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.
sad to hear that. so is the instance gonna go down? anyone know how we should go about transferring our comments to another instance?