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79 votes

How is radar used to help aiming a gun on fighter jets?

F-16 engineer here. This is from a great article about fire-control radar in fighter jets: For guns kills, if the aircraft has a radar lock on a target, it can accurately gauge range to the target, ...
Noddle's user avatar
  • 1,025
48 votes
Accepted

Why does a radar altimeter show negative values on the ground?

The zero reading is calibrated for main-wheel touchdown in a landing attitude. With the antenna forward of the main gear, it is, at that point, higher than it will be after the nosewheel is lowered to ...
Ralph J's user avatar
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39 votes

What is the significance of radar cross section (RCS) for air defense?

Its all about detection distance. Take a car and a beer can. You're 10 miles away, on an open plain. From there, you can't see either. Get closer...5 miles. Still can't see either. At 3 miles, you can ...
WPNSGuy's user avatar
  • 9,077
38 votes

How did pilots avoid thunderstorms and related weather before “reliable” airborne weather radar was introduced on airliners?

They looked out the window! If you are talking about a developing thunderstorm, especially during the day, they can be quite easy to see in front of you provided decent visibility. Here is some good ...
Dave's user avatar
  • 101k
34 votes
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Can a helicopter mask itself from radar?

Note that for advanced radar systems, moving helicopters might always be distinguishable from cars and other objects, due to the fact that helicopters have moving rotors. While I have no information ...
Erik A's user avatar
  • 456
31 votes
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What is this radar-like thing?

It is a wind tee; it serves the same function as a wind sock. It is designed to resemble an airplane from the air so that pilots overflying the field can more easily determine in which direction they ...
Devil07's user avatar
  • 8,574
31 votes
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Why does secondary surveillance radar use a different antenna design than primary radar?

With the secondary system, you are simply sending a one-way message from the radio tower to the transponder in the plane, and the transponder is transmitting a message back from the plane to the radio ...
Max R's user avatar
  • 3,808
29 votes

Why do (or did, until very recently) aircraft transponders wait to be interrogated before broadcasting beacon signals?

The Secondary Surveillance Radar system provides range in a method similar to primary radar: by measuring the time between the transmission of the interrogation signal and reception of the reply. The ...
user71659's user avatar
  • 6,636
28 votes
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Why does the radar dome on the E-3 have a white stripe down the middle?

The white strip is the metallic part which houses the electronics and serves as support structure for the antenna. The black part is basically a composite (fiberglass) shell, which covers the antenna. ...
aeroalias's user avatar
  • 100k
25 votes

How did the gyro gunsights of WW2 get the range and lead of a target?

You are seriously over estimating the technical capabilities of the time. The gun-sight is not much more than an intricate slide-rule. You had to feed it information about the target size/aircraft ...
Trevor_G's user avatar
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25 votes

Can a helicopter mask itself from radar?

The answer is yes (in most cases) but it has little to do with the helicopter itself. 5 meters (~16.5 feet) AGL is quite low to the ground. Chances are you are simply below the radar horizon for ...
Dave's user avatar
  • 101k
25 votes
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What is that airport equipment that looks like an SMR but rotates like a windmill?

That is a bird tracking radar antenna to detect and track birds in the vicinity of the airport. The vertical component is used to determine the bird's altitude. ROBIN's 3D Flex system consists of a ...
Bianfable's user avatar
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24 votes

What is this radar-like thing?

It's a lighted 'wind tee'. this website shows various wind direction indicators
Bageletas's user avatar
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23 votes

Did WWII fighters do a roll before engaging to identify themselves to radar operators?

For a radar to be able to detect/recognize/distinguish the electromagnetic signature of a "roll" requires very sophisticated real-time Signal Processing, that was not available until digital ...
Charles Bretana's user avatar
22 votes

Can a helicopter mask itself from radar?

The JSTARS (Joint Surveillance Target Attack Radar System) military radar developed and used from 1991 was particularly good at identifying helicopters. JSTARS was designed to identify moving objects ...
Ghedipunk's user avatar
  • 321
21 votes
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How can a single misplaced screw so massively increase a stealth aircraft's radar cross-section?

In RCS, size does not matter once you move beyond the scale of the wavelength of the radar. Therefore, the RCS of a panel with an edge length of 10 cm is (theoretically at least) the same as one of a ...
Peter Kämpf's user avatar
20 votes
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Does a secondary surveillance radar need the support of a primary surveillance radar?

SSR can work independently and this is quite common as well. Primary radars cost a lot to maintain, and as more and more planes are equipped with transponders, primary radars are being shut down. Many ...
60levelchange's user avatar
20 votes
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Radar, radio, and Biplanes

WW-II-era radar technology actually spans a very wide range of technologies, from British 20 MHz Chain Home with dipole antennas to German 24 GHz prototypes with parabolic disks that surprised its ...
Peter Kämpf's user avatar
19 votes
Accepted

What is in 'stealth paint' to absorb radar, and how does it work?

Stealth paint doesn't reflect radar, it absorbs it by converting it to heat which is absorbed and dissipated by the airplane's structure. Paint is only one of several Radar Absorbing Materials ...
GdD's user avatar
  • 54k
18 votes

How did pilots avoid thunderstorms and related weather before “reliable” airborne weather radar was introduced on airliners?

I´ll second John K´s recommendation of Fate is the Hunter for a first hand account of flying in the 30s and 40s. The style can be a bit too laden in floritures, trying to lend a certain mystique to ...
AEhere supports Monica's user avatar
16 votes

Which map projection is typically used on ATC radar screens?

I can only speak by experience, and this is relevant to PALLAS installed in Greek ACC and LGAV approach. What I concluded while discussing with ATCOs is that the projection used is gnomonic. ...
Stelios Adamantidis's user avatar
16 votes

Is it possible for ATC to see who’s transmitting on the radio on their radar?

A version of this has been implemented in some areas, such as the Maastricht Upper Area Control Centre, using radio direction finding equipment. The EUROCONTROL website provides an explanation of the ...
Zach Lipton's user avatar
  • 8,306
16 votes

Why do (or did, until very recently) aircraft transponders wait to be interrogated before broadcasting beacon signals?

I don’t get why most (or, until very recently, all) transponders don’t broadcast unbidden GNSS systems have only been commercially available relatively recently (compared to the timeline of aviation)....
Greg Hewgill's user avatar
  • 9,152
16 votes

How is radar used to help aiming a gun on fighter jets?

There are three components to an air-to-air gun solution, that must be taken into consideration by the engineers designing the gunsight mechanics, and well understood by the pilot utilizing the system....
Charles Bretana's user avatar
15 votes

Did the Stuka Ju-87 really have a radio altimeter? If so, when?

It looks like the actual date is 1942. The 'Nachtschlachtgruppen' aircraft were given Ju 87 D aircraft with numerous upgrades including the FuG 101 radio altimeter. This would make sense because to ...
Eric Urban's user avatar
  • 1,596
15 votes
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What causes the radar phenomenon of ‘far-shore brightening’?

Short answer Double-bounce backscatter or far shore brightening are radar industry phrases referring to the physical effect of multipath propagation: A target is illuminated by a direct ray and also ...
mins's user avatar
  • 74.7k
15 votes

What is the significance of radar cross section (RCS) for air defense?

Besides the problem of whether you can see it at all far enough away to have time to do something about it, you also have the problem that if you do build a radar capable of spotting bird-sized ...
Nullius in Verba's user avatar
15 votes

Can doppler radar be used to detect stealth aircraft by focusing on the characteristic flow field instead of the aircraft itself?

To a limited extent, yes, it's possible to detect the air disturbances left by aircraft. This NASA article studies the radar reflectivity of vortex wakes exhaustively. It's being proposed as a safety ...
Therac's user avatar
  • 27.6k

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