is weaker up in orbit. And so you've got to correct for Einstein's theory of relativity.

6:03Washington Yotto Ochieng:So all the technology I sort of have to wade through in order to say, and it's all thanks to Einstein. And you would be spot on. Of course, we mentioned people use apps like Google Maps. But you've spent your career working on systems that go way beyond that. How important is this technology? So I was part of a government expert panel that was looking at our dependency on GNSS, particularly from a critical national infrastructure perspective, including transportation, energy, communications, even defence. And so what has actually happened is that PNT systems like GPS and so on have now become critical to the actual day-to-day living.

6:44That's how important they are. So what would happen if a satellite that's integral to our GNSS systems went down? It would be catastrophic. So there was a study that was conducted a few years ago now by London Economics, which estimated£7 billion of loss for a five-day outage of GNSS for the UK. My specialist knowledge tells me that they grossly underestimate it. I think it's probably 10 times more than that. Wow.

7:16Washington Yotto Ochieng:In the introduction, Washington, I mentioned that lovely story about your mother encouraging you as a youngster. So let's hear a bit more about that childhood. You were born in 1964 in Kendu Bay, a town on the edge of Lake Victoria in Kenya. What was it like growing up there? It was fantastic. I mean, we were to some extent fishing people, but also pastoralists. So, you know, if we were not in school and not playing football, we were in the mountains with the sheep, goats and cattle. And, you know, looking back, it was a very, very enjoyable time. Tell me about your parents. So my parents are both late now, but my mom was a housewife.

7:57Dad was a medic, as well as an agricultural specialist. the joke was always and I think but I think it was true that that if we had any brains it came from mom what I found remarkable is that you were the 12th of 14 children yes what were you like then as a kid honestly a little bit cheeky I think because you know when you have eight kids around the table mom is trying to feed you you got to be quite clever in terms of getting enough because if you're not smart, then in a blink of an eye, it is gone, right?

8:33Washington Yotto Ochieng:And you started making an academic mark early on, particularly in maths, physics and chemistry. And you won a place to study engineering at the University of Nairobi. But first, you had to do a compulsory stint in Kenya's National Youth Service. What was that like? I look back at it now. And it's bizarre when I tell people, they don't believe me that I would it again. Because I think that's where I actually grew up. And that was quite grueling. I mean, we were being trained, just like you train soldiers, but without the gun. I remember we're using spades to represent the gun. But it was basically community work, but with a lot of physical training.

9:13I remember those days, we could climb hills, you know, without blinking. That's how fit we were. The downside to some people was that when we eventually got to university, we became fairly political. And so the politicians found us a little bit of a thorn in their flesh. Because you had the self-confidence to speak out. And physical fitness. It wasn't just speaking out. I mean, we had some runnings with the police from time to time.

9:38Washington Yotto Ochieng:Oh, goodness me. Well, that was when Daniel Arapmoy was president of Kenya. And although he held that role until 2002, I think he faced quite a bit of dissent during his time. This is absolutely true. And a significant component of that dissent was us as university students. And we were ready not just for justice, but we were also ready for change of governance. and so it was an unusual scene in Nairobi to have running battles with the dreaded general service unit police, GSU as we used to call it. And to me looking back that was also a wonderful part of what we were doing as young people who wanted the best for their country.

10:23Washington Yotto Ochieng:Well as you say you did eventually get to university. You graduated with first class honours and went on to become an assistant lecturer there. But you also wanted to continue with your studies. And I gather you made it your mission to win a place at a top international university. Tell me about that. Oh, that was interesting. I mean, I must have done 100 applications. Yeah. And this is no lie. It was the last one. You know, when I was just about to give up, that came back positive. That letter, I gather, changed your life. Yeah. So it was a simple letter from the University of Nottingham in the United Kingdom, from Professor Vidal Ashkenazi, which basically said, good news, I've managed to find you a full scholarship to come to the University of Nottingham for a master degree and enclosed, please find a return ticket.

11:16Wow. And that everything was arranged. I just had to get myself on the plane and study. That's remarkable. And this, I get a little bit emotional about it. I was going to ask you, I mean, can you remember how you felt at the time reading that letter? Well, I mean, you miss a beat, you know, and then you wonder why you. But I've done it at the university where I am, creating a few scholarships for overseas students because it's quite expensive. And I always think, you know, how it was. You experienced it personally. Yeah.

11:45Washington Yotto Ochieng:So you moved over to the UK. You settled in Nottingham. Let's get on to your work in PNT. Reminder for listeners, that's positioning, navigation and timing. Your master's degree was quickly followed by a PhD, which focused on GPS accuracy. At a time when that technology was being deliberately downgraded for civilian users, why was that? So GPS, when the Americans designed it, they originally intended for the service that's available to ordinary people to be a little bit low in terms of accuracy compared to what would be available to what they call authorized users. That includes the military. So they created two services.

12:30One is called the Standard Positioning Service, and the other was the Precise Positioning Service. So the PPS is the one that was encrypted. And for the rest of us, was the Standard Positioning Service, which was delivering an accuracy of about 100 meters. So for those particular applications that requires accuracy better than that, it was obviously a problem. So we set about looking at the way it was implemented and its effects. And we found out clearly that there was a way of circumventing that. Aha. So what was that? So it's something called differential GPS. What that actually means is that you establish a reference station where you put a receiver and you know the position, what I was calling the coordinates.

13:13And based on that, we can compute the effects that the Americans had put on the satellite orbits. So in implementing this selective availability, they interfered with the accuracy of where the satellite is. And they also interfered with the timing. So the two things that you need to give you that high accuracy, they had basically injected deliberate errors on them. What we discovered was that those errors correlate over distance. So if we can calculate them in one location, we can transmit those corrections to users nearby and got rid of it.

13:47Washington Yotto Ochieng:Ah, okay. So when the US lifted this restriction on selective availability, that didn't happen until, I think, the year 2000. Yeah, with Bill Clinton, yes. Yeah, right. I'm sure there were a lot of factors influencing their decision, but did it feel like a bit of a win for you? It did. And the opening up of GPS full accuracy to the entire world, goes with my societal instincts in terms of you know making a positive impact. Well certainly if these days Google Maps or your sat nav in your car didn't work to within accuracy of any less than 100 meters you'd be stuck wouldn't you? It's true and in fact you know we are trying to navigate aircraft gate to gate using space-based techniques and as you know as the aircraft approaches the runway the vertical accuracy particularly has got to be really good.

14:40You're talking about centimeters in terms of accuracy forget about 100 meters yeah now GNSS can give you millimeters a lot of people don't know and alongside the millimeter in position you can actually get five nanoseconds in terms of time from something that is 23 ,000 kilometers away from here yeah it's incredible almost like magic isn't it well after a couple of years as a senior

15:05Washington Yotto Ochieng:researcher at Nottingham, you joined a big British electronics firm, Raycal, and started working on a pan-European project to improve regional PNT technology. This paved the way for the Galileo project, which we mentioned earlier, which is the EU-owned equivalent of GPS. That's correct. Of course, we, the UK, were part of the European Union when Galileo was developed, so we were big investors and a part owner. But that changed after Brexit, didn't it? Yes, probably one of the lowest moments of my career, having been in there in the middle of it, working with our European partners. So thanks to Brexit, we got out of those PNT programs, to the extent that we then now have to figure out what happens to the UK.

15:52But yeah, it was a low point. So realistically, how long will it be before the UK has its own PNT system? because we don't have our own GNSS and we're depending very much on other people's GNSS. There has to be something else in there. So what we're talking about is a resilient system of systems PNT, an architecture that gives us what we might call sovereign PNT capability. That's what we're working on now. So it's a mixture of things. It's a combination of things. And how far off is it? A fair distance, but there are very, very tangible steps that are being taken.

16:31Washington Yotto Ochieng:In 1997, Washington, you went back to academia as a lecturer at Imperial College London. Once you got back to research, you kicked off what would become one of your most influential strands of work, studying how GNSS performs in urban environments, where, of course, things like tall buildings, tunnels and sort of interference can cause all sorts of issues. Yeah, so it's very interesting. When you think about GNSS, those satellites are in what we call medium Earth orbit, so around 20 ,000 to 23 ,000 kilometres from here. So basically, when the signal gets here, it's pretty weak. They're part of a light bulb.

17:10So, you know, signal degradation, reflection, what we call multipath and so on, they're very, very common in built environments. And then you have the problem of signal blockage, which means that the availability of the signal is also down. And we want to make sure that we guarantee the solution. We call that integrity. So we wanted to characterize the GNSS signals in these environments so that we can design a system that works. And also to include other things that we might combine with GNSS to provide this accuracy, integrity, continuity, and availability of positioning. as needed for things like locating buses.

17:49Washington Yotto Ochieng:Well, that work certainly had a big impact, not only feeding into other research, but also real-world applications like London's bus tracking system. How did that work? Obviously, when you travel in London and you look at the bus stops and so on, you see this screen that gives you a display of how long for the next bus to come. I mean, that has a back-engine computer, right, that actually knows where the buses are at any given time, can predict everything and so on. Now, that also means, therefore, that the buses have to have a positioning and timing capability that then feeds into the calculator, if you like, the computer.

18:26And that needs to have a level of guarantee, as we've talked about. What we found when we started working with the buses was that the integrity measure wasn't really handled that well, particularly in a system that uses more than GNSS. So we went about developing what I refer was the integrity layer. Call it the security guarantor layer of the system. That's what is actually being used today in iBus. So it's intelligent bus location system in London. So it's not just using GNSS. It's not just locating the buses using satellite signals. Yeah. So it uses satellites and it uses something called dead reckoning or deduced reckoning sensors, which effectively is sensors that give you direction and displacement.

19:07So using very simple maths, you can determine the change in your position in terms of coordinates. And those are not jammable, like GNSS is jammable. So when you combine in a clever way synergistic systems and sensors, you end up with a performance level that you need.

19:27Washington Yotto Ochieng:Well, let's stick for a moment with London traffic, because your work also helped inform plans for the congestion charge, which came in in 2003 and was hugely controversial in certain quarters. I gather you agreed with the principle but had a different view on how it should be handled. Yes, my argument was always that you could charge for using the road space, just like you charge for using energy and so on, because it is a utility. And it means that there has to be a link between the charge you pay and how much of that utility you use. So that was my basic premise. And so the technology that you'd implement for doing that should be able to affect what I refer to as variable charge, depending on how much of it you use.

20:11So what you don't want is basically to say you're going to pay£10, whether you spend five minutes in the zone or whether you spend a whole day. I thought there's a level of unfairness there. But the technology that was adopted, which is basically based on fixed cameras, could not really distinguish the usage part. my suggestion was that you could employ GNSS together with our dead recording sensors if you wanted to be able to effect this variable charge. I don't think TfL said no. I think their argument was that there was a problem with the technical maturity at the time. But till today we are still on the fixed charge.

20:49So from your perspective do you think the scheme as it stands has worked? At the beginning the data showed that speeds were a little higher and so on. But then there's this thing called induced demand, where people who are not actually driving, when they see that there is space now, they start driving. And so what you'd have seen over the years is that there has been a reduction in that kind of speed advantage from the charge.

21:11Washington Yotto Ochieng:Well, Washington, back at Imperial, you went on to become head of the Department of Civil and Environmental Engineering, and a scientific advisor to the UK Department for Transport. And your recent work has focused heavily on resilience, protecting PNT systems from failure or attack. Now, we spoke earlier about how crucial satellite navigation systems are to keep our world working. So what's the solution? How can we safeguard ourselves in case something goes wrong? So I refer to this as a pentagon. I call those sides of the pentagon threat vectors. One is cyber, things like jamming and spoofing of GNSS is a cyber problem.

21:54We have environmental pollution and so on. You have biological problems like the pandemics. And then you've got physical problems. And then there's the most important threat vector of all the five, people, us. So those five are of concern to me. The other thing that's of concern is the fact that they're increasingly occurring simultaneously. So you're flooding while your health system is also being hacked, for example. And being able to understand the impact of all of those five vectors individually, but also in combinations on, for example, critical infrastructure is quite important. And so we are approaching it from that dimension of multi-hazard modeling and analysis and ensuring that things that are critical to the underpinning of society, ideally are robust, which means that they operate in the presence of disruptions.

22:49Or if there's a disruption, then we recover pretty quickly. So this is the whole concept of resilience that we're working to. Is a solution to build more satellites, having them in lower Earth orbits? Yeah, so there is this proliferation of satellites in LEO or low Earth orbits. We talked about GNSS. They are in medium Earth orbits. The LEO constellation has traditionally been for remote sensing, so basically imaging the Earth. but of recent times PNT is moved in there through for example Iridium and Starlink everybody's trying to put navigation payloads in Leo orbits which start from about 160 kilometers to 2 ,000 something like that so it's pretty close to us the advantage is that the distance traveled by the signal is not as long as the 23 ,000 kilometers so the signal is a lot stronger which means that it's much more difficult to jam.

23:46So people who are advocates of LEO P &T will tell you that's a big advantage. The other thing they'll be telling you is that it's much more amenable to small satellites as opposed to the bigger payloads that we put up in MEO and GEO Orbit. So there are advantages people will tell you. I don't know whether they'll be shouting about this but you need thousands of those satellites to cover the globe to provide you with the coverage you need to give you the 3D position and time. And so there is that question also of how many satellites, and given the players who want to build their own systems, they're actually cooperating.