Questions tagged [radar]

Radar is a surveillance technology that uses radio waves to determine the range (and azimuth) of an aircraft. It works by measuring the time difference between a radio transmission and the echo or reply to that transmission. Radars are the most common surveillance equipment used by ATC.

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6
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2answers
311 views

What causes the radar phenomenon of ‘far-shore brightening’?

In Larry Milberry’s text on CAE (Canadian Aviation Electronics), in a discussion of the development of digital radar land mass simulation (DRLMS) for the Dutch Lynx mission simulator, far-shore ...
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116 views

How do Luneberg lenses hide a stealth aircraft's real signature?

I thought aircraft was supposed to be stealth and not show up on radar under the right conditions. This article says Removable Luneburg lens type radar reflectors are sometimes attached to military ...
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Tail Warning Radar on the P-51

One of the "features" of the P-51 was a tail warning radar that was supposed to let pilots know if an enemy fighter was on your tail. However, a P-51 pilot told me that they generally ...
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Why does a radar altimeter show negative values on the ground?

This applies to the Airbus 320 or Boeing 737, among others: Although it is useless on ground, the radar altimeter will repeatedly display a value (including negative) for a specific runway and airport ...
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Why bits are mixed up (interleaved) during ATC transponder mode A and mode C reply format?

In the image above from radartutorial.eu, we can see that the sequence of bits are c1 a1 c2 a2 c4 a4 during the reply of ATC transponder mode A. Why are the bits not transmitted like c1 c2 c4 then a1 ...
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129 views

Is it possible to use multiple primary radars to determine an object's location in three-dimensional space?

My question is this: if, for example, I have multiple radars across an area, tracking a particular airborne object, can I use the returns from the radars to determine the geographical location of an ...
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107 views

Weapon vs normal aircraft track

I've read that some radars can detect stealth aircraft or aircraft with low radar cross section but are not powerful enough to allow a "weapons" track or allow a missile or another aircraft ...
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How does the F-22 Raptor radar reflector work?

The F-22 Raptor (and other stealth aircraft) can be made more visible to radar by using radar reflectors, or in other words, radar cross section (RCS) enhancers. In the comments section of this answer ...
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Do jetliners carry radar that can detect other aircraft?

If not, why not? For example, if a civilian jetliner is flying at night over the Ocean, or a remote area with no airports/ground radar stations, and another airplane is also heading towards it on a ...
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1answer
294 views

How are both squawk and altitude transmited when operating a Transponder in Mode C?

I know that in Mode $3$ (which includes Mode A and Mode C) the aircraft transmits $12$ information pulses. That corresponds to $2^{12}=4096$ squawk combinations in Mode A which are sent to ATC to ...
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283 views

What is this part on the Me 262?

I have seen this part on a me 262 model kit but I don't know what it is... I've make some research on it but I find nothing! Maybe it can be radar, or a weapon? Do you know what is this? And also its ...
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How will the update from DO-260A to DO-260B improve safety and efficiency in air traffic management significantly?

From what I know, the version update from DO-260A and DO-260B offers new features such as on-ground vs airborne source selection logic, ADS-B failure annunciation, the split of the quality indicators ...
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1answer
83 views

Where is flight following available?

What local facilities are required for me to get flight following services? It seems that if I'm 100 miles from any control tower then I won't be able to get flight following. How close does a ...
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1answer
441 views

What is the broadcast rate of an ADS-B message?

From what I know, ADS-B (DF=17) message structure is 112 bits long. In terms of type of messages it transmits, there are aircraft identification, surface position, airborne position with baro altitude ...
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1answer
488 views

In Antonov An-225, why there are radioactive / nuclear signs?

Looking at some An-225 images, i see some radioactive signs near the nose radome. Why they are there? I'm sure it doesn't have a nuclear reactor on board or any nuclear medical equipment. The only ...
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What prevents the use of auxiliary radar installations to allow radar control and MSAW protection in areas that would otherwise be masked by terrain?

Both primary1 and secondary2 radar, while extremely useful (nay, indispensable) for modern aviation and air traffic control, are limited to seeing only aircraft in their direct line of sight; if there ...
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956 views

How big is the radar cross section of a modern glider?

I heard somewhere that modern glider made of plastic and composite materials are less detectable than other aircraft by primary radar. I wonder how much. What is the radar cross section of a typical ...
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1answer
257 views

Are old illegal air transfer methods still feasible today? [closed]

A retired soldier told me he used to know people who smuggled jewelries, hard drugs, guns and even people from middle eastern countries to Europe, specifically, Germany! Via planes! In fact, he said ...
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216 views

Why can’t a single-fan-beam radar determine the elevation angles of its primary targets?

A while back, I asked about the reason for one of the well-known limitations of most ATC primary radars (their inability to determine target altitudes).1 The answers boiled down to “single-beam fan-...
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How do people smuggle stuff with private airplanes? [closed]

I get it, the question seems as if I'm reaching out for answers from experienced smugglers! But no. As a matter of fact, I'm trying to get answers on air surveillance & security. Love it or hate ...
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1answer
87 views

Converting lat long & altitude into a line of sight target? [closed]

I want to design a long-range ADS-B receiver with a directional antenna (like a Yagi), but in order to maximize its range, I'll need to orient the antenna towards a target (plane) based on existing ...
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2answers
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Can a CIWS engage aerial targets?

Can a Phalanx-type Close-In Weapons System (CIWS) engage small aerial targets like drones, UAVs, rotorcraft? Is there any case that Phalanx was used against aerial targets?
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How does maneuvering affect radar detection of stealth aircraft?

Stealth aircraft like the F-22 and F-35 have very low radar cross sections. These planes have angles of their fuselage set-up in a way to deflect radar signals. As far as I understand another stealth ...
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616 views

What is garbling in the context of radar?

Garbling is a problem known to affect secondary surveillance radar (SSR). What is it and why is it a problem?
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What can cause a watchdog failure in an INDRA MSSR?

I am responsible for Mono-pulse Secondary Surveillance Radar (MSSR) system that resets itself after a watchdog failure. So far I have found the following: An unwanted number of replies are received ...
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Detection of solar balloons by ATC primary surveillance radar [duplicate]

I am curious whether a 30 cubic meter solar balloon made of black nylon and filled with ambient air would be detectable by the primary radar used by ATC in Continental Europe. Due to its size and ...
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Is there any current and/or upcoming technology that alerts Air Traffic Controllers in case of loss of aircraft separation?

Currently doing an assignment and it to analyse an accident where older atc systems could have been at fault. In 1995 there was an incident where two aircraft came closer than the then current ...
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3answers
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NEXRAD—why is it 2D?

If you paid attention to NEXRAD training, you know that the colors of pixels show the maximum activity at any altitude in that air column. (It’s a “composite” view.) NEXRAD itself samples in three ...
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1answer
392 views

How does an AMRAAM communicate securely with the aircraft that launched it?

From Wikipedia: It also incorporates a datalink to guide the missile to a point where its active radar turns on and makes terminal intercept of the target. An inertial reference unit and micro-...
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3answers
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How did pilots avoid thunderstorms and related weather before “reliable” airborne weather radar was introduced on airliners?

How did airline and or mail pilots avoid hazardous weather especially at night before airborne weather radar systems were in use?
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481 views

On ATC's radar, does an aircraft that loses its transponder simply disappear?

If you look at shows like Air Crash Investigation, which surely take some creative license in how events are portrayed, they often portray the disappearance of an aircraft, or specifically loss of its ...
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204 views

How are military aircraft directed to targets?

How would a controller, say, AWACS or ground radar, direct via voice an aircraft to the location of an airborne target? I've seen it in movies, but don't know if they where right, nor did I ...
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7answers
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Why do (or did, until very recently) aircraft transponders wait to be interrogated before broadcasting beacon signals?

An aircraft’s transponder transmits signals that announce (at the very least) the aircraft’s identity, altitude, and direction of motion (plus, for most newer aircraft, a whole slew of other useful ...
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2answers
833 views

ASTERIX category 240 fields placement in a UDP packet

I searched the placement of ASTERIX Category 240 radar video data fields in a UDP packet. But I cannot find any useful info. Is there a standard for this work?
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750 views

Are there any safety hazards when testing the F-16's fire control radar on the ground?

What are the procedures for ground testing an aircraft's fire control radar - for the F-16 or any other aircraft - and are there safety hazards associated with exposures to humans? Most importantly, ...
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4answers
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Can a helicopter mask itself from radar?

I have read somewhere that if a helicopter is traveling under 100 km/h and below 5 meters AGL then most radars will ignore it. From what I understand of this process, the radars can pick up things ...
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2answers
337 views

In track while scan mode of radar operation what are the methods to predict next position of target?

In a track while scan system (TWS) the algorithm states that the processor predicts the next position of the target and compares it with the actual position but what are the actual methods of ...
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2answers
650 views

What is the relation between clouds and radar effectiveness?

Recently, India's prime minister Narendra Modi commented on how cloudy weather can help a fighter jet escape from radar. Is there any technical reasoning to back these comments? Here is the quote ...
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5answers
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How is radar separation assured between primary and secondary targets?

Air traffic control radars come in two flavours, with most ATC centers using both and displaying the output of both on a single screen: Primary surveillance radar (PSR) is a true radar system, which ...
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1answer
1k views

How fast do the F-35 weapons bay doors open/close during combat ops?

(YouTube) I came across the following Norwegian F-35 video launching a live missile from its right bay door. Of course, opening the door and launching the missile drastically increases RCS, but it ...
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2answers
222 views

Will a Secondary Surveillance Radar be affected by a 300m high wind turbine?

60 wind turbines are located at a distance of about 30 km away from a Secondary Surveillance Radar installation; what will be the impact of this? My less than stellar knowledge of radar systems tells ...
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1answer
411 views

Why doesn't a radar-equipped Tower say “radar contact”?

Most/all of the control towers in my area have radar displays, and I know from visits that it shows all the same things as in TRACON miles away--even aircraft on the ground. I hear them occasionally ...
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1answer
414 views

Do any civilian aircraft use AESA or PESA for weather radar?

Are there any weather radars in civilian aircraft that uses active or passive array techniques? I know that the most of the radar used in the civilian aircraft use doppler effect and latest military ...
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5answers
2k views

Why can’t air traffic control radars determine the altitudes of primary targets?

There are two types of returns that show up on an air traffic controller’s radar screen: Secondary returns are not, strictly-speaking, radar “returns” at all, but, rather, signals automatically ...
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1answer
314 views

Do special procedures exist for commercial pilots flying over Russia?

Since Russia, and in particular the Asian part of it, is huge, I was wondering if there are special procedures for commercial pilots to follow over Russia (in particular and specifically Siberia and ...
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2answers
954 views

What are these FAA facilities in Seattle doing?

While walking in Discovery Park I discovered this radar dome with FAA notices on its fence. And not far away I cam across this small FAA signed radio antenna and shack. Any idea what these ...
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1answer
662 views

How does the radio altimeter reading change with the bank angle?

How does the radio altimeter reading change with the bank angle? Following example: Let's say, we're flying at 1000' AGL and a bank angle of 0° above a endless flat surface. The radio altimeter shows ...
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1answer
412 views

Why were these Hawkeyes flying in a circular pattern?

A couple of months ago I was near the Wallops Flight Facility in Virginia, when I saw 3 or 4 planes flying in a tight circular pattern. The planes were on the larger side, prop driven and had large ...
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1answer
172 views

Does the FAA prescribe radar cross-section requirements for civilian aircraft?

Are there any FAA regulations stipulating the minimum permissible radar cross section for civilian aircraft (i.e., making sure that civilian aircraft are at least such-and-such cross-section visible ...
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1answer
460 views

What does the ASDE-X ground radar unit look like?

Above is a picture of a primary / secondary surveillance radar combo (top is secondary, bottom is primary). What does the ASDE-X radar unit look like in real life?