Speaker 1: Get in touch with technology with tech Stuff from how
Speaker 1: stuff Works dot com. Hey there, and welcome to tech Stuff.
Speaker 1: I'm your host, Jonathan Strickland. I'm an executive producer at
Speaker 1: How Stuff Works and All Love All Things Tech. And
Speaker 1: in my recent episode profile of alfred Ley Loomis, if
Speaker 1: you haven't listened to that one it published last weeks ago,
Speaker 1: check that out. I mentioned that Loomis was instrumental in
Speaker 1: developing a technology called Lauren l O R A N.
Speaker 1: And today I'm going to talk about that technology in
Speaker 1: deeper detail and how it uses mathematics and radio signals
Speaker 1: to help ships navigate far off the coast, or rather
Speaker 1: how it used to do that, as the system has
Speaker 1: since been phased out, but more on that later. I
Speaker 1: do think that Lauren is pretty cool, and it does
Speaker 1: give me a chance to talk about mathematics a little
Speaker 1: bit now, as we'll discuss in this episode. I won't
Speaker 1: go into incredible detail mathematically speaking, because it involves things
Speaker 1: like hyperbolas, which are way easier to talk about with
Speaker 1: the use of visual aids. However, first I should give
Speaker 1: some background on laur Anne. In the nineteen forties, there
Speaker 1: was no such thing as the Global Positioning System or GPS.
Speaker 1: You could not turn on a computing device and activate
Speaker 1: a helpful little app to see where you were on
Speaker 1: the globe. No one had invented a rocket capable of
Speaker 1: reaching orbit, let alone put a satellite out in space
Speaker 1: at that point. Yet there was a need for reliable
Speaker 1: navigation systems for ships and later on for aircraft. This
Speaker 1: need was made more urgent when the Second World War began.
Speaker 1: So you had different systems that were already in place,
Speaker 1: but many of them relied upon the elements things like
Speaker 1: seeing where the sun was and making measurements using something
Speaker 1: like a sextant. You had ships even leading up into
Speaker 1: World War Two that we're dependent upon these kind of systems,
Speaker 1: and for commercial ships that didn't have the benefit of
Speaker 1: military technology, this lasted even longer, and that was not
Speaker 1: ideal by n It seemed the question wasn't if the
Speaker 1: United States was going to be pulled into the Second
Speaker 1: World War, but rather when. Because of this impending threat,
Speaker 1: several important people urged President Franklin Roosevelt to form a
Speaker 1: Special Scientific Council to head research and development projects in
Speaker 1: science and technology that could be useful during wartime. Among
Speaker 1: these people were Vanavar Bush, who served as scientific advisor
Speaker 1: to the President. James Knant, who was president of Harvard
Speaker 1: at the time, and Carl Compton, who was president of
Speaker 1: m I. T. Roosevelt approved the plan, and the National
Speaker 1: Defense Research Council, or in d r C was born.
Speaker 1: The council looked at different technologies for detecting aircraft, often ships,
Speaker 1: and decided that microwaves were the most promising. Lead Carl
Speaker 1: Compton reached out to Alfred Lee Loomis to head up
Speaker 1: a special committee called the Microwave Committee to look into
Speaker 1: the matter. Loomis and his team determined that microwaves could
Speaker 1: be ideal for a detecting aircraft, but that the US
Speaker 1: had no technology capable of emitting microwaves in the frequency
Speaker 1: range they desired and enough power to work properly. Meanwhile,
Speaker 1: in Great Britain, scientists had developed a magnetron capable of
Speaker 1: creating powerful microwaves in those frequencies. Great Britain sent a
Speaker 1: group of scientists to the United States to try and
Speaker 1: develop a radar system that could take advantage of this technology.
Speaker 1: Sir Henry Tizard and his team brought over a cavity
Speaker 1: magnetron and Loomis invited the UK scientists to meet with
Speaker 1: the Microwave Committee. The committee convinced Compton to set aside
Speaker 1: a space at m I T for research and development
Speaker 1: with microwaves, and the m I T Radiation Laboratory or
Speaker 1: rad Lab was born. Now, the reason they chose the
Speaker 1: name Radiation Laboratory was pretty interesting. It was all a
Speaker 1: matter of deception of misdirection. The lab did not want
Speaker 1: anyone associated with the Access powers to find out what
Speaker 1: they were working on, so the Allies could maintain an
Speaker 1: advantage during the war, especially when it came to navigation
Speaker 1: and detection of aircraft and other vessels. So to that
Speaker 1: end they chose the name Radiation Laboratory for a siwhat
Speaker 1: paradoxical reason, or at least in retrospect, it seems paradoxical.
Speaker 1: It made it sound as though the lab was investigating
Speaker 1: nuclear science, as in things like nuclear power and potentially
Speaker 1: a nuclear bomb. Not At the time, the prevailing feeling
Speaker 1: was that nuclear science was such a young discipline that
Speaker 1: would take too long to make any advances in the
Speaker 1: field that could possibly have an effect during the war,
Speaker 1: and and so they chose to disguise their efforts to
Speaker 1: advance radar technology by claiming to be a nuclear science lab,
Speaker 1: which I think is pretty wild, especially when you consider
Speaker 1: that the actual end of World War Two would be
Speaker 1: in large part due to the development of nuclear weapons.
Speaker 1: The lab made significant contributions to science and technology, with
Speaker 1: numerous practical applications. Among them was the Long Range Navigation
Speaker 1: System or LAUREN. Now, the story of LAUREN really gets
Speaker 1: going on October first, nineteen forty, when the Army Signal
Speaker 1: Technical Committee met to create requirements for what it called
Speaker 1: a precision navigational equipment for guiding airplanes. The committee was
Speaker 1: asking for a means to provide navigational assistance from a
Speaker 1: distance of five hundred miles, a flight ceiling of thirty
Speaker 1: five thousand feet, and inaccuracy of within one thousand feet
Speaker 1: at two hundred miles out. In other words, a planes
Speaker 1: navigator should be able to determine the planes position within
Speaker 1: one thousand feet of its act tool position while still
Speaker 1: two hundred miles out from the radio transmitters that are
Speaker 1: beaming signals to the plane. Alfred Lee Loomis had a
Speaker 1: proposal to meet these requirements. He thought that this would
Speaker 1: originally be used for ships, not for aircraft because it
Speaker 1: would require building special receivers, and at the time, there
Speaker 1: wasn't really a practical way of building a receiver small
Speaker 1: enough to fit on an aircraft, which already had a
Speaker 1: pretty strict limit on how much weight and how much
Speaker 1: space was available in them. Loomis had a clever idea
Speaker 1: that involved pairs of radio transmitting stations sending out synchronized signals.
Speaker 1: A receiver aboard a ship would pick up these signals,
Speaker 1: and by measuring the delay between the two signals, you
Speaker 1: could figure out your basic distance from the two transmitters.
Speaker 1: With a second pair of transmitters or a third transmitting tower,
Speaker 1: you could figure out your actual position. And it all
Speaker 1: had to do with the formulas for hyperbolas, which is
Speaker 1: why laura and is also known as a hyperbolic navigation system. Now,
Speaker 1: I know all the mathematicians out there already have a
Speaker 1: firm grasp of what a hyperbola is, but for some
Speaker 1: of us we might need some instruction or refresher It's
Speaker 1: been more than twenty years since I took a mathematics course,
Speaker 1: and I needed a little reminder for myself. So here
Speaker 1: we go. Hyperbola is a symmetrical open curve that represents
Speaker 1: this set of points in a plane whose distances to
Speaker 1: two fixed points called folk i in that same plane
Speaker 1: have a constant difference. So by a symmetrical open curve
Speaker 1: we mean you have two curved lines called branches or
Speaker 1: connected components. They are symmetrical, so they are mirror images
Speaker 1: of each other, with the open side of the curves
Speaker 1: facing outward from each other. They look kind of like
Speaker 1: infinite bows. As the arms extend out from the center
Speaker 1: of the hyperbola, which is called the vert vertex the
Speaker 1: verticey ease of the hyperbola, they become less curved. So
Speaker 1: the further out the lines go, the more straight they appear.
Speaker 1: The two fixed points or foci, are each on the
Speaker 1: inside of one of those curves or branches. Now remember
Speaker 1: the branches represent a set of points. If you were
Speaker 1: to select any of those points along one of the curves,
Speaker 1: you can measure the distance between that point and the
Speaker 1: two foci. The point will be closer to its own
Speaker 1: focus than the focus of the other curve, and you
Speaker 1: subtract one distance from the other and you take the
Speaker 1: absolute value, meaning you make it a positive value. So
Speaker 1: if it would have been negative, you change it to
Speaker 1: a positive You will then find the constant for that hyperbola.
Speaker 1: If you were to pick any other point on that
Speaker 1: same curve and repeat this process where you measure the
Speaker 1: distance between that point and the FOLCA and it's foci
Speaker 1: and that point and the folk I of the other curve,
Speaker 1: and then subtract the two, you would still arrive at
Speaker 1: that same value. That woman, you take the absolute value.
Speaker 1: The folk I are in a position relative to the curves,
Speaker 1: so that the difference between the distance of any point
Speaker 1: on the curves and the folk I will always be
Speaker 1: the same. The curves thus represent a selection of possible
Speaker 1: locations from the perspective of the folk I. Now that's
Speaker 1: the secret behind Lauren. But how well I'll tell you.
Speaker 1: But first let's take a quick break to thank our sponsor. Okay,
Speaker 1: So imagine you've got a coastline, and along this coastline
Speaker 1: you have transmitting towers that are paired together so that
Speaker 1: they send out a pulse of signals in perfect synchronization.
Speaker 1: If you were on a boat out at sea equa
Speaker 1: distant from the two towers, you would receive both sets
Speaker 1: of signals at exactly the same time. But let's say
Speaker 1: you're a little closer to Tower A than you are
Speaker 1: from Tower B. What happens then, Well, Tower A and
Speaker 1: Tower B send out their signals at exactly the same time.
Speaker 1: It is synchronized, so you would receive Tower a's signals
Speaker 1: a little bit earlier than you would receive Tower b's signals.
Speaker 1: That's because the signals from Tower B have to travel
Speaker 1: further than the signals from Tower A, and the signals
Speaker 1: are traveling at a constant rate of speed. So what
Speaker 1: speed is that, Well, it's the speed of light, because
Speaker 1: radio waves are electromagnetic radiation, as is light now in
Speaker 1: our atmosphere, because light does travel at different speeds through
Speaker 1: different media. In the vacuum of space, it's one speed.
Speaker 1: But in our atmosphere light travels at two thousand seven
Speaker 1: kilometers per second. I'm really going to focus on kilometers
Speaker 1: for this. It makes it easier in the long run.
Speaker 1: So it's not like there would be a long delay
Speaker 1: between the two incoming signals. I mean that that speed.
Speaker 1: Unless you are really far away, you wouldn't be able
Speaker 1: to have a massive delay between the two. And if
Speaker 1: you were really far away, you wouldn't be able to
Speaker 1: pick up the signals in the first place. So, uh,
Speaker 1: we're talking about a delay that's measurable in micro seconds,
Speaker 1: but with a Loran receiver that's long enough to do
Speaker 1: some serious calculations. Now, the two towers that are transmitting
Speaker 1: represent the foci of a hyperbola. So you're on this
Speaker 1: boat and your receiver picks up that you're getting the
Speaker 1: signals from Tower A let's say about two hundred micro
Speaker 1: seconds before you get the signals from tower B, so
Speaker 1: you are closer to Tower A by a factor of
Speaker 1: two hundred micro seconds. You also happen to know how
Speaker 1: far apart Tower A and Tower B R because that's
Speaker 1: part of the whole system. You have to know the
Speaker 1: location of the transmitting towers and their distance relative to
Speaker 1: each other. Otherwise you don't have enough information to make
Speaker 1: any important determinations, and that information is freely available to
Speaker 1: anyone who's part of the Louran system. So you know
Speaker 1: the physical distance that separates these two folk i from
Speaker 1: each other along the coast. Using those pieces of information,
Speaker 1: you can actually plot the hyperbola curves. So let's say
Speaker 1: the two towers are four kilometers apart. The speed of
Speaker 1: the radio waves is point to nine nine seven nine
Speaker 1: two kilometers per micro second, and the difference between the
Speaker 1: two sets of pulses was two hundred microseconds. We can
Speaker 1: calculate the constant of this hyperbola by using the equation
Speaker 1: distance equals rate times time. The rate is the rate
Speaker 1: of the radio waves that's point to nine nine seven
Speaker 1: nine two kilometers per microsecond, and the amount of time
Speaker 1: that passes is two dred microseconds. That gives us fifty
Speaker 1: nine point nine five eight four kilometers. So let's just
Speaker 1: round it up. We're gonna call it sixty kilometers. That's
Speaker 1: your constant. Any point along the hyperbola will have a
Speaker 1: difference in distances from the two folk i of about
Speaker 1: sixty kilometers. Now, that still doesn't tell you where you
Speaker 1: are in relation to anything else. It just tells you
Speaker 1: the relationship between the difference in distances between the two transmitters. However,
Speaker 1: knowing the constant gives you enough information to suss out
Speaker 1: the rest of the equation for the hyperbola. The equation
Speaker 1: for an east west hyperbola. So if you were to
Speaker 1: plot this on the old X Y axis, you know,
Speaker 1: a good old grid, then this would be the ones
Speaker 1: that would face left and right, a north south hyperbola
Speaker 1: would face up and down along the y axis as
Speaker 1: opposed to left and right along the X axis. So
Speaker 1: when you plot and east west hyperbola on an x
Speaker 1: y axis, the equation for a hyperbola is X squared
Speaker 1: divided by A squared minus Y squared divided by B
Speaker 1: squared equals one. That's your your hyperbola equation. Now, if
Speaker 1: this were an up down a north south hype perbola,
Speaker 1: you would actually have Y squared over A squared minus
Speaker 1: X squared over B squared equals one. Just a little
Speaker 1: bit of mathematics for you. The A, by the way,
Speaker 1: represents the vertices. The that would be the the center
Speaker 1: of the hyperbola. That that point where it has the
Speaker 1: curve where it curves around the very center of that
Speaker 1: is the the of Both of those curves are the vertices,
Speaker 1: and the B represents the covertices. Describing that as a
Speaker 1: little more tricky without visual aids. So just go with
Speaker 1: me on this if you want to really understand what
Speaker 1: this is. There's a video I highly recommend. I found
Speaker 1: it extremely useful. The video that you can find is
Speaker 1: on YouTube. I have no connection to the person who
Speaker 1: makes this video or the company that makes this video.
Speaker 1: I just found it very useful. The title of the
Speaker 1: video is applying hyperbola as navigation, and it's by think
Speaker 1: Well VIDs, and you can see this applied specifically for
Speaker 1: the purposes of navigation. That even use an example very
Speaker 1: similar to what I'm talking about, although he uses miles
Speaker 1: rather than kilometers. Uh. If you check that out, you'll
Speaker 1: be able to see this in action, and it'll be
Speaker 1: much easier for you to visualize since I'm working just
Speaker 1: from an audio format here. The point being that once
Speaker 1: you figure out the equation for the hyperbola, you can
Speaker 1: plot out all those points on a map that have
Speaker 1: this this constant this constant difference of of distances between
Speaker 1: the two folki. So you get that curved line that
Speaker 1: represents all of those physical points on the map. We
Speaker 1: call this the Loran line of position. By itself, that
Speaker 1: information isn't that useful because you don't know exactly where
Speaker 1: along that line your position is. You just know that
Speaker 1: it has to be one of those points. Based on
Speaker 1: the math, you could be anywhere along that curve. Well,
Speaker 1: if you're on a boat, you would presumably be anywhere
Speaker 1: out over the ocean, because if the curve extends out
Speaker 1: over the land, you probably aren't there if you're in
Speaker 1: a boat. If you are there, then you don't really
Speaker 1: need to worry about your position so much, because chances
Speaker 1: are it's not really changing. Boats don't move well on land.
Speaker 1: What you need now is either a third tower that's
Speaker 1: pulsing the same synchronized signal, or, as the original design
Speaker 1: of Laurent intended, a second pair of transmitting towers. So
Speaker 1: with a third tower, let's remember our first two towers
Speaker 1: were Towers A and B. Uh this would be Tower C.
Speaker 1: You would run the same calculations with regard to the
Speaker 1: ship and Tower A. That will produce a second hyperbola,
Speaker 1: one in which the curve of that second hyperbola will
Speaker 1: intersect with the curve from the first hyperbola. If you
Speaker 1: were using a second pair of towers, we'll call these
Speaker 1: towers D and E, you would repeat the process you
Speaker 1: did for Towers A and B, measuring the difference in
Speaker 1: time it takes towers Tower D signal to get to
Speaker 1: you compared to Tower E signal. That would let you
Speaker 1: plot out a second hyper bluff, and you would still
Speaker 1: see a second set of points representing your possible location.
Speaker 1: More importantly, they would intersect with your first set of points,
Speaker 1: and it's at that intersection where the two lines cross
Speaker 1: that your location would have to be. That's the only
Speaker 1: place your ship could be, because the mathematics would tell
Speaker 1: you that you have to exist along both of these
Speaker 1: curved lines simultaneously, and they only intersect at one point.
Speaker 1: That point is your location. So by using a Loran
Speaker 1: receiver and taking in transmissions from different towers and applying
Speaker 1: a little math, you can figure out exactly where you
Speaker 1: are out in the ocean, even if land isn't in
Speaker 1: sight and the sky is overcast. By sending out these
Speaker 1: pulses with identify irs, you'll know where you are in
Speaker 1: relation to where you're headed and can make course corrections
Speaker 1: and take the measures to pilot your ships safely toward
Speaker 1: its destination. This is particularly useful during wart wartime, when
Speaker 1: you might have to worry about enemy ships patrolling certain
Speaker 1: areas of the seas and being able to navigate around them. Now,
Speaker 1: the theory behind Lauren was solid. The math works. The
Speaker 1: trick then was to make it a practical technology. Knowing
Speaker 1: that the theory was sound was one thing, but to
Speaker 1: put it into practice to actually build stuff that could
Speaker 1: use it. That was another and that presented a bit
Speaker 1: of a challenge. If the committee could find a way
Speaker 1: to synchronize transmissions from radio towers hundreds of miles apart,
Speaker 1: the scheme would work. But that synchronization was absolutely critical
Speaker 1: because without it, the difference in time between the two
Speaker 1: signals would be meaningless. The receiver would have no way
Speaker 1: of knowing the relationship between time and distance if the
Speaker 1: two sets of signals weren't sent out at exactly the
Speaker 1: same time. The team requested about four hundred thousand dollars
Speaker 1: worth of equipment on December uh well in December, in
Speaker 1: order to carry out an experimental run to determine if
Speaker 1: the mathematically attractive solution was actually feasible in the real world.
Speaker 1: And if we just that four hundred thousand dollars for inflation,
Speaker 1: that would be about seven point two million dollars worth
Speaker 1: of stuff in today's money. The team looked for suitable
Speaker 1: spots to construct the transmission towers, and at first they
Speaker 1: they considered some mountain peaks along the coast, but then
Speaker 1: they found two former Coastguard lifeboat stations that had fallen
Speaker 1: into disuse. One was outside Montauk Point, Long Island and
Speaker 1: the other off of Fenwick Island, Delaware. The two locations
Speaker 1: were two d nine nautical miles apart from one another,
Speaker 1: and they weren't too far from the headquarters for the project,
Speaker 1: which was in the Bell Telephone Laboratories in New York.
Speaker 1: The earliest tests concentrated not on synchronization, which was an
Speaker 1: area that Alfred Lee Loomis was particularly intrigued by as
Speaker 1: he had a fascination with timekeeping, but rather in how
Speaker 1: far they could broadcast the radio signals. They tried several
Speaker 1: different wavelengths to see which ones could perform best under
Speaker 1: different situations, and they discovered that longer wave length radio
Speaker 1: waves seemed to travel further at night, and shorter ones
Speaker 1: seemed to travel further during daylight hours, and that kind
Speaker 1: of suggested to them that maybe they should compromise and
Speaker 1: go with a medium wave length signal that would perform
Speaker 1: the best under most circumstances. They also did not test
Speaker 1: it with a ship at sea at first. Rather, they
Speaker 1: created a Loran receiver and they mounted it aboard a
Speaker 1: humble station wagon that traveled as far away as Springfield, Missouri.
Speaker 1: Now I have to say more about the development of
Speaker 1: Lauren in just a second, but first let's take another
Speaker 1: quick break to thank our sponsor. As work continued on
Speaker 1: the lor End project, the group began to work on
Speaker 1: a way to synchronize signals, because without synchronization, these equations
Speaker 1: are not going to create an accurate hyperbola. The solution
Speaker 1: was called a two trace indicator technique. A trace is
Speaker 1: a type of log or record of events. A common
Speaker 1: reference time acts as the anchor point for the traces,
Speaker 1: which can then be analyzed against each other to determine
Speaker 1: how close to synchronicity the two transmitters are and adjustments
Speaker 1: can be made. Eventually, they created a time keeping algorithm
Speaker 1: that was accurate enough that were in a wrist watch,
Speaker 1: you could go for a full decade without losing a
Speaker 1: minute on it. By January ninety two, the project was
Speaker 1: able to create a system that had an average error
Speaker 1: in the line of position of about two and a
Speaker 1: half miles or around four kilometers, which sounds like an
Speaker 1: awful lot, but when you're thinking about the distances that
Speaker 1: these various craft were traveling, it was actually pretty good.
Speaker 1: The remaining challenge was one that was solved relatively easily,
Speaker 1: The problem was the receivers would pick up two signals
Speaker 1: of different amplitudes, meaning different strength of signal, and the
Speaker 1: difference in amplitudes made it more difficult to measure the
Speaker 1: time difference between the signals accurately. So to fix this,
Speaker 1: the team built in differential gain control to help boost
Speaker 1: a low signal or dampen a powerful one, so that
Speaker 1: the calculations could be made more easily. Successful tests with
Speaker 1: ships and blimps convinced the U. S. Army and Navy
Speaker 1: to fund the construction of transmission stations for a larger
Speaker 1: tests in the Northwest Atlantic in nineteen two. Work continued
Speaker 1: in America, Canada, and Greenland to build out transmission stations.
Speaker 1: The project was a success, and work soon extended to
Speaker 1: other parts of the coast, as well as over in
Speaker 1: the UK. The application proved to be a sound one.
Speaker 1: Advancements in receiver technology allowed aircraft to use the same
Speaker 1: system a little bit later, which became incredibly useful during
Speaker 1: the war. Planes and ships could meet at rendezvous points
Speaker 1: that previously have been would have been impossible to achieve.
Speaker 1: Uh they were able to pair together different navigation systems,
Speaker 1: some of them were more accurate at closer ranges, and
Speaker 1: Lauren was more accurate at long range, so using the
Speaker 1: two together was really helpful. By the end of n
Speaker 1: more than three thousand naval ships and thirty thousand planes
Speaker 1: had Laura end technology aboard. After the war, the system
Speaker 1: was recognized as being so useful as to be instrumental
Speaker 1: in the shipping industry moving forward, and the US Coast
Speaker 1: Guard even produced a short film to convince shipping companies
Speaker 1: to adopt Lauren technologies for the purposes of navigation. Lauren
Speaker 1: stations were manned by military personnel, primarily the Coastguard. Now
Speaker 1: according to the Coastguard blog site, an assignment to a
Speaker 1: lur End station could be pretty lonesome. The crews tended
Speaker 1: to range in size between eight and twenty five people,
Speaker 1: and typically the person put in charge was a junior
Speaker 1: officer who had maybe served a tour of duty aboard
Speaker 1: a ship and now was put in charge of an office,
Speaker 1: and frequently this would be the highest military officer rank
Speaker 1: in the area, not meaning that the rank was particular
Speaker 1: really high, but rather that these stations were in pretty
Speaker 1: remote spaces, sometimes so much so that the only communication
Speaker 1: you had with the outside world was the radio and
Speaker 1: frequently you had to have all your supplies shipped to
Speaker 1: you on a regular basis. In fact, the blog post
Speaker 1: said that for a lot of these people, the day
Speaker 1: when a shipment came in would be a really big
Speaker 1: day if you were on if you're posted to one
Speaker 1: of these places, because you would actually get to speak
Speaker 1: to people who weren't on your crew, and that could
Speaker 1: be a real relief. Just imagine spending time was set
Speaker 1: up to seven to twenty four other people, and those
Speaker 1: are the only people you ever get to see. Ever,
Speaker 1: on top of that, the junior officers sometimes had to
Speaker 1: act as a representative of the US military and uh
Speaker 1: two people who were native to the areas that they
Speaker 1: were stationed in. So in some cases it wasn't so
Speaker 1: remote that you didn't have other people around you, but
Speaker 1: it was in a territory that did not belong the
Speaker 1: United States, and there you are as an official of
Speaker 1: the U. S Military, and you have to, you know,
Speaker 1: serve as a representative of your country. So that put
Speaker 1: a lot of extra pressure on you. It was pretty interesting. Now.
Speaker 1: On a blog post for the Coast Guard, Lieutenant Connie
Speaker 1: Brish said that a typical description of a tour of
Speaker 1: duty at a Lorentz station would be quote hours of
Speaker 1: boredom punctuated by moments of sheer panic end quote. Now,
Speaker 1: the staff's primary function was to make sure that the
Speaker 1: transmitters were working properly. That required standing watches, in which
Speaker 1: staff would literally remain in the room monitoring the equipment
Speaker 1: for the transmitter to verify that everything was still working
Speaker 1: as planned. It wasn't until a more advanced of Lauren
Speaker 1: called Lauren C automated enough of the functions to remove
Speaker 1: that necessity, and Laurence would not see wide deployment in
Speaker 1: the UH in the consumer world, especially until the nineteen seventies. Now,
Speaker 1: the original No Lauran system was later called Lauren A.
Speaker 1: Lauren B was the designation of a different version of
Speaker 1: Lauren which used the phase of the signals as the
Speaker 1: means of measuring time differences between the two received signals
Speaker 1: rather than comparing the actual timing of the pulse envelopes themselves. So,
Speaker 1: in other words, the original version of Lauren was all
Speaker 1: about when did this set of signals get to you?
Speaker 1: When did this pulse arrive to your receiver, and how
Speaker 1: does that compare to when this second pulse arrived to
Speaker 1: your receiver. It was just based upon that the order
Speaker 1: of operations of when a pulse of signals arrived to you.
Speaker 1: Lauren B was more about the phase of the signals
Speaker 1: and using that to determine the time difference as opposed
Speaker 1: to just this signal got to me first, and that
Speaker 1: actually improved the accuracy of Lauren in many ways. The
Speaker 1: United States Air Force was experimenting with a variation of
Speaker 1: Lauren C Lauren C, which also fall the approach that
Speaker 1: Lauren B was attempting to make. Lauren B never really
Speaker 1: got to see much use. It was kind of phased
Speaker 1: out pretty quickly, and Laurence took its place. Uh. Laurence
Speaker 1: used that same approach. And then there was a variation
Speaker 1: of Lauren C from the United States Airforce called Lauren
Speaker 1: D that was used as a means to create guidance
Speaker 1: systems for the military and actually saw some limited use
Speaker 1: in the Vietnam War. And Motorola introduced a navigational system
Speaker 1: that was not directly related to the other Laurens systems,
Speaker 1: but because it used a pulse chain technology, it ended
Speaker 1: up getting the nickname Lauren F, though again it wasn't
Speaker 1: really connected to the other versions of Lauren. While Laurence
Speaker 1: was superior to Lauren A, it was also more expensive
Speaker 1: to implement. It was more expensive to buy the receivers
Speaker 1: and install them on your equipment, so not everyone immediately
Speaker 1: switched over to Lauren C. Some people said, well, Lauren
Speaker 1: A works just fine and the system is still in place.
Speaker 1: Both systems are working together or at least concurrently, so
Speaker 1: I don't have to switch over. The companies that did
Speaker 1: make the switch would frequently offload their old Lauren A equipment,
Speaker 1: making Lauren A readily available and relatively inexpensive, which extended
Speaker 1: its useful life quite a bit. The Coast Guard eventually
Speaker 1: chose to discontinue Lauren A in all but a few
Speaker 1: spots in the world in the late nineteen seventies and
Speaker 1: early nineteen eighties, kind of forcing a switch over to
Speaker 1: Lauren C, And that was largely from an administrative standpoint.
Speaker 1: You wanted to have something that was more automated and
Speaker 1: you didn't have to dedicate as much staff to actually
Speaker 1: manning these stations. A different technology eventually began to displace
Speaker 1: Lauren altogether, and that was the Global Positioning System, or GPS.
Speaker 1: Through the use of satellites in orbit, it became possible
Speaker 1: to determine one's position on the planet with pretty good accuracy.
Speaker 1: But until the year two thousand, the GPS approach had
Speaker 1: a built in limitation designed to keep accurate information out
Speaker 1: of the hands of people who might use it to
Speaker 1: harm the United States. And this was called selective availability,
Speaker 1: and it would introduce time varying errors on purpose to
Speaker 1: reduce the accuracy of signals to about a hundred meters
Speaker 1: if you were using civilian GPS. If you had military GPS,
Speaker 1: this selective availability was not active. The whole selective availability
Speaker 1: purpose was to prevent bad actors from being able to
Speaker 1: use GPS to hone in on sensitive US sites like
Speaker 1: military bases. And in two thousand, President Bill Clinton signed
Speaker 1: an agreement that turned off selective availability and reduced the
Speaker 1: introduced errors to zero, meaning that you no longer had
Speaker 1: any purposeful time varying errors inserted into the GPS signals,
Speaker 1: giving citizens the opportunity to receive much more accurate GPS
Speaker 1: readings and making stuff like real time mapping apps possible
Speaker 1: because imagine using a real time mapping app and it's
Speaker 1: still got the selective availability uh turned on and so
Speaker 1: you know that sometime within a hundred meters you need
Speaker 1: to turn right, but you aren't exactly sure where. It
Speaker 1: might be a hundred meters ahead of you, might be
Speaker 1: a hundred meters behind you, it might be somewhere within
Speaker 1: that range, and you don't know if you've passed the
Speaker 1: street already or not. Obviously, that would limit the usefulness
Speaker 1: of GPS, but because we got rid of selective availability
Speaker 1: in two thousand, we now can use apps that rely
Speaker 1: on GPS that are far more accurate to just a
Speaker 1: couple of meters. GPS became ubiquitous rapidly, and Loran was
Speaker 1: phased out over time, but there has been talk of
Speaker 1: developing a new LORAN system called e Loran or Enhanced Lauren.
Speaker 1: That version would allow for a positional system accurate to
Speaker 1: within eight meters, making it a potential backup should GPS
Speaker 1: fail or should people try to block or jam GPS signals.
Speaker 1: There's been reported GPS interference over the Black Sea, and
Speaker 1: there's been reported GPS blocking UH technologies around North Korea,
Speaker 1: so this would be a way of getting around that.
Speaker 1: You could not block it in the same way that
Speaker 1: you would with GPS signals. The UK went so far
Speaker 1: as to allocate resources to building out such a system,
Speaker 1: though the government would eventually reverse that decision in two
Speaker 1: thousand fifteen after France and Norway ended their Laura and transmissions.
Speaker 1: And that's the story of Lauren, the really important technology
Speaker 1: overseen by the Microwave Committee and then the Radiation Laboratory
Speaker 1: of m T, which in turn was reporting to Alfred Lee. Loomis,
Speaker 1: the guy I talked about last week, and I thought
Speaker 1: it was pretty fascinating. I love watching the videos of
Speaker 1: how this technology worked and the actual way of plotting
Speaker 1: where you were on the map. It was a pretty
Speaker 1: fascinating use of mathematics and technology. So I highly recommend
Speaker 1: you go check out some of those videos so that
Speaker 1: you can get a visualization on what I've been chatting about.
Speaker 1: It's pretty fascinating stuff. If any of you have any
Speaker 1: suggestions for future episodes of tech Stuff, maybe it's a technology,
Speaker 1: maybe it's a company, maybe it's a person in tech
Speaker 1: I should talk about, you should send me those suggestions. Likewise,
Speaker 1: if you think of someone I should interview or have
Speaker 1: on as a guest, let me know. Send me an email.
Speaker 1: The addresses tech Stuff at how stuff Works dot com
Speaker 1: or draw me a line on Facebook or Twitter. The
Speaker 1: handle of both of those is tech stuff hs W.
Speaker 1: You can follow me on Instagram just look for the
Speaker 1: tech stuff account over there and you can check that
Speaker 1: out as well. And remember I broadcast live on Wednesdays
Speaker 1: and Fridays at twitch dot tv slash tech stuff. You
Speaker 1: can watch me record these shows live and in person.
Speaker 1: There's a chat room you can join in on and
Speaker 1: I would love to see you in there, and I
Speaker 1: will talk to you again really soon. For more on
Speaker 1: this and thousands of other topics. Is that how stuff
Speaker 1: works dot com eight