24-02-2023, 08:11 AM
I saw an interesting programme recently on stealth aircraft and they said that they are "invisible to radar," which is not quite true, but to all intents and purpose they are invisible to radar.
As you will know, a beam is sent out, it reflects off the aircraft and returns to the operator. A simple enough premise. But that does not work with the stealth aircraft. With these planes, instead of the signal returning to it's origin it is reflected off the aircraft at about a 45 degree angle and so does not return to the operator. Very clever, I thought. There are some very smart people out there.
But also of interest and in a similar vein; in WW1 radar had not been invented and so they had aircraft spotters on the coast and when enemy aircraft approached they would call the airfields and scramble the fighters, but invariably the warning came too late. But another smart fellow came up with another clever idea and they built oversized parabolic reflectors looking out over the English Channel and they could hear the approaching aircraft long before they saw them and were able to scramble the fighters in plenty of time to intercept the enemy. Very clever.
I am very interested in sound recording of all types and I have a small handheld parabolic reflector with a microphone set at the focal point about 30cm in front of the dish and I can hear normal conversations from a distance comparable to across the road. It is excellent for capturing bird songs from a distance and I don't frighten the birds away. I have some lovely recordings of Tuis (my favourite) singing away. Beautiful.
As you will know, a beam is sent out, it reflects off the aircraft and returns to the operator. A simple enough premise. But that does not work with the stealth aircraft. With these planes, instead of the signal returning to it's origin it is reflected off the aircraft at about a 45 degree angle and so does not return to the operator. Very clever, I thought. There are some very smart people out there.
But also of interest and in a similar vein; in WW1 radar had not been invented and so they had aircraft spotters on the coast and when enemy aircraft approached they would call the airfields and scramble the fighters, but invariably the warning came too late. But another smart fellow came up with another clever idea and they built oversized parabolic reflectors looking out over the English Channel and they could hear the approaching aircraft long before they saw them and were able to scramble the fighters in plenty of time to intercept the enemy. Very clever.
I am very interested in sound recording of all types and I have a small handheld parabolic reflector with a microphone set at the focal point about 30cm in front of the dish and I can hear normal conversations from a distance comparable to across the road. It is excellent for capturing bird songs from a distance and I don't frighten the birds away. I have some lovely recordings of Tuis (my favourite) singing away. Beautiful.
