nanog mailing list archives
Re: Analysis from a JHU CS Prof
From: Jeff Mcadams <jeffm () iglou com>
Date: Thu, 13 Sep 2001 17:24:25 -0400
Also sprach Leigh Anne Chisholm
I despise posting off-topic, but I want to say two things...
1. If a transponder is turned off, it doesn't mean that you don't show up on radar--a blip appears on the radar screen as long as you're high enough to be detected. If however you fly low enough, you can fly below the radar's detection capability. I don't offhand recall what height that is--it's been years since I was active as a pilot and prospective Air Traffic Controller.
That would depend on the distance from the transmitter...the farther from the transmitter, the higher you could fly and not be detected. Another issue is the efficiency of the transmitter and receiver at picking up the reflected energy. From what I understand, air traffic control radars are, in this day and age, really quite pathetic as true radars. They largely depend on transponder responses to be able to pick up aircraft, as even fairly large aircraft, at some distance from the transmitter, may only give a secondary (transponder) return, and not a primary (reflected energy) return. -- Jeff McAdams Email: jeffm () iglou com Head Network Administrator Voice: (502) 966-3848 IgLou Internet Services (800) 436-4456
Current thread:
- RE: Analysis from a JHU CS Prof, (continued)
- RE: Analysis from a JHU CS Prof John Fraizer (Sep 12)
- RE: Analysis from a JHU CS Prof Deepak Jain (Sep 12)
- RE: Analysis from a JHU CS Prof Hire, Ejay (Sep 12)
- Re: Analysis from a JHU CS Prof David Lesher (Sep 12)
- RE: Analysis from a JHU CS Prof Ron Buchalski (Sep 12)
- RE: Analysis from a JHU CS Prof Deepak Jain (Sep 13)
- Re: Analysis from a JHU CS Prof Joel Baker (Sep 13)
- RE: Analysis from a JHU CS Prof Deepak Jain (Sep 13)
- RE: Analysis from a JHU CS Prof Borchers, Mark (Sep 13)
- FW: Analysis from a JHU CS Prof Borger, Ben (Sep 13)
- RE: Analysis from a JHU CS Prof Leigh Anne Chisholm (Sep 13)
- Re: Analysis from a JHU CS Prof Jeff Mcadams (Sep 13)
- RE: Analysis from a JHU CS Prof Deepak Jain (Sep 13)
- Re: Analysis from a JHU CS Prof Joel Baker (Sep 13)
- RE: Analysis from a JHU CS Prof Matt Levine (Sep 13)
- RE: Analysis from a JHU CS Prof John Fraizer (Sep 13)
- RE: Analysis from a JHU CS Prof Leigh Anne Chisholm (Sep 13)
- Re: Analysis from a JHU CS Prof Owen DeLong (Sep 13)
- RE: Analysis from a JHU CS Prof Matt Levine (Sep 13)
- RE: Analysis from a JHU CS Prof Mikael Abrahamsson (Sep 13)