If I remember my Clancy books right a lot of modern military radars are powerful af. They CAN detect things like birds, terrain, falling bombs etc, but that level of sensitivity creates a ton of noise for operators to sift through.
So computers apply filters so only things that meet certain parameters (speed, size, altitude) are visible to the operator. In theory a jet flying vertically at 0 ground speed could be invisible on a radar screen until they move horizontally again. The radar can see it but it isn’t showing it.
All of this is made tf up btw correct me if I’m too non credible
What you’re describing is called notching or hiding in the ground return/clutter that the radar sees by flying low to the ground and perpendicular to the aircraft you’re trying to hide from so the effective closure rate is the same as the offensive aircraft’s speed since modern radars use Doppler shift to locate targets. This strategy will not work on flying objects that are high enough to not be hidden in the ground clutter and especially if the defensive aircraft is higher than the emitter since it will be giving off a pretty strong return.
However other parts on aircraft give a huge return. Compressor blades from a jet engine or blades from a helicopter or drone would also show up like a flashlight in the dark.
The radar you’re talking about is a pulse-doppler radar. It doesn’t see things the same way your eyes (or a synthetic-aperture radar for example) do and it’s not down to filters. A P-D radar observes and measures the Doppler effect which only occurs when the object is moving and determines the contact’s velocity, heading and altitude based on that. A jet flying vertically at 0 GS would probably be detectable, although this would be difficult since, as you said, it’s not moving directly towards or away from the radar.
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If I remember my Clancy books right a lot of modern military radars are powerful af. They CAN detect things like birds, terrain, falling bombs etc, but that level of sensitivity creates a ton of noise for operators to sift through.
So computers apply filters so only things that meet certain parameters (speed, size, altitude) are visible to the operator. In theory a jet flying vertically at 0 ground speed could be invisible on a radar screen until they move horizontally again. The radar can see it but it isn’t showing it.
All of this is made tf up btw correct me if I’m too non credible
What you’re describing is called notching or hiding in the ground return/clutter that the radar sees by flying low to the ground and perpendicular to the aircraft you’re trying to hide from so the effective closure rate is the same as the offensive aircraft’s speed since modern radars use Doppler shift to locate targets. This strategy will not work on flying objects that are high enough to not be hidden in the ground clutter and especially if the defensive aircraft is higher than the emitter since it will be giving off a pretty strong return.
However other parts on aircraft give a huge return. Compressor blades from a jet engine or blades from a helicopter or drone would also show up like a flashlight in the dark.
The radar you’re talking about is a pulse-doppler radar. It doesn’t see things the same way your eyes (or a synthetic-aperture radar for example) do and it’s not down to filters. A P-D radar observes and measures the Doppler effect which only occurs when the object is moving and determines the contact’s velocity, heading and altitude based on that. A jet flying vertically at 0 GS would probably be detectable, although this would be difficult since, as you said, it’s not moving directly towards or away from the radar.