During my IFR training I "discovered" that Canada has a number of airports that are below the RADAR. For example; a vectored approach to CYGR is not available to non pressurized aircraft, as they are not able to fly high enough to appear on the screens at Moncton Centre. Only non precision approaches are allowed. Even the pressurized aircraft generally rely on the old stopwatch because a vectored approach would be longer than the entire flight. This is surprisingly common for advisory and uncontrolled airspace. Sometimes, a pilot in these locations even has to consider that communication will be restricted, as the VHF disappears below the horizon.
Yes they can indeed. Some years ago a privately owned Cessna was involved in an airprox incident and collided mid air with an RAF aircraft between Doncaster and Gainsborough. The Cessna was carrying a substantial amount of cocaine and came down in local fields. I’ve never seen so many police descend upon an area. No idea what became of the other aircraft.
RADAR is line of sight. When you’re talking about flying below the RADAR you can only do that when you’re out of the RADAR’s line of sight and the primary way that happens is when you’re below the horizon relative to the RADAR antenna. So if you can keep below the curvature of the earth, or in the shadows created by things like hills and mountains, then you can fly below the RADAR. I’m not sure how the Flat Earthers deal with the curvature of the Earth problem though. 🤔 In their model the RADAR waves magically bend up I guess.
@@abikeanditsboy3449 You're ignoring the fact that modern radars also include a lot of filters and such that deliberately filter out both low and relatively slow moving returns.
@@poiu477 - I'm not ignoring anything. I simply didn't comment on those things but because you think they’re important I’ll add them. An airport surveillance RADAR (ASR), the primary RADAR, cannot discriminate altitude. #1 From positioning and reference pulses from the antenna we know the azimuth where the antenna is pointed at any given time. #2 The time between the transmit pulse and the return echo tells us the range to the target. #3 Because of the way the beam is formed all altitudes are “seen” simultaneously. The ASR doesn’t discriminate in altitude because it doesn’t scan in altitude, it only scans in azimuth. You can have a target at 2500 feet and one at 25000 feet and all the RADAR knows is the linear distance from the target to the antenna. This is why there’s a second antenna on top of the ASR antenna. The second antenna is for the synthetic RADAR which returns information such as A/C codes and altitudes which can be displayed on top of the primary return. I this way you now have a 3D picture of what’s happening out there. In general, all returns are processed and displayed on the controller’s scopes. That works great except close in where the strength of the returns from the ground clutter is greater than the strength of the returns from the aircraft. This results in a white out at the center of the controller’s scope and they can’t see anything. The plus with normal RADAR is, regardless of the target’s speed, it will be displayed on the controller’s scope. A barn on a hill 30 miles out will be displayed even if the barn is moving very slowly. To overcome the close in ground clutter and see the moving targets the RADAR has a gated MTI (moving target indicator) mode. MTI mode eliminates the fixed returns from the moving returns and passes on data from the moving returns only. Because of how it’s determined a target is moving targets moving below a certain speed are ignored. A car moving at 30 mph isn’t an airplane and isn’t landing so we don’t care. A car moving at 60 mph will be seen and since we know where the roads are we can be fairly certain it’s a car on the road and we still don’t care. The point of MTI is to eliminate fixed targets and display moving ones. The filters you refer to may not be terrible effective. STC simply attenuates the gain of the LNAs which doesn’t really help when the strength of the return from ground clutter is greater than that of the A/C of interest. You just lower the overall gain of everything which doesn’t help the A/C stand out better. For a land based system STC isn’t super effective. MTI addresses this problem. FTC is more effective. On long returns, such as a rain storm, FTC displays the leading edge of the long return and blanks out the rest leaving us to see the A/C target in the storm. A long return like a rain storm has a lot of low frequency content which is why you have this large block of video on the display. FTC is a fast time constant which filters low frequency content and passes higher frequency content allowing us to see the A/C in the storm. Think FFT. The leading edge of the signal you’re doing an FFT on is where the high frequency content is. If you delete the low frequency content of the FFT and only pass along the high frequency components all you see is the leading edge. There are other things like blind speed on a RADAR where a target flying at a particular speed isn’t seen even though it’s moving. Those are well known and there’s methods to overcome that so it’s not all that important. Now for the Cesssna. There are a couple possibilities. If the controllers aren’t using the primary radar and only using the secondary radar, and the Cessna has its transponder turned off, then the Cessna will not be seen by the RADAR and it’s essentially not there. Computer systems won’t see it and you won’t get any collision alerts. That’s a possibility. The other possibility is the two planes were low level and depending on where the RADAR for that airspace is located; the planes could have been below the horizon and not seen either. Hence, what’s known as flying below the RADAR. As I said in my other comment RADAR is line of sight and the ASR can’t see below the horizon so the curvature of the earth will mask a low level airplane. Normally, before an ASR is accepted it’s flight checked and all the nulls and holes and blind spots are plotted and mapped. Did I ignore something else that should be include?
as an air traffic controller in the mountain west of the US, there are lots of areas where we don’t see primary targets. radar is line of sight based and well… mountains block line of sight.
Does you airport have the ability and financial means to install an additional electromagnetic wave transmitter and receiver for radar and transponder purposes?
As a fellow pilot, lot's of guy's in the Bahamas have told me stories about avoiding radar ...since the statute of limitations had expired on their "import/export" runs of "high value cargo" :)
Awesome as usual, Joe. However, I spent many years in the USAF as a radar tech, and I'd like to expand upon your description of radar. All of the radars with which I was familiar are not omnidirectional but instead use a rotating vertical wedge-shaped beam that might rotate at ~6 RPM for long-range radar and higher RPMs for shorter-range radar. So the radar pulse goes out, hits an object, and the return comes back. By measuring the length of time between pulse and return, the range to the target can be determined. By measuring the direction the antenna is pointing, bearing to the target is also determined. This is all old-fashioned radar, giving what we called "skin-paints", and like you said does not provide altitude info. More modern 3D radar such as used by the military or weather stations uses a pencil-shaped beam that scans vertically very fast, while still rotating in azimuth. By timing the returns exactly, the angle up or down to the target, the azimuth to the target, and the range to the target can all be computed with remarkable accuracy. (Hope this isn't too far into the weeds for folks...) EDIT: Some air traffic control radars like the ARSR-4 have the ability to provide limited elevation information by using "stacked beams" and measuring relative target strength in each beam, but it's not as precise as true 3-D radar. But it all makes deliberate hiding from radar more problematic. And like @doctorscoot said below, you can also get direct measurement of target speed by comparing doppler shift of the returned pulses. It's actually pretty amazing tech.
Lots of limitations anyway, windmills also create Doppler Shift, so de-cluttering creates a limitation , and secondary radar has severe problem of over interrogation due to the same frequencies being used by mode S, TCAS, and ADSB. On a far distance the altitude resolution highly depends on beam width of the 3D radar antenne, and so on. Appreciated your very correct reaction.
I'm 16 and aspiring to become a pilot like u,u r my inspiration,i hope i will meet you someday in future,stay safe and take care cap and don't forget A GOOD PILOT IS ALWAYS LEARNING
Nice part about the transponder there. I'm still having a bit of trouble understanding it. Wanna say that you're a big inspiration to me, and stumbling upon one of your videos a while back pretty got me into aviation. Currently 16 and enrolled in flight school.. Kinda reminds me of my grandfather, he was a private pilot but he also was an electrical engineer and worked on radars. Love you dude, keep up the good work and stay safe! :)
The ground radar sends a call "Anyone out there?" and all aircraft transponders who receive that call answer with their credentials. Then the ground radar can send a spesific call, meant to that single one aircraft which responds with more details. Repeat step two and your radar system tracks all aircrafts in it's area.
Thnx for your christal clear lesson. "A good pilot is always learning"... You too? Two pronunciation tips: - bearing is to sound like (Tu-95) Bear-ring - Altitude should be (Big) Al-titude (Ein enthousiaster Abonnent in Holland 😉)
I enjoy your videos Joe. As a former VFR pilot it is fun to hear about IFR and the vast numbers of other matters you cover. And yes, I have subscribed!
In the early 1980s, at the tail end of the cold war, NORAD switched it's mission (or better I should say expanded it's mission) to include drug smuggling interdiction. We started using radar lofted up by dirigible (balloon). That gave us radar coverage down pretty much to the water surface since the radar is not looking UP but rather DOWN on the scene.
Patrolling pipelines that plowed right across and closely beside major airports in Class B airspace, I found altitude under the layers of the upside down wedding cake to be of great advantage to VFR traffic. I made use of the 200' AGL waiver to work traffic free except crossing runways including parallel runways. Approach naturally wants traffic up where they can see it, but they really want nothing to do with pipeline patrol. I simply reported to tower five miles out and was given excellent service all the way through. 360 degree turns were commonly required, but the area was traffic free. Airline pilots with TCAS concerns were often advised, "He's 50' off the trees. He's not traffic." It was like a warm blanket. While you don't have the waiver for complete traffic avoidance, you might find the airspace under layers to be an advantage when Approach is too busy to handle you VFR because you are not going to the primary airport.
Captain Joe call it Primary and secondary radar, but the military call it search and targeting radar. The search radar is for general surveillance and the targeting radar will paint a target with much more precision to launch missiles. There is another type they call look down and shoot down radar, It can be carried by a DC3 or even an airship for all I care., but you got to be at the right place and right time. They will be better at picking up fast moving objects in the ground clutter, and in places like the US southern coast there are no clutter at the Gulf and you stand out like a sore thumb with seamless wall to wall radar coverage. That is why drug running by stolen airplanes are no longer done.
A civil radar / navigation radar you can’t get altitude but a military beam array radar e.g. Aegis absolutely can (also relative speed to the transmitter by way of Doppler shift)
@@Eluderatnight yes, and something with a steerable narrow beam like aegis uses simple trig at the core (lol) to figure out a distance of ‘r’ to the contact at some bearing ‘b’ and elevation ‘θ’ (usually in degrees, but using radians for the maths will make it easier) this gives you a precise point in the 3d hemisphere* around the ship or aviation asset. (*maybe another spherical section or even a cone). I don’t think Raytheon will sell you one though 🤷♀️
"A good pilot is always learning" should be like Captain Joe's signature or something Reminds me how I'd watch Captain Joe's videos overnight when I first followed him, back in 2018; there was too many of them and couldn't get enough ☺
Me too, since my 1st year in university in late 2018, started with ILS and ATIS videos and now I watched all of Captain Joe's videos and still looking for updates
Worth noting that Army (and Navy) has onboard flying RADAR, AWACS, such as E-3 or E-2 or A-50, KJ-2000 on the other side. Those provide better detection as they fly in the altitude and are less affected by Earth's curvature or terrain.
Excellent video on radar! Would love to see you do a video about Raytheon’s ADSR (Airport Digital Surveillance Radar) series that is used almost world wide. Also would like to see a video on digital ground radar that’s only been around since last decade. Thanks!
You can fly under the radar if you are close to the ground or other surface. Military aircraft do this all the time. Of course the other option is to fly below the terrain, in a valley or something similar.
It works similar to light since light waves are also electromagnetic waves. I studied optics in college physics and we really go deep into how electromagnetic waves work starting from the Maxwell's equations.
Sure. A while back, a lightplane ran into a bridge overpass while following FWY 5 northbound. The overpass was about 30 feet over the superslab, and the aircraft contained contraband. It was a night flight, obviously.
Hey Joe hope ur well bud. Great video we was howling in the hanger earlier at ur boeing engine noise start short video. Can't believe they use that noise 😂😂
Very good and accurate explanation! RADAR creates bubbles of coverage in the atmosphere, converging in the altitudes of interest. What we're doing is flying in the gaps between bubbles and in shadows cast by terrain and obstacles at the low altitudes. For defense, large countries like the Russia and USA have very well covered borders with downward-looking RADAR, to ide tify low-flying threats, eliminating the ability to "fly below the RADAR". Once well inside national borders, these gaps may appear, particularly in rural areas. Flying above RADAR coverage is difficult and very costly. (There are some unimportant nuances like beam bending over the horizon due to gravity and beam convergence behind a smaller obstacles, but these are largely negligible for the topic.)
In the mid-90s I had the pleasure of being contracted to fly a cessna 310 against the aerostat balloons on cudjoe key and aboard boats out of key west. They had installed new radars and were tuning them. When they were done they could see that 310 anywhere, everywhere, and at any time.
My expectation would have been that in earlier days there might have been more "deadspots" in radar coverage. Now with more sophisticated technology and probably more stations providing coverage it would be pretty difficult to find uncovered areas except in maybe the most remote locations. Would that assumption be accurate or was it truly never a thing to be able to avoid radar detection?
The system depends on pilots configuring their traansponders correctly. A few years ago I got chewed out by the local tower for busting circuit altitude. My altimeter was correct but the transponder was sending incorrect data.
I was waiting for an American Made reference. 😎 I've practiced low-level flight. Not to evade The Authorities, but if I should ever need to divert under a low ceiling. Can't say I like it.
@@flywithcaptainjoe That would be great. Such a great aviation movie. And you could explain us if it is a good idea to put flaps out to fly longer as they do in the movie for example? Does flying slower with reduced engine power and flaps compensate for the drag ? I would love to hear your take on this and somany things about this movie !
@@valentinloew If you're flying slowly you are closer to your stall speed. Flaps reduce your stall speed and make your flying safer. At 100 feet off the water you don't want to stall...
@@marsgal42 true but that's not my point. It's not about stalling it's about saving fuel. in the movie they try to fly for as long as possible, they put the flaps out and most likely reduce engine power to fly slow and save fuel, so the DEA jet has to leave because they go BINGO. But the backside is that flaps increase drag, and thus make you spend more fuel. You can still fly slowly without flaps though, it's indeed more dangerous, but possible. I'm just curious wich is best. That's why that would be cool to have captain joe's opinion :)
@@valentinloew The flaps reference is curiously specific and doesn't apply to anything I've ever flown. In the movie only the Aerostar has its flaps out, the other planes do not. Flying for maximum endurance is something all pilots learn early in flight training. How long can your plane stay in the air? Mine is good for about 8 hours.
I live up in the mountains in west Virginia. About a month ago at around 10:00 pm I heard the low rumble of an engine out in front of my house. I thought that a Big Semi was cutting through the neighborhood .I look out and didnt see anything .Then out of nowhere came about 5 Massive Military Planes flying tree top level over my house .The were following each other in a single file line ..Was Wild to see
Yes, but how much more are you willing to pay for a ticket? And, technically, the AWACS always flies below the RADAR, unless it channels its inner 'Tom Cruise / Maverick' and goes inverted.......... ;-)
Having spent a few years flying night mail across Montana I can assure you that in mountainous areas it is more difficult to obtain radar coverage than to avoid it! In the days before GPS it was pretty basic non-radar flying and approaches.
I'd say yes they can. I know due to hills microlights could fly below the radar if they were below 400 metres around me but they weren't meant to. Other radars around the country can pick up trucks. I was wondering how FlightAware worked. Must look out for your video.
I have one minor clarification on what you said. The RADAR isn't technically omni-directional. It’s very much unidirectional and has a very narrow beam width for horizontal resolution between aircraft. The other reason for the narrow beam is the wider the beam is the more degrees of arc an aircraft will show up on the controller’s scope. No one wants to see a plane with a 170 foot wingspan taking up 15 degrees of arc and looking like its 20 miles wide. Nope, you want that beam to be pretty narrow especially since you’re looking at primary targets out to about 60NMI. The other thing is the pulse width is very short, like under a microsecond, so you can resolve distance between aircraft. What makes the RADAR “omni-directional” is the simple fact that the antenna spins.
Maybe an idea for a video: I am curious Can a passenger really go to the door and open it at 1000 feet, Like we heard about in Korea this week? In terms of policy, who's guarding the doors, Air pressure/technical difficulty?
Small point of critique: RADAR energy will touch the plane, even if its behind a mountain, horizon or other obstacles. The reflected energy does reach the receiver of the RADAR but at that point the phase-relation between what that transmitter send and what the receiver received is no longer coherent. Therefore the RADAR doesn't recognize its own signal any-more and will filter it out as being 'noise'. Same as shouting "ECHO!" into a canyon and hearing some sound coming back but being unable to recognize the word 'echo' (or even that it has two syllables).
They used to say that the C411 - C421 had nice rear cabin access doors. Take out the seats, fly into a canyon, you don't even have to throw the gear down, just a slow pass, empty the plane, and fly the interstate the hell out of there until you get back on ATC and put down at some Hooverville in the desert. That's just what they used to say. I have no personal knowledge thereof.
Good video, exited for the video coming about ADSB cause it’s a really interesting project for ATC especially in the US and over the oceanic regions :)
@@flywithcaptainjoe could you talk about the lightning aspect with it too… had 2 antennas on the side of my house feeding to fr24 and flight aware and they both got struck and weren’t grounded
During 9/11, the ATC communications are commonly saying AA11 has turned off their transponder, and they have him only on primary. Other ATC people in the communication loop are astounded and confused by this. They assume the aircraft is still on the designated FL because they don't have any other information about the altitude other than what other aircraft report if they happen to be close. When you hear those communications, at least back in that era, you can tell ATC are trained only in what good pilots would and should be doing. They can't get their head out of the box that someone could be doing something bad and that's why the transponder is off. It's not hard to imagine drug runners back in the day were able to outfox the law, unless the law used dedicated airborne resources to track the drug runner.
This is very well explained (Not a pilot but a RF Guy). "Flying Under The Radar" in battlefield for drug smuggling operation I think would be quite different/difficult. Down looking Radars from above would make un-detected low flying very hard. AWAC or better yet a hand full of these small NEO satellites "Space X" would be able to catch a lot of anything. But I do like the explanation.
Both primary, secondary/ADS-B have a lot of low altitude holes in their coverage. You need to know where the ground systems are located and what the terrain is. A composite aircraft is preferred to address primary radar and a direct pilot means of removing power from your transponder for all the other stuff.
I really prefer these long (normal) form videos! Please keep it up! Also i would like to see a follow-up video explaining all the weirdness of (primary) radar systems, like reflections, ghosting an the like, and how controllers know which is actually the real target when there is no secondary radar information! Maybe you could also mention/explain how the (US-?) military actually can detect stealth aircraft by interconnecting multiple different ground stations.
Commercial flights within the EU use the Mode S a lot. They all get the squawk 1000 in that case IIRC. But that's not the case with the flights e g. between the EU and UK
Interesting that it is now called “secondary radar” as we called it “Identification Friend or Foe” when I worked on military radar. And it really isn’t radar at all as it relies on responses from the aircraft’s transponder.
Grand Theft Auto V has a mission where Trevor has to fly low in order to avoid being detected in a no-fly zone and you can also fly under bridges with a small two-engine plane.
l'm watching some vídeos of his beginnings, and l have to say they are really Great. Now l can understand some comments. l see that you have taken t'hem Up again . And continues in the same line of infirmative and interesting . l loved the video .
He Joe. I just wanted to know why the technology in commercial aircraft seems so dated. I see the instruments that modern aircraft have and it just seems old
Wait a minute... I can still see 3 stripes on the uniform. In an older video in the stripes of pilot uniform you said that you were nearing promotion to captain. What happened?
I know that this is a channel about aviation but I was watching your video about birds flying into planes and saw that you had the Falcon from Star Wars on your wall. I would like a fun video about aviation in the Sci-Fi genre and which vehicles would you like to fly in Sci-Fi. I hope you consider this, please! Thank you! I love your videos I have learned a whole lot from your videos about aviation!!
@CaptainJoe... I don't have a cell phone to get a text nor do I know how to DM from You Tube. So what does this comment mean. And what did I win if anything? Thank you!
Very informative videos! Thank you. I recently moved my house and its close to flightpath, its a tall rise and I can see almost all takeoffs and landings. I have noticed that while taking off the vertical height between my floor and flight is quite high, but while landing, its almost as close to my balcony. Is there any particular reason for that?
For sure Radar DOES NOT use omnidirectionnal antennas as already commented by William Harvey. Best regards, some Electrical Engineer and Radio Amateur from Hamburg, Germany.
"Drug Smuggling" Tips by CAPTAIN JOE
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And yet it can not be classified as a bait title 😂
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Yea, your all set now,huh?
in the next chapter, how to paint your plane in camo.
During my IFR training I "discovered" that Canada has a number of airports that are below the RADAR. For example; a vectored approach to CYGR is not available to non pressurized aircraft, as they are not able to fly high enough to appear on the screens at Moncton Centre. Only non precision approaches are allowed. Even the pressurized aircraft generally rely on the old stopwatch because a vectored approach would be longer than the entire flight. This is surprisingly common for advisory and uncontrolled airspace. Sometimes, a pilot in these locations even has to consider that communication will be restricted, as the VHF disappears below the horizon.
Thanks for the great info!
@@flywithcaptainjoehello
Captain Joe, can planes fly low altitude with autopilot on
Yes they can indeed. Some years ago a privately owned Cessna was involved in an airprox incident and collided mid air with an RAF aircraft between Doncaster and Gainsborough. The Cessna was carrying a substantial amount of cocaine and came down in local fields. I’ve never seen so many police descend upon an area. No idea what became of the other aircraft.
RADAR is line of sight. When you’re talking about flying below the RADAR you can only do that when you’re out of the RADAR’s line of sight and the primary way that happens is when you’re below the horizon relative to the RADAR antenna. So if you can keep below the curvature of the earth, or in the shadows created by things like hills and mountains, then you can fly below the RADAR. I’m not sure how the Flat Earthers deal with the curvature of the Earth problem though. 🤔 In their model the RADAR waves magically bend up I guess.
@@abikeanditsboy3449 I suppose, in the flat earth scenario, you would probably have to fly beyond the ice wall at the edge of the earth. 🤷🏿♂️
@@abikeanditsboy3449 You're ignoring the fact that modern radars also include a lot of filters and such that deliberately filter out both low and relatively slow moving returns.
@@poiu477 - I'm not ignoring anything. I simply didn't comment on those things but because you think they’re important I’ll add them.
An airport surveillance RADAR (ASR), the primary RADAR, cannot discriminate altitude. #1 From positioning and reference pulses from the antenna we know the azimuth where the antenna is pointed at any given time. #2 The time between the transmit pulse and the return echo tells us the range to the target. #3 Because of the way the beam is formed all altitudes are “seen” simultaneously. The ASR doesn’t discriminate in altitude because it doesn’t scan in altitude, it only scans in azimuth. You can have a target at 2500 feet and one at 25000 feet and all the RADAR knows is the linear distance from the target to the antenna. This is why there’s a second antenna on top of the ASR antenna. The second antenna is for the synthetic RADAR which returns information such as A/C codes and altitudes which can be displayed on top of the primary return. I this way you now have a 3D picture of what’s happening out there.
In general, all returns are processed and displayed on the controller’s scopes. That works great except close in where the strength of the returns from the ground clutter is greater than the strength of the returns from the aircraft. This results in a white out at the center of the controller’s scope and they can’t see anything. The plus with normal RADAR is, regardless of the target’s speed, it will be displayed on the controller’s scope. A barn on a hill 30 miles out will be displayed even if the barn is moving very slowly.
To overcome the close in ground clutter and see the moving targets the RADAR has a gated MTI (moving target indicator) mode. MTI mode eliminates the fixed returns from the moving returns and passes on data from the moving returns only. Because of how it’s determined a target is moving targets moving below a certain speed are ignored. A car moving at 30 mph isn’t an airplane and isn’t landing so we don’t care. A car moving at 60 mph will be seen and since we know where the roads are we can be fairly certain it’s a car on the road and we still don’t care. The point of MTI is to eliminate fixed targets and display moving ones.
The filters you refer to may not be terrible effective. STC simply attenuates the gain of the LNAs which doesn’t really help when the strength of the return from ground clutter is greater than that of the A/C of interest. You just lower the overall gain of everything which doesn’t help the A/C stand out better. For a land based system STC isn’t super effective. MTI addresses this problem.
FTC is more effective. On long returns, such as a rain storm, FTC displays the leading edge of the long return and blanks out the rest leaving us to see the A/C target in the storm. A long return like a rain storm has a lot of low frequency content which is why you have this large block of video on the display. FTC is a fast time constant which filters low frequency content and passes higher frequency content allowing us to see the A/C in the storm. Think FFT. The leading edge of the signal you’re doing an FFT on is where the high frequency content is. If you delete the low frequency content of the FFT and only pass along the high frequency components all you see is the leading edge.
There are other things like blind speed on a RADAR where a target flying at a particular speed isn’t seen even though it’s moving. Those are well known and there’s methods to overcome that so it’s not all that important.
Now for the Cesssna. There are a couple possibilities. If the controllers aren’t using the primary radar and only using the secondary radar, and the Cessna has its transponder turned off, then the Cessna will not be seen by the RADAR and it’s essentially not there. Computer systems won’t see it and you won’t get any collision alerts. That’s a possibility. The other possibility is the two planes were low level and depending on where the RADAR for that airspace is located; the planes could have been below the horizon and not seen either. Hence, what’s known as flying below the RADAR. As I said in my other comment RADAR is line of sight and the ASR can’t see below the horizon so the curvature of the earth will mask a low level airplane.
Normally, before an ASR is accepted it’s flight checked and all the nulls and holes and blind spots are plotted and mapped.
Did I ignore something else that should be include?
Terrestrial radar has many limits. AIRBORN radar (AWACS, JSTARS) have a much better view as the Eye in the Sky.
as an air traffic controller in the mountain west of the US, there are lots of areas where we don’t see primary targets. radar is line of sight based and well… mountains block line of sight.
Which, I'm guessing, also explains the very small areas where class G airspace still goes to 14,500 MSL.
Thanks for the info!
Does you airport have the ability and financial means to install an additional electromagnetic wave transmitter and receiver for radar and transponder purposes?
@@flywithcaptainjoe 😂
@@hbarudi US Aviation infrastructure is underfunded af, prob not
As a fellow pilot, lot's of guy's in the Bahamas have told me stories about avoiding radar
...since the statute of limitations had expired on their "import/export" runs of "high value cargo" :)
Awesome as usual, Joe. However, I spent many years in the USAF as a radar tech, and I'd like to expand upon your description of radar. All of the radars with which I was familiar are not omnidirectional but instead use a rotating vertical wedge-shaped beam that might rotate at ~6 RPM for long-range radar and higher RPMs for shorter-range radar. So the radar pulse goes out, hits an object, and the return comes back. By measuring the length of time between pulse and return, the range to the target can be determined. By measuring the direction the antenna is pointing, bearing to the target is also determined. This is all old-fashioned radar, giving what we called "skin-paints", and like you said does not provide altitude info. More modern 3D radar such as used by the military or weather stations uses a pencil-shaped beam that scans vertically very fast, while still rotating in azimuth. By timing the returns exactly, the angle up or down to the target, the azimuth to the target, and the range to the target can all be computed with remarkable accuracy. (Hope this isn't too far into the weeds for folks...)
EDIT: Some air traffic control radars like the ARSR-4 have the ability to provide limited elevation information by using "stacked beams" and measuring relative target strength in each beam, but it's not as precise as true 3-D radar. But it all makes deliberate hiding from radar more problematic. And like @doctorscoot said below, you can also get direct measurement of target speed by comparing doppler shift of the returned pulses. It's actually pretty amazing tech.
Lots of limitations anyway, windmills also create Doppler Shift, so de-cluttering creates a limitation , and secondary radar has severe problem of over interrogation due to the same frequencies being used by mode S, TCAS, and ADSB. On a far distance the altitude resolution highly depends on beam width of the 3D radar antenne, and so on. Appreciated your very correct reaction.
I'm 16 and aspiring to become a pilot like u,u r my inspiration,i hope i will meet you someday in future,stay safe and take care cap and don't forget
A GOOD PILOT IS ALWAYS LEARNING
..suggest you approach a full-fledged REAL CAPTAIN.
it's been a long time ..no new video..
Miss seeing your newer episodes 👍
Any one who know if our captain os ok? No youtube post for 3 month?😢
Matthias Rust in a Cessna flew into Moscow and landed on the Red Place back in the 80's during Cold War below radar.
Nice part about the transponder there. I'm still having a bit of trouble understanding it. Wanna say that you're a big inspiration to me, and stumbling upon one of your videos a while back pretty got me into aviation. Currently 16 and enrolled in flight school.. Kinda reminds me of my grandfather, he was a private pilot but he also was an electrical engineer and worked on radars.
Love you dude, keep up the good work and stay safe! :)
Thanks buddy! Appreciate the kind words!
The ground radar sends a call "Anyone out there?" and all aircraft transponders who receive that call answer with their credentials. Then the ground radar can send a spesific call, meant to that single one aircraft which responds with more details.
Repeat step two and your radar system tracks all aircrafts in it's area.
@@flywithcaptainjoe Literally dying, my idol replied to me WHAAAAAAAAA
Thnx for your christal clear lesson.
"A good pilot is always learning"... You too?
Two pronunciation tips:
- bearing is to sound like (Tu-95) Bear-ring
- Altitude should be (Big) Al-titude
(Ein enthousiaster Abonnent in Holland 😉)
Copied :)
Has Captain Joe given up with more videos? 🤔
In the Florida Keys, they have a tethered balloon with radar or other sensors, I believe, to detect smugglers. Can't fly below that.
I enjoy your videos Joe. As a former VFR pilot it is fun to hear about IFR and the vast numbers of other matters you cover. And yes, I have subscribed!
Thanks Bibber!
In the early 1980s, at the tail end of the cold war, NORAD switched it's mission (or better I should say expanded it's mission) to include drug smuggling interdiction. We started using radar lofted up by dirigible (balloon). That gave us radar coverage down pretty much to the water surface since the radar is not looking UP but rather DOWN on the scene.
And this is still used today on the Aerostat system which we have around all of our borders.
Patrolling pipelines that plowed right across and closely beside major airports in Class B airspace, I found altitude under the layers of the upside down wedding cake to be of great advantage to VFR traffic. I made use of the 200' AGL waiver to work traffic free except crossing runways including parallel runways. Approach naturally wants traffic up where they can see it, but they really want nothing to do with pipeline patrol. I simply reported to tower five miles out and was given excellent service all the way through. 360 degree turns were commonly required, but the area was traffic free. Airline pilots with TCAS concerns were often advised, "He's 50' off the trees. He's not traffic." It was like a warm blanket. While you don't have the waiver for complete traffic avoidance, you might find the airspace under layers to be an advantage when Approach is too busy to handle you VFR because you are not going to the primary airport.
Captain Joe call it Primary and secondary radar, but the military call it search and targeting radar. The search radar is for general surveillance and the targeting radar will paint a target with much more precision to launch missiles. There is another type they call look down and shoot down radar, It can be carried by a DC3 or even an airship for all I care., but you got to be at the right place and right time. They will be better at picking up fast moving objects in the ground clutter, and in places like the US southern coast there are no clutter at the Gulf and you stand out like a sore thumb with seamless wall to wall radar coverage. That is why drug running by stolen airplanes are no longer done.
A civil radar / navigation radar you can’t get altitude but a military beam array radar e.g. Aegis absolutely can (also relative speed to the transmitter by way of Doppler shift)
Raymarine(teledyne) lets you look up or down but no altitude. Only showing a blob over there on weather mode or blob(boat) on the horizon for else.
@@Eluderatnight yes, and something with a steerable narrow beam like aegis uses simple trig at the core (lol) to figure out a distance of ‘r’ to the contact at some bearing ‘b’ and elevation ‘θ’ (usually in degrees, but using radians for the maths will make it easier) this gives you a precise point in the 3d hemisphere* around the ship or aviation asset. (*maybe another spherical section or even a cone). I don’t think Raytheon will sell you one though 🤷♀️
enjoying from Zimbabwe
Hey Captain Joe, that lovely lady in your book advert is beautiful across generations. She's like a modern Sophia Loren.
And the best part, she has no social media account :)
Would be nice to see new video of Captain Joe with Dutch Pilot Girl, last one was from 2019?
"A good pilot is always learning" should be like Captain Joe's signature or something
Reminds me how I'd watch Captain Joe's videos overnight when I first followed him, back in 2018; there was too many of them and couldn't get enough ☺
Happy to hear that Simon. More to come!
Me too, since my 1st year in university in late 2018, started with ILS and ATIS videos and now I watched all of Captain Joe's videos and still looking for updates
He sells a T-shirt with that in the Captain Joe store if you're so inclined... 😀
Worth noting that Army (and Navy) has onboard flying RADAR, AWACS, such as E-3 or E-2 or A-50, KJ-2000 on the other side. Those provide better detection as they fly in the altitude and are less affected by Earth's curvature or terrain.
Good point, yes!
7:44 Oh Joe! I was just planning such a trip in my little Cesna to Cuba to well.... y'know do a little "shopping" but that spoilt it
Haha, funny comment :)
I'm so happy that you are so confident in yourself with that book! dream on Joe and NEVER quit making videos because we enjoy them so much!!
Excellent video on radar! Would love to see you do a video about Raytheon’s ADSR (Airport Digital Surveillance Radar) series that is used almost world wide. Also would like to see a video on digital ground radar that’s only been around since last decade. Thanks!
Roger, copied!
You can fly under the radar if you are close to the ground or other surface. Military aircraft do this all the time. Of course the other option is to fly below the terrain, in a valley or something similar.
Well that's a title worth remembering!
Haha :)
It works similar to light since light waves are also electromagnetic waves. I studied optics in college physics and we really go deep into how electromagnetic waves work starting from the Maxwell's equations.
Sure. A while back, a lightplane ran into a bridge overpass while following FWY 5 northbound. The overpass was about 30 feet over the superslab, and the aircraft contained contraband. It was a night flight, obviously.
When sh... hits a bridge !
Legend has it that fishermen reported getting high after eating fish from that river 😜
Thanks! I'll keep in mind for my next drug run😊
I love the engineering aspect of your explanations
Hey Joe hope ur well bud. Great video we was howling in the hanger earlier at ur boeing engine noise start short video.
Can't believe they use that noise 😂😂
Very good and accurate explanation!
RADAR creates bubbles of coverage in the atmosphere, converging in the altitudes of interest. What we're doing is flying in the gaps between bubbles and in shadows cast by terrain and obstacles at the low altitudes. For defense, large countries like the Russia and USA have very well covered borders with downward-looking RADAR, to ide tify low-flying threats, eliminating the ability to "fly below the RADAR". Once well inside national borders, these gaps may appear, particularly in rural areas. Flying above RADAR coverage is difficult and very costly.
(There are some unimportant nuances like beam bending over the horizon due to gravity and beam convergence behind a smaller obstacles, but these are largely negligible for the topic.)
Excellent video. Stuff like this just makes you want to become a pilot just to use it.
@CaptainJoe... Not sure I get your response.
Stay safe cap
I am always happy when our captain Joe post a video!
In the mid-90s I had the pleasure of being contracted to fly a cessna 310 against the aerostat balloons on cudjoe key and aboard boats out of key west. They had installed new radars and were tuning them. When they were done they could see that 310 anywhere, everywhere, and at any time.
Keep going I love you
Thank you, will keep these in mine
My expectation would have been that in earlier days there might have been more "deadspots" in radar coverage. Now with more sophisticated technology and probably more stations providing coverage it would be pretty difficult to find uncovered areas except in maybe the most remote locations. Would that assumption be accurate or was it truly never a thing to be able to avoid radar detection?
If you wanna have that experience you'll find that large parts of e.g. Africa are still without radar coverage to this day
What if an aircrafts transponder sends false data? That would mess up things a lot, right?
The system depends on pilots configuring their traansponders correctly.
A few years ago I got chewed out by the local tower for busting circuit altitude. My altimeter was correct but the transponder was sending incorrect data.
lol that title will get you on an FBI list Joe 🤣🤣🤣🤣
That would be an interesting interview ;)
Incredible, thank you so much, nice to return on TH-cam long shots
They were never gone :)
I was waiting for an American Made reference. 😎
I've practiced low-level flight. Not to evade The Authorities, but if I should ever need to divert under a low ceiling. Can't say I like it.
That movie needs an explanation video😉
@@flywithcaptainjoe That would be great. Such a great aviation movie. And you could explain us if it is a good idea to put flaps out to fly longer as they do in the movie for example? Does flying slower with reduced engine power and flaps compensate for the drag ? I would love to hear your take on this and somany things about this movie !
@@valentinloew If you're flying slowly you are closer to your stall speed. Flaps reduce your stall speed and make your flying safer. At 100 feet off the water you don't want to stall...
@@marsgal42 true but that's not my point. It's not about stalling it's about saving fuel. in the movie they try to fly for as long as possible, they put the flaps out and most likely reduce engine power to fly slow and save fuel, so the DEA jet has to leave because they go BINGO. But the backside is that flaps increase drag, and thus make you spend more fuel. You can still fly slowly without flaps though, it's indeed more dangerous, but possible. I'm just curious wich is best. That's why that would be cool to have captain joe's opinion :)
@@valentinloew The flaps reference is curiously specific and doesn't apply to anything I've ever flown. In the movie only the Aerostar has its flaps out, the other planes do not. Flying for maximum endurance is something all pilots learn early in flight training. How long can your plane stay in the air? Mine is good for about 8 hours.
6:50 in addition to modes A, C, AND S, there is also modes 1-5 although they are not as commonly used by civilian aviation.
wonderful information's
I live up in the mountains in west Virginia. About a month ago at around 10:00 pm I heard the low rumble of an engine out in front of my house. I thought that a Big Semi was cutting through the neighborhood .I look out and didnt see anything .Then out of nowhere came about 5 Massive Military Planes flying tree top level over my house .The were following each other in a single file line ..Was Wild to see
Exciting!
Somebody just watched American Made
- 'Drug smuggling tips.'
Great and informative video that you have shared with us that watch your channel. This was so interesting.
Glad you enjoyed it
@@flywithcaptainjoe absolutely sir, thanks for taking the time to make these wonderful videos.
Flying below the radar was the reason for AWACS. I wonder if a drone based awacs system could be used for civilian aviation radar purposes?
Yes, but how much more are you willing to pay for a ticket?
And, technically, the AWACS always flies below the RADAR, unless it channels its inner 'Tom Cruise / Maverick' and goes inverted.......... ;-)
Having spent a few years flying night mail across Montana I can assure you that in mountainous areas it is more difficult to obtain radar coverage than to avoid it! In the days before GPS it was pretty basic non-radar flying and approaches.
I love the fact that the thumbnail contained an image of an Aerostar. How appropriate!
Hello joe! I just got your book in the mail and can’t wait to read it!
Awesome vid as always 👍
Thanks buddy!!!
I'd say yes they can. I know due to hills microlights could fly below the radar if they were below 400 metres around me but they weren't meant to. Other radars around the country can pick up trucks. I was wondering how FlightAware worked. Must look out for your video.
I have one minor clarification on what you said. The RADAR isn't technically omni-directional. It’s very much unidirectional and has a very narrow beam width for horizontal resolution between aircraft. The other reason for the narrow beam is the wider the beam is the more degrees of arc an aircraft will show up on the controller’s scope. No one wants to see a plane with a 170 foot wingspan taking up 15 degrees of arc and looking like its 20 miles wide. Nope, you want that beam to be pretty narrow especially since you’re looking at primary targets out to about 60NMI. The other thing is the pulse width is very short, like under a microsecond, so you can resolve distance between aircraft. What makes the RADAR “omni-directional” is the simple fact that the antenna spins.
FAA... OPEN UP! lmao
Very informative video Sir
Excellent video from Captain Joe, very good and easy to understand explanation about radar and airplanes. Thanks and good job Captain Joe ✈️🔥👍👍
My pleasure, and thank you!
Hi, what about new videos or shorts ? Thanks !!!!
Maybe an idea for a video: I am curious Can a passenger really go to the door and open it at 1000 feet, Like we heard about in Korea this week? In terms of policy, who's guarding the doors, Air pressure/technical difficulty?
Thanks Cap, will use this to improve my flight paths from Cartagena.
Small point of critique:
RADAR energy will touch the plane, even if its behind a mountain, horizon or other obstacles. The reflected energy does reach the receiver of the RADAR but at that point the phase-relation between what that transmitter send and what the receiver received is no longer coherent. Therefore the RADAR doesn't recognize its own signal any-more and will filter it out as being 'noise'.
Same as shouting "ECHO!" into a canyon and hearing some sound coming back but being unable to recognize the word 'echo' (or even that it has two syllables).
That's a weird conclusion saying that primary radar can still catch you, considering that earlier you said flying below the radar is possible...
Hey Captain Joe, quastion. Who decides the plane altitudes and how?
Usually the altitude is filed with ATC. But one can ask for a lower/higher level, or the ATC can assign a lower or ask if you can go higher.
You make everything so clear, Joe. Thank you so much for your great videos! I enjoy watching every single one of them.
They used to say that the C411 - C421 had nice rear cabin access doors. Take out the seats, fly into a canyon, you don't even have to throw the gear down, just a slow pass, empty the plane, and fly the interstate the hell out of there until you get back on ATC and put down at some Hooverville in the desert. That's just what they used to say. I have no personal knowledge thereof.
I've had antenna propagation and digital communication subject in engineering this video did gave me nostalgia
Good video, exited for the video coming about ADSB cause it’s a really interesting project for ATC especially in the US and over the oceanic regions :)
The ADSB Video is coming soon!
@@flywithcaptainjoe could you talk about the lightning aspect with it too… had 2 antennas on the side of my house feeding to fr24 and flight aware and they both got struck and weren’t grounded
Greatly explained ! Thanks ;)
Intro song is ehrling-lounge
The last time I was this early, I was called a gate louse. So happy you’re back here, Joe!
Thanks Lara! Appreciate it!!
During 9/11, the ATC communications are commonly saying AA11 has turned off their transponder, and they have him only on primary. Other ATC people in the communication loop are astounded and confused by this. They assume the aircraft is still on the designated FL because they don't have any other information about the altitude other than what other aircraft report if they happen to be close. When you hear those communications, at least back in that era, you can tell ATC are trained only in what good pilots would and should be doing. They can't get their head out of the box that someone could be doing something bad and that's why the transponder is off. It's not hard to imagine drug runners back in the day were able to outfox the law, unless the law used dedicated airborne resources to track the drug runner.
Any seasoned drug smuggler will answer, Hell, Yeh! Do it all the time!” 🤣🤣🤣
This is very well explained (Not a pilot but a RF Guy). "Flying Under The Radar" in battlefield for drug smuggling operation I think would be quite different/difficult. Down looking Radars from above would make un-detected low flying very hard. AWAC or better yet a hand full of these small NEO satellites "Space X" would be able to catch a lot of anything. But I do like the explanation.
Both primary, secondary/ADS-B have a lot of low altitude holes in their coverage. You need to know where the ground systems are located and what the terrain is. A composite aircraft is preferred to address primary radar and a direct pilot means of removing power from your transponder for all the other stuff.
I really prefer these long (normal) form videos! Please keep it up!
Also i would like to see a follow-up video explaining all the weirdness of (primary) radar systems, like reflections, ghosting an the like, and how controllers know which is actually the real target when there is no secondary radar information!
Maybe you could also mention/explain how the (US-?) military actually can detect stealth aircraft by interconnecting multiple different ground stations.
Commercial flights within the EU use the Mode S a lot. They all get the squawk 1000 in that case IIRC. But that's not the case with the flights e g. between the EU and UK
Thank you for the amazing videos Captain Joe! Keep up the good work!
How I love your videos. And the 'Remove before flight' hang tag of course 🙂
Interesting that it is now called “secondary radar” as we called it “Identification Friend or Foe” when I worked on military radar. And it really isn’t radar at all as it relies on responses from the aircraft’s transponder.
Thank you Captain Joe 👍
Sir can you please tell me that south african pilot license has value in all other countries?
Grand Theft Auto V has a mission where Trevor has to fly low in order to avoid being detected in a no-fly zone and you can also fly under bridges with a small two-engine plane.
Thanks for the info :)
Gracias por el nuevo aprendizaje capitán Joe ❤
De como envitar él radar by como es su funcionamiento 😊
Love ur show, I watch you and Mentour pilot. Both are equally informative and entertaining. Keep up the good work.
Thanks! Don't know the other channel but appreciate your comment!
This is just the video I needed. Thanks Captain Joe!
3:50 You almost say "der Aircraft" 😁
l'm watching some vídeos of his beginnings, and l have to say they are really Great. Now l can understand some comments. l see that you have taken t'hem Up again . And continues in the same line of infirmative and interesting . l loved the video .
Thank you!
Well, there goes my career plans... 😢 I hear they're paying big money to get rid of Pablo Escobar's hippo colony these days, so maybe...
He Joe. I just wanted to know why the technology in commercial aircraft seems so dated. I see the instruments that modern aircraft have and it just seems old
Wait a minute... I can still see 3 stripes on the uniform. In an older video in the stripes of pilot uniform you said that you were nearing promotion to captain. What happened?
The title 😂😂😂😂
I know that this is a channel about aviation but I was watching your video about birds flying into planes and saw that you had the Falcon from Star Wars on your wall. I would like a fun video about aviation in the Sci-Fi genre and which vehicles would you like to fly in Sci-Fi. I hope you consider this, please! Thank you! I love your videos I have learned a whole lot from your videos about aviation!!
@CaptainJoe... I don't have a cell phone to get a text nor do I know how to DM from You Tube. So what does this comment mean. And what did I win if anything? Thank you!
Very informative videos! Thank you.
I recently moved my house and its close to flightpath, its a tall rise and I can see almost all takeoffs and landings. I have noticed that while taking off the vertical height between my floor and flight is quite high, but while landing, its almost as close to my balcony. Is there any particular reason for that?
It's time to be promoted!!
For sure Radar DOES NOT use omnidirectionnal antennas as already commented by William Harvey.
Best regards,
some Electrical Engineer and Radio Amateur from Hamburg, Germany.