WEBVTT - The Future of Radar 0:00:00.160 --> 0:00:07.080 Brought to you by Toyota. Let's go places. Welcome to 0:00:07.280 --> 0:00:13.360 Forward Thinking. Hey, they're and welcome to Forward Thinking, the 0:00:13.520 --> 0:00:15.720 podcast that looks at the future and says I was 0:00:15.760 --> 0:00:18.720 seriously thinking about hiding the receiver when the switch broke 0:00:18.840 --> 0:00:23.320 because it's old. I'm Jonathan Strickland and I'm Joe McCormick. 0:00:23.600 --> 0:00:28.360 And today we're going to be talking about radar, right 0:00:29.160 --> 0:00:32.680 and uh. And and just for our fans who are 0:00:32.680 --> 0:00:35.240 my age or older, we're not talking about the popular 0:00:35.360 --> 0:00:39.879 character from the movie and television series Mash unfortunately not. 0:00:40.280 --> 0:00:43.519 Now we're talking about the actual technology radar, which is 0:00:44.040 --> 0:00:47.320 nothing new. No, it's it's it's been around for quite 0:00:47.320 --> 0:00:49.919 a few decades. But it's super cool. There's a lot 0:00:49.920 --> 0:00:53.080 of different applications for it that are really interesting, and 0:00:53.120 --> 0:00:55.920 apparently there are going to be some new applications for 0:00:56.000 --> 0:00:58.560 it in the future. Yeah, and even if there is 0:00:58.600 --> 0:01:03.840 a future, well, it's on my radar. Uh, it's gonna happen. 0:01:03.960 --> 0:01:05.520 Might as well get it all the way early. The 0:01:06.240 --> 0:01:08.880 neat thing is the way that the technology is is 0:01:08.959 --> 0:01:12.480 changing over time. Like there it's being married with other technologies. 0:01:12.480 --> 0:01:15.119 But we'll get into that, Okay, Well, let me. Let 0:01:15.120 --> 0:01:18.920 me explore the layman's view of radar. What is radar 0:01:19.319 --> 0:01:22.800 If you don't know, it has something to do with 0:01:22.840 --> 0:01:26.600 a circular screen that has a line that sweeps around 0:01:26.680 --> 0:01:31.880 it and goes you've mistaken ever sonar? Oh no, wait, 0:01:31.920 --> 0:01:34.640 hold on, hold on. It has something to do with 0:01:35.120 --> 0:01:38.080 like a little antenna that spins around really fast. Yeah, 0:01:38.120 --> 0:01:41.319 that's that's closer, and there can be around around screen. 0:01:41.400 --> 0:01:44.319 It's just the bloop is totally indicative of sonar ups 0:01:44.319 --> 0:01:47.880 as opposed to radar. You could make a radar display. 0:01:47.920 --> 0:01:53.520 Bloop could incredible. Future looking is one of the easiest 0:01:53.520 --> 0:01:57.800 things to program. Look, I've I've I've studied screenplays, and 0:01:57.880 --> 0:02:00.200 I realized that if you make it blue, you have 0:02:00.280 --> 0:02:04.160 confused your audience. So but no. The other interesting thing 0:02:04.160 --> 0:02:05.680 that we want to talk about before we actually get 0:02:05.680 --> 0:02:08.520 into what radar is now it works is the fact 0:02:08.520 --> 0:02:10.120 that it used to be an acronym and now it's 0:02:10.120 --> 0:02:12.840 not anymore. It's one of those words like laser, laser 0:02:12.919 --> 0:02:15.440 was like this wasn't it? Sure was? Yeah, so it 0:02:15.600 --> 0:02:18.040 used to be. It used to stand for something and 0:02:19.880 --> 0:02:22.760 won't stand. You could walk into them. The President of 0:02:22.800 --> 0:02:24.959 the United States could walk into our room. Radar is 0:02:24.960 --> 0:02:27.280 not gonna get up right, It's just like it's just 0:02:27.360 --> 0:02:29.880 a lowercase word. You don't even capitalize it. What did 0:02:29.960 --> 0:02:34.040 it originally stand for? Radio detection and ranging. That's what 0:02:34.080 --> 0:02:37.200 the United States Navy referred to it and the r 0:02:37.320 --> 0:02:40.400 A of radio were capitalized because it wasn't in the 0:02:40.440 --> 0:02:42.919 day when they would just add extra random words and there, 0:02:42.960 --> 0:02:44.680 and they didn't to make the really cool Yeah, they 0:02:44.680 --> 0:02:47.720 didn't want and they didn't want to call it nar. Yeah, 0:02:47.840 --> 0:02:52.799 so so turn on the dar. Yeah that did not 0:02:52.960 --> 0:02:55.800 That did not fly. So they went with radar. But 0:02:55.919 --> 0:02:59.119 today it's just radar. It's just a little lowercase word 0:02:59.240 --> 0:03:02.200 radar because we we say it so much, you know. 0:03:03.080 --> 0:03:05.480 I mean, boy, if I had a nickel for every 0:03:05.520 --> 0:03:08.120 time I talked about radar in your average week. Well, 0:03:08.200 --> 0:03:12.079 let's explain how radar actually works. It's actually a pretty 0:03:12.120 --> 0:03:17.120 simple principle. Yeah, it's actually very similar to echolocation, right, 0:03:17.200 --> 0:03:19.120 It's it's based on a very so and and in 0:03:19.160 --> 0:03:22.320 fact sonar it's it's based on similar principles, except in 0:03:22.360 --> 0:03:24.320 stuff of sound. We're talking about radio waves, which by 0:03:24.320 --> 0:03:26.760 the way, don't work so well underwater, but they were 0:03:26.919 --> 0:03:31.200 great above water. So, uh, Essentially, what you're doing is 0:03:31.240 --> 0:03:34.640 you're sending out bursts of radio waves or microwaves, like 0:03:34.720 --> 0:03:39.560 we're talking super short bursts, like microsecond long bursts. And 0:03:39.680 --> 0:03:43.880 you do that often whatever direction you're looking at, and 0:03:44.080 --> 0:03:48.240 if those waves encounter and object, some of them will 0:03:48.280 --> 0:03:52.280 bounce back towards the source of the transmission. So you've 0:03:52.280 --> 0:03:54.400 got to You've got transmitter and the receiver. You turn 0:03:54.440 --> 0:03:58.080 on the transmitter, you send out a blast of radio waves, 0:03:58.080 --> 0:04:00.560 you switch off the transmitter, you turn on the receiver, 0:04:01.440 --> 0:04:05.000 and when those returning waves come back one, you know 0:04:05.080 --> 0:04:08.160 that there's an object out there that the waves have encountered. 0:04:08.200 --> 0:04:10.280 And too, you know how far away it is because 0:04:10.640 --> 0:04:13.840 you can measure the time it took from when the 0:04:13.960 --> 0:04:16.240 radio waves went out of the antenna to when the 0:04:16.320 --> 0:04:20.159 echo came back in, and beyond that, you can actually 0:04:20.160 --> 0:04:22.360 tell whether or not the object is moving towards you 0:04:22.440 --> 0:04:27.359 or away from you using the Doppler shift, right, the 0:04:27.400 --> 0:04:32.000 Doppler effect that we're all familiar with from hearing police sirens. Yeah, 0:04:32.600 --> 0:04:36.039 so when you hear a police siren approaching you, it's 0:04:36.160 --> 0:04:38.919 it's getting this high pitch noise. It gets higher and 0:04:39.000 --> 0:04:42.440 higher and then after it passes you, you know that, yeah, 0:04:42.640 --> 0:04:45.840 suddenly gets lower, right, And the reason it does that 0:04:45.880 --> 0:04:49.120 the Doppler effect applies to all waves. It's not just 0:04:49.200 --> 0:04:53.000 sound waves, it's also radio waves. And what's happening is 0:04:53.120 --> 0:04:57.320 essentially those waves are being compressed ahead of the moving 0:04:57.360 --> 0:05:00.080 object when it's coming towards you, so the frequen s 0:05:00.320 --> 0:05:03.120 is increased. And when the frequency increases with sound, that 0:05:03.160 --> 0:05:06.600 means the pitch goes up right, And when the object 0:05:06.680 --> 0:05:11.080 passes by you, then the waves are being elongated. So 0:05:11.279 --> 0:05:14.080 now the pitch has decreased, it's gone down. And if 0:05:14.120 --> 0:05:16.960 you were standing right next to the to a stationary 0:05:16.960 --> 0:05:19.520 police vehicle while it was having the siren go off, 0:05:19.720 --> 0:05:22.960 it would sound in between those two well relatively speaking. Yeah. 0:05:22.960 --> 0:05:25.680 And in fact, you can even observe this with visible light, 0:05:25.800 --> 0:05:30.520 say like in astronomy, the disena moving away from us 0:05:30.560 --> 0:05:32.839 faster and faster in the galaxy or in the universe 0:05:32.839 --> 0:05:35.000 are going to be red shifted. Right. And in fact, 0:05:35.040 --> 0:05:39.159 also this is really part of what sonic booms. You know, 0:05:39.200 --> 0:05:41.200 why we have a sonic boom. If you're if you 0:05:41.240 --> 0:05:43.400 have an object that's moving faster than the speed of 0:05:43.440 --> 0:05:46.000 sound at whatever altitude you happen to be at. Because 0:05:46.120 --> 0:05:49.680 sound speed depends upon the medium it's traveling through, and 0:05:49.839 --> 0:05:52.760 with atmosphere, it could be affected by lots of stuff 0:05:52.760 --> 0:05:55.760 like humidity, the air density, the temperature, all that kind 0:05:55.800 --> 0:05:58.599 of thing. But anyway, if we're talking about something moving 0:05:59.040 --> 0:06:01.880 faster than the speed of sound, all of those sound 0:06:01.920 --> 0:06:07.960 waves get compressed so so flat that if you're in 0:06:08.120 --> 0:06:10.440 front of that object and it's coming towards you, you're 0:06:10.480 --> 0:06:13.400 not going to hear anything. You might, yeah, you might 0:06:13.440 --> 0:06:16.960 say what's that before it gets past you, And once 0:06:16.960 --> 0:06:18.840 it gets past you, then essentially all that sound is 0:06:18.920 --> 0:06:22.800 unleashed and a catch us up, glorious boom of fury 0:06:23.080 --> 0:06:25.560 and then and that's where the sonic boom comes in. 0:06:25.640 --> 0:06:28.160 And actually the sonic boom rolls along as long as 0:06:28.200 --> 0:06:31.240 the object continues to move faster than the speed of sound. Now, 0:06:31.240 --> 0:06:34.120 with radio waves, we don't get the sonic boom because 0:06:34.200 --> 0:06:37.200 we're talking about radio frequencies, we're not talking about acoustic waves. 0:06:38.080 --> 0:06:41.360 But what we can see is that if the frequency 0:06:41.480 --> 0:06:44.800 of the returning echo is greater than that what we 0:06:45.000 --> 0:06:47.080 than the frequency we sent out, then we know the 0:06:47.120 --> 0:06:50.320 object that we're looking at is moving toward us. If 0:06:50.360 --> 0:06:52.919 the frequency is less than what we sent out, we 0:06:52.960 --> 0:06:55.200 know the object is moving away from us. And by 0:06:55.200 --> 0:06:57.760 sending out series of these signals, we can tell in 0:06:57.880 --> 0:07:01.400 what direction and at what speed the object is moving exactly. 0:07:01.480 --> 0:07:04.560 And because each of these verses like a microsecond in length, here, 0:07:04.600 --> 0:07:06.760 you can you know, you can do this several times 0:07:07.040 --> 0:07:09.520 a minute, you know, depending upon what your system is 0:07:09.520 --> 0:07:13.040 looking for and uh and how you're focusing on that 0:07:13.080 --> 0:07:18.840 particular section of sky. Usually yeah, and so if I 0:07:18.880 --> 0:07:22.480 remember correctly, you'll probably be able to tell me mostly 0:07:22.600 --> 0:07:25.520 radar is going to be operating in the microwave frequency 0:07:25.600 --> 0:07:28.880 of the e M spectrum. That's that's largely what we 0:07:29.000 --> 0:07:32.160 see today. A lot of radio radar works in the microwaves, 0:07:32.200 --> 0:07:34.880 but it can't work in other other parts of the 0:07:35.600 --> 0:07:38.240 electromagnetic spectrum. And I think originally a lot of it 0:07:38.320 --> 0:07:41.640 was in radio. Yeah, right, so that would be yeah, yeah, 0:07:41.640 --> 0:07:44.160 So if you imagine the the e M spectrum, like 0:07:44.200 --> 0:07:47.520 you've got the longer wavelengths than visible light or microwaves, 0:07:47.520 --> 0:07:49.800 and then even longer than that or what we usually 0:07:49.800 --> 0:07:54.840 call radio waves. So yeah, and and the frequency would 0:07:54.840 --> 0:07:57.840 be you know, the greater the frequency, the greater the 0:07:57.840 --> 0:07:59.760 amount of information we can get back, which is why 0:07:59.800 --> 0:08:01.960 you want to use higher frequencies if you can. But 0:08:01.960 --> 0:08:04.040 we'll get into that later, which is part of why 0:08:04.080 --> 0:08:06.920 we talked so much about microwaves in another episode. We 0:08:07.080 --> 0:08:09.040 wait a minute, if you can get more information from 0:08:09.080 --> 0:08:12.880 higher frequency, why don't we just use gamma rays. Well, 0:08:13.480 --> 0:08:16.240 there are a lot of reasons why. One is that 0:08:16.320 --> 0:08:22.120 we don't want a lot of incredible hulks running around. Yeah. Well, uh, 0:08:22.160 --> 0:08:25.920 you know, honestly, obviously, gamma radiation would be inably dangerous, 0:08:25.920 --> 0:08:28.760 even if we could generate it easily without pouring tons 0:08:28.800 --> 0:08:31.920 of energy into whatever system we had created to make gama. 0:08:32.360 --> 0:08:34.320 That was my guess. Is just that it's harder to 0:08:34.360 --> 0:08:38.040 make and that it would also kill you. Yeah, the 0:08:38.480 --> 0:08:41.600 two combined are really good reasons why we don't go 0:08:41.640 --> 0:08:45.080 into it. Okay, Well, let's look back at the sort 0:08:45.120 --> 0:08:48.400 of the early days of radar, the juvenilia of radar, 0:08:49.360 --> 0:08:51.200 well back when radar was just a gleam in a 0:08:51.200 --> 0:08:54.520 bunch of engineers eyes. The you gotta look at the 0:08:54.559 --> 0:08:56.720 beginning of the twentieth century. So a lot of the 0:08:56.720 --> 0:08:59.360 groundwork was laid in the nineteenth century, where you had 0:08:59.640 --> 0:09:04.080 people discovering and experimenting with radio waves, but it wasn't 0:09:04.160 --> 0:09:06.800 until the early twentieth century that we started seeing people 0:09:06.960 --> 0:09:09.120 figure out, oh, we might be able to use this 0:09:09.160 --> 0:09:13.160 in order to detect things. Uh. There was an engineer 0:09:13.240 --> 0:09:16.240 in Christian hulls Meyer who invented a system that allowed 0:09:16.240 --> 0:09:20.120 ships or trains to avoid collisions on foggy days. Uh. 0:09:20.160 --> 0:09:22.880 The uh, the source I was reading, which was the 0:09:22.960 --> 0:09:27.439 APS Physics website, referred to it as crude. In other words, 0:09:27.440 --> 0:09:30.280 it was not a very refined system. Sure, but but 0:09:30.360 --> 0:09:33.240 you can immediately see or not see. Is the case? 0:09:33.320 --> 0:09:38.120 Maybe the benefit that radio waves have over electromagnetic light 0:09:38.160 --> 0:09:43.000 waves well sorry, visible spectrum, sure waves on a foggy day, 0:09:43.120 --> 0:09:46.240 because you can't see through fog, right, Yeah, you have 0:09:46.320 --> 0:09:48.400 radio waves can bounce right through if light is going 0:09:48.440 --> 0:09:50.520 to be reflected off the fog bank ahead of you, 0:09:50.559 --> 0:09:53.880 it doesn't. You can't really count on that being an 0:09:53.920 --> 0:09:56.959 effective signal to any other vehicles. So yeah, it was 0:09:57.000 --> 0:09:59.480 certainly something that was useful. The U. S. Navy had 0:09:59.520 --> 0:10:02.120 begun to a experiment with radar, although it wasn't called 0:10:02.120 --> 0:10:05.800 that at the time, to search for ships. But actually 0:10:05.800 --> 0:10:08.640 that research was largely overlooked in the United States, Like 0:10:08.679 --> 0:10:10.960 it was a group of researchers within the Navy that 0:10:11.000 --> 0:10:14.280 was doing a lot of this work, but because it 0:10:14.360 --> 0:10:17.760 was viewed as experimental, it wasn't thought of as particularly 0:10:17.840 --> 0:10:20.360 practical at that time. So it's kind of like they 0:10:20.360 --> 0:10:21.960 were left to do their own thing, and no one 0:10:22.040 --> 0:10:24.040 was really thinking it would ever come to anything. But 0:10:24.120 --> 0:10:27.640 that's amazing because it seems so clear to us now 0:10:27.760 --> 0:10:31.960 how useful something like radar is in warfare, Like you 0:10:32.000 --> 0:10:35.000 can have real time updates about the position of enemy 0:10:35.080 --> 0:10:39.400 vehicles in the moment, you know, as soon as they're 0:10:39.440 --> 0:10:42.199 advancing on you. You can see them in long distances well, 0:10:42.320 --> 0:10:46.080 especially things like aircraft, which would be particularly useful. And 0:10:46.160 --> 0:10:49.319 in fact, over in the UK research was going on, 0:10:49.960 --> 0:10:52.960 you know, in various places, but largely we have to 0:10:52.960 --> 0:10:57.480 thank Sir Robert Watson What, who was actually a descendant, 0:10:58.200 --> 0:11:02.440 a relative and distant relative of of the famous what 0:11:02.440 --> 0:11:06.160 What did all the steam engines at any rate? Uh So, 0:11:06.200 --> 0:11:09.520 Sir Robert Watson Watt began to work with radio waves 0:11:09.720 --> 0:11:13.040 um as a means of detecting aircraft, but first had 0:11:13.080 --> 0:11:16.160 been working in the Meteorological Office to develop systems to 0:11:16.240 --> 0:11:20.160 detect lightning strikes because lightning can give off radio waves. 0:11:20.200 --> 0:11:22.640 In fact, lightning strikes do give off radio waves, so 0:11:22.679 --> 0:11:25.600 if you have a detector, then you can start to 0:11:25.840 --> 0:11:29.160 detect thunderstorms, and that was considered to be very useful 0:11:29.400 --> 0:11:32.360 the UH, the United Kingdom at the time, wasn't really 0:11:32.520 --> 0:11:38.960 concerned with developing radio detection systems. But what happened was 0:11:39.280 --> 0:11:41.880 there was a rumor going around that the Germans had 0:11:41.880 --> 0:11:46.439 developed a death ray using radio waves, and so the 0:11:46.559 --> 0:11:51.480 UK government came to Watson. Watton said, if that's a thing, 0:11:51.920 --> 0:11:55.040 we're gonna need one of those. Can you even make 0:11:55.080 --> 0:11:57.360 one of those for us? And so he started looking 0:11:57.400 --> 0:12:00.600 into it, but very quickly he said, you know, there, 0:12:00.679 --> 0:12:03.680 this doesn't seem feasible at all from everything I've learned. 0:12:03.679 --> 0:12:07.200 That doesn't make sense. However, maybe we could focus on 0:12:07.360 --> 0:12:11.720 radio detection instead of radio destruction. And he really began 0:12:11.760 --> 0:12:15.360 to push for this means of using radio to bounce 0:12:15.440 --> 0:12:18.920 waves off of objects so that you can detect them remotely, 0:12:19.600 --> 0:12:22.960 and he got some support and it was very important 0:12:23.000 --> 0:12:24.680 in the UK at the time because we're talking about 0:12:24.720 --> 0:12:27.960 getting into World War two and the UK was heavily 0:12:28.000 --> 0:12:33.839 involved and obviously the fears of Germans German aircraft coming 0:12:33.840 --> 0:12:41.760 over and bombing England were warranted, so they the ability 0:12:41.760 --> 0:12:43.480 to get people out of an area when they saw 0:12:43.640 --> 0:12:49.160 when they saw craft coming huge absolutely necessary. Yeah. Funny 0:12:49.240 --> 0:12:52.400 side note to this, This is actually sort of related 0:12:52.679 --> 0:12:57.360 to the myth that carrots give you super eyesight. Did 0:12:57.400 --> 0:13:00.200 you know this? I wrote a brain Stuff episode about this. 0:13:00.760 --> 0:13:04.960 It's a fascinating little historical blip. So yeah, Apparently one 0:13:05.000 --> 0:13:07.840 of the reasons that the British Royal Air Force was 0:13:07.920 --> 0:13:13.240 pretty successful in repelling UH access air raids against the 0:13:13.240 --> 0:13:17.160 British was that they had on board radar. So like 0:13:17.240 --> 0:13:20.679 these these planes were equipped with you know, radar systems 0:13:20.679 --> 0:13:23.040 that could tell them when enemy aircraft were approaching from 0:13:23.080 --> 0:13:25.520 a very long distance. But of course they didn't want 0:13:25.520 --> 0:13:27.640 to let onto anything like that, so part of their 0:13:27.679 --> 0:13:31.360 misinformation campaign. Yeah, well, I think that's one theory. Other 0:13:31.400 --> 0:13:34.559 people have different explanations for why they said this, but 0:13:35.400 --> 0:13:38.360 for whatever reason, the British government said, you know, the 0:13:38.360 --> 0:13:40.880 reason our pilots can see so well is because they 0:13:40.880 --> 0:13:44.600 eat lots of vegetables rich in vitamin A like carrots. 0:13:45.280 --> 0:13:48.480 So at the same time, of course they were trying 0:13:48.480 --> 0:13:51.040 to get people to eat carrots because that was like 0:13:51.080 --> 0:13:52.760 one of the you know, one of the foods, one 0:13:52.800 --> 0:13:55.480 of the few foods that was plentiful in England at 0:13:55.480 --> 0:13:58.720 the time, to and to grow victory gardens quote unquote 0:13:58.760 --> 0:14:02.640 victory gardens that in which carrots were quite easy to grow. Right, 0:14:03.320 --> 0:14:06.360 that's interesting, Yeah, oh well, you know, but so it 0:14:06.400 --> 0:14:08.360 turns out it was a lie, you know, the pilots 0:14:08.679 --> 0:14:13.000 suggesting that they just had super keen eye sight. At 0:14:13.040 --> 0:14:16.439 the same time, vitamin A is very important for maintaining normal, 0:14:16.559 --> 0:14:21.200 healthy eye sight. So so we eat your carrots, kid. Well. Meanwhile, 0:14:21.240 --> 0:14:24.160 going back over to the United States, during the same time, 0:14:24.200 --> 0:14:28.080 the Navy continued to develop radar and in fact named 0:14:28.120 --> 0:14:31.280 it such, creating the first US radar and it was 0:14:31.320 --> 0:14:33.640 called the x A F. It was installed on the 0:14:33.760 --> 0:14:37.040 U s S New York battleship in nineteen thirty nine. 0:14:38.000 --> 0:14:41.520 So obviously the earliest uses of radar were in military applications, 0:14:41.760 --> 0:14:43.520 and that's not a huge surprise, I mean it was 0:14:43.560 --> 0:14:47.560 that was where it was very much useful. But shortly thereafter, 0:14:47.720 --> 0:14:50.880 once the war ended, we started to see radar get 0:14:50.960 --> 0:14:53.840 used in lots of different applications, including a lot of 0:14:53.880 --> 0:14:58.680 commercial ones, so air traffic control aboard aircraft itself, like 0:14:58.680 --> 0:15:02.160 like you were saying jokes for commercial aircraft, not just um, 0:15:02.360 --> 0:15:08.480 military aircraft also uh, commercial ships, UM and other means 0:15:08.520 --> 0:15:11.200 as well. And and of course going back to what 0:15:11.400 --> 0:15:14.920 Watson Watt was originally studying, we began using it for 0:15:15.160 --> 0:15:18.560 weather detection, yeah, and forecasting. And this is uh, you know, 0:15:18.600 --> 0:15:21.360 like Doppler radar. You hear it all the time, especially 0:15:21.360 --> 0:15:24.360 here in Atlanta. Again they're so proud of their Doppler 0:15:24.480 --> 0:15:27.800 radar UM, but yeah, it's Doppler radar. Is is using 0:15:27.840 --> 0:15:31.760 the Doppler chef to detect moving weather patterns. And honestly, 0:15:31.840 --> 0:15:36.040 what they're mostly looking at is precipitation. So you know, 0:15:36.160 --> 0:15:40.800 the radar, the radio waves or microwaves will bounce back 0:15:40.880 --> 0:15:44.560 from precipitation telling you, oh, well there's a front moving 0:15:44.600 --> 0:15:46.720 in and we can keep track of it. We can 0:15:46.760 --> 0:15:49.360 even map out the shape of it. And so when 0:15:49.400 --> 0:15:53.880 you see the radar imagery that's based off the data 0:15:53.920 --> 0:15:57.280 that's coming back from that, that uh the signals which 0:15:57.320 --> 0:16:02.720 is pretty cool. Uh. The radar transmitters for Doppler radar 0:16:02.760 --> 0:16:06.680 for weather are pretty powerful. They use food watts of 0:16:06.720 --> 0:16:10.640 electricity when they're blasting out signals. I gotta be honest, 0:16:10.720 --> 0:16:12.840 I have no idea how much that is. A regular 0:16:12.880 --> 0:16:18.080 microwave oven is one thousand watts, So multiply a regular 0:16:18.160 --> 0:16:23.040 microwave oven four fifty times and you get what. But however, 0:16:23.680 --> 0:16:28.360 this particular radar technology isn't used, you know, It's not 0:16:28.400 --> 0:16:31.000 like they turn it on and it's blasting out radio 0:16:31.040 --> 0:16:33.880 waves for like hours at a time, right right, It's 0:16:33.960 --> 0:16:36.480 it's more like defrost mode on your microwave where it 0:16:36.520 --> 0:16:39.800 sends out kind of little blips and and then collects them. 0:16:39.840 --> 0:16:42.640 All right, It's it's to get a composite. It's spending 0:16:42.680 --> 0:16:45.520 most of its time listening rather than blasting. So it'll 0:16:45.520 --> 0:16:48.120 send out a blast of radio waves in a very 0:16:48.160 --> 0:16:50.600 short amount of time of fraction of a second, and 0:16:50.640 --> 0:16:52.920 then it listens for a good long while for the 0:16:52.960 --> 0:16:57.000 echoes to come back. So we're talking about um such 0:16:57.040 --> 0:16:59.040 a short amount of time that the source I've read 0:16:59.120 --> 0:17:03.600 said it transmits for about seven seconds in a typical hour. 0:17:04.280 --> 0:17:06.600 So it sounds like if they just leave this thing on, 0:17:06.800 --> 0:17:10.640 the army could have the death ray they wanted. Well, 0:17:10.680 --> 0:17:15.960 they could at least drain the power grid nothing else. Uh, 0:17:16.000 --> 0:17:19.159 I don't know that it would necessarily do anything else besides, um, 0:17:19.240 --> 0:17:22.520 you know it could it could probably jam communications with 0:17:22.600 --> 0:17:26.120 that many radio waves going out, but that'd be about it. Well. 0:17:26.160 --> 0:17:28.520 I mean, we used to think about radar as this 0:17:28.600 --> 0:17:32.879 kind of like high tech, expensive military technology, and it 0:17:33.040 --> 0:17:35.560 used to be that. Yeah, but but now you see 0:17:35.600 --> 0:17:38.000 it all over the place, right Yeah. Now it's actually 0:17:38.040 --> 0:17:41.600 making its way into consumer technology. So I mean, you know, 0:17:41.840 --> 0:17:44.000 it's not going to be in your smartphone, but it 0:17:44.080 --> 0:17:48.000 might be in your car yet. Yeah. So autonomous cars 0:17:48.040 --> 0:17:51.199 obviously need to have a lot of of sensors, right 0:17:51.280 --> 0:17:54.639 in order to to note what is in their particular 0:17:55.760 --> 0:17:58.240 neighborhood so that they know, you know, whether they can 0:17:58.280 --> 0:18:00.760 merge over, change lanes, speed up, slow down, that kind 0:18:00.760 --> 0:18:02.760 of thing, right, And you can use different kinds of 0:18:02.800 --> 0:18:05.120 waves to do this. For example, one thing we've seen 0:18:05.160 --> 0:18:08.359 employed a lot in autonomous cars is lidar, yeah, which 0:18:08.480 --> 0:18:12.240 is you know, it's laser oriented as opposed to using 0:18:12.760 --> 0:18:16.360 radio frequencies. But radar is also used. Uh. There are 0:18:16.440 --> 0:18:19.840 lots of different systems where radar is used to maintain 0:18:20.320 --> 0:18:24.000 a safe distance between the vehicle, the vehicle itself and 0:18:24.040 --> 0:18:26.880 any vehicles around it. So you know, like the rule 0:18:26.920 --> 0:18:29.000 of thomb being that if you're behind a vehicle, you 0:18:29.000 --> 0:18:32.639 should be able to count to three uh when it 0:18:32.680 --> 0:18:36.680 passes a landmark before you pass that landmark to Well, 0:18:36.760 --> 0:18:38.960 these kind of systems will make sure you maintain that 0:18:39.080 --> 0:18:42.320 safe distance at whatever operating speed the vehicle happens to 0:18:42.359 --> 0:18:45.360 be at. So yeah, and I think you you talk, 0:18:45.440 --> 0:18:47.080 you go into a little bit more detail about that 0:18:47.119 --> 0:18:51.200 one in the video version, yeah, our radar episode, right, Yeah, 0:18:51.200 --> 0:18:53.920 I specifically talk about dynamic cruise control, which is something 0:18:53.960 --> 0:18:56.000 that's kind of a it's like a stepping stone between 0:18:56.040 --> 0:18:59.199 the cars we have now and truly autonomous cars and 0:18:59.240 --> 0:19:03.080 a lot of vehicles right now have dynamic cruise control UM. 0:19:03.160 --> 0:19:06.600 And the basic principle is that you set the cruising 0:19:06.640 --> 0:19:09.560 speed of your vehicle, but it also has this radar 0:19:09.640 --> 0:19:12.480 system so it can maintain the proper distance between any 0:19:12.480 --> 0:19:14.200 cars in front of it, and if it starts to 0:19:14.280 --> 0:19:17.880 get past a certain threshold of safety, the system will 0:19:17.920 --> 0:19:20.600 automatically apply the brakes to slow down your vehicle, but 0:19:20.720 --> 0:19:23.199 you'll still be in cruise control so you don't have 0:19:23.280 --> 0:19:25.960 to hit Yeah, you don't have to hit a break 0:19:26.040 --> 0:19:28.119 or an accelerator to turn it off. You can just 0:19:28.280 --> 0:19:30.400 let it keep going. And you know, if traffic starts 0:19:30.440 --> 0:19:32.240 picking up, then obviously you would take it off of 0:19:32.240 --> 0:19:35.159 cruise control, but otherwise you just let it go. I 0:19:35.200 --> 0:19:37.840 think this is an interesting application of radar because if 0:19:37.880 --> 0:19:40.119 you look back at the history of it, what it 0:19:40.160 --> 0:19:42.920 was originally great for was seeing stuff that is very 0:19:42.960 --> 0:19:46.600 far away. You know, it's sort of like extending our 0:19:46.720 --> 0:19:49.520 vision beyond where we could where we can naturally ever 0:19:49.600 --> 0:19:52.720 hope to sense with our puny, little human senses. But 0:19:52.800 --> 0:19:58.920 now it's more about having cheap, controllable, short range options. 0:19:59.040 --> 0:20:02.880 Oh sure, especially in that consumer space, right Uh, seeing 0:20:02.960 --> 0:20:05.800 any kind of technology mature, we we tend to see 0:20:05.800 --> 0:20:08.480 this kind of approach, this kind of a pathway. You know, 0:20:08.560 --> 0:20:12.440 some technologies probably won't ever follow that pathway, just because 0:20:12.440 --> 0:20:14.879 either they'll never get inexpensive enough or there's not a 0:20:14.920 --> 0:20:18.240 practical consumer application for them. But this is one case 0:20:18.320 --> 0:20:22.920 where there is a practical application, So that's pretty cool. 0:20:22.920 --> 0:20:25.199 But there are other practical applications that are go a 0:20:25.200 --> 0:20:28.600 little beyond being in your vehicle, yeah, less on the 0:20:28.640 --> 0:20:31.760 consumer end. Other other cool stuff is happening in radar, 0:20:31.920 --> 0:20:44.360 for example, radar in space. Fu um so starting background, 0:20:45.280 --> 0:20:47.600 NASA in the e s A had teamed up and 0:20:47.680 --> 0:20:52.119 began launching synthetic aperture radar devices into orbit. Are we 0:20:52.160 --> 0:20:56.720 sure this isn't from portal? No? No, no, synthetic aperture. Yeah, 0:20:56.720 --> 0:20:59.840 they're like synthetic aperture telescopes. It's a. It's a it's 0:20:59.840 --> 0:21:02.400 a yeah. Yeah, it's totally think it's a really cool thing. Uh. 0:21:02.560 --> 0:21:05.960 Synthetic aperture means that the radar equipment is on a 0:21:06.040 --> 0:21:11.200 moving vehicle, which, to simplify the science ridiculously like almost criminally, 0:21:11.480 --> 0:21:14.440 means that the aperture of the antenna can be as 0:21:14.520 --> 0:21:17.679 long as the vehicle's flight path. And let me let 0:21:17.720 --> 0:21:20.240 me explain that a little bit, because it makes absolutely 0:21:20.240 --> 0:21:22.560 no sense the way I just said it. Okay, picture 0:21:22.600 --> 0:21:27.680 a dish antenna, right, It's aperture is its diameter. Okay. Uh, 0:21:27.800 --> 0:21:30.159 the greater the size of the dish, and that's the 0:21:30.160 --> 0:21:32.399 greater the size of the aperture, the more data the 0:21:32.440 --> 0:21:35.840 dish can take in. Uh, Thus the finer the resolution 0:21:36.160 --> 0:21:38.399 of the final image that it creates. It's similar to 0:21:38.440 --> 0:21:40.440 how film cameras work. You know, like if you've got 0:21:40.880 --> 0:21:44.639 a wider lens aperture, more light can come in and 0:21:44.680 --> 0:21:47.280 you can take a higher resolution photograph. Yeah, this is 0:21:47.400 --> 0:21:51.760 one reason we can't say, resolve images of things that 0:21:51.840 --> 0:21:54.919 are really, really really far away. We just can't build 0:21:55.000 --> 0:21:58.479 telescopes with an aperture wide enough. Right. If you if 0:21:58.520 --> 0:22:01.560 you could imagine like in you know, infinitely large aperture, 0:22:01.640 --> 0:22:06.159 you could technically probably resolve almost anything out there. But 0:22:06.240 --> 0:22:08.840 this is totally like the yes, now zoom in. No, 0:22:09.119 --> 0:22:13.040 it doesn't always work like that. Zoom and enhanced zoom right, 0:22:13.119 --> 0:22:15.840 zoom and enhanced. Yeah, yeah, we usually zoom in. But 0:22:16.520 --> 0:22:18.840 it seems like it'd be impossible to build something that 0:22:18.920 --> 0:22:22.800 had a physical aperture that big, right. And you know, 0:22:22.920 --> 0:22:24.879 if you put an antenna on a vehicle like an 0:22:24.880 --> 0:22:27.920 airplane or satellite, it means that you're limiting the physical 0:22:27.960 --> 0:22:30.480 size of the antenna to what that craft can carry. 0:22:31.160 --> 0:22:33.760