newbie@inmet (08/18/89)
** From "Herrington", the Enthusiasts Catalog **
AMBUSH DETECTOR TRACKS POLICE PLANS OVERHEAD --
WARNS YOU WHEN THERE'S A BEAR IN THE AIR!
OVERHEAD SURVEILLANCE -- Your speed is being clocked
from above by a growing fleet of police-owned Cessna 172's
and 182's. They don't use radar (it can't be used from
airplanes), just a simple stopwatch, so your radar detector
won't help. And by the time you notice the tell-tale white
hash marks painted every 1/4 mile along the Interstates,
it's too late! Using aircraft surveillance, troopers
typically quadruple their tickets-per-hour versus radar
(8/hr vs 2/hr!). Ohio alone has a fleet of 10 Cessnas and 3
helicopters, with more on order. And in Florida, 1/4 mi.
markers have been painted on 140 miles of continuous miles
of Interstate. Clearly new technology is need to warn you
of spies in the sky!
A TRACKING COMPUTER -- Spybuster detects aircraft, not
police radar! Highly specialized SMD circuitry operating at
1-2 gigahertz [What I think they mean is that the thingy
receives signals over that frequency range. If, however,
they have built a computer with a clock speed of 2 GHz, I
would like to know more...] receives signals from the FAA's
ground-based aircraft surveillance system. As these signals
reflect off airplanes, Spybuster locates and tracks with
military precision [Well, that isn't saying much is it?
Does anybody recall the precision of the DIVAD?!?] any plane
within a 6 mile radius of your car (scans a full 360 deg.)
[Thanks. I was always confused about how many degrees were
in a complete radius]. With more than one plane in the
area, Spybuster locks on to the closest one (police planes
operate at a low 2000-5000'). It then computes that plane's
closing rate relative to your position, ignoring fast-moving
747's and jet fighters. Since surveillance Cessnas operate
at only 100-140 mph [So, theoretically, I could out run one
if I was going, oh, say 160...], Spybuster warns you
immediately of any plane "loitering" in your area, or
tracking a parallel course. Spybuster is occasionally [sic]
fooled by an innocent civilian aircraft, but has proven
uncannily accurate in identifying police planes before they
get into position to clock your speed!
TARGET RANGE READOUT -- Spybuster's power switch
performs a self-test [Ok. How's it do that? Must be a damn
complex switch.] and permits muting of the audio alert. The
second green LED is the Tracking Indicator, and lights only
when Spybuster has locked on to a suspect aircraft. [When
will the surface-to-air missile option be available?] The
4-segment Range Readout then flashes in sequence as the
target plane or helicopter closes in. Variable Range
Control lets you set the distance at which Spybuster alerts
you. So when the audio is triggered, and the Range Readout
begins to sequence, there's probably a Bear in the air!
...
Price: $299
---------------------------------
Well, all I can say is wow! By the way, I added the
comments enclosed in brackets. How's that look for
stimulating some "conversation"?
- Chris Newbold
sampson@attctc.Dallas.TX.US (Steve Sampson) (08/19/89)
A couple of thoughts on the Spybuster: 1) With that frequency range it probably uses the ATC Transponder which transmits at 1090 MHz (1.09 GHz), and 2) It doesn't reflect off the aircraft, it's transmitted by it. 3) It's probably an omnidirectional antenna (which has 360 degree coverage) since no mention was made of an azimuth indicator. Would this then be a 1090 MHz receiver with a signal strength meter and alarm threshold control? The aircraft actually sends a burst of replies to ATC every time the Transponder is interrogated. By comparing the amplitude of the last burst with the amplitude of the current burst would then be an indication of closing/opening rate. Just thinking out loud...
hugo@bigtime.fidonet.org (Hugo) (08/21/89)
That ought to get things going, thanks a lot, Chris. I was,
unfortunately unable to find my copy of the 'tres yup' catalog. By the
way, what was the catalog?
--
Larry Hughes
Domain: hugo@bigtime.fidonet.org
UUCP: ...!{tektronix, hplabs!hp-pcd}!orstcs!bigtime!hugo
via Big Time Television (bigtime.fidonet.org, 1:152/201)john@anasaz.UUCP (John Moore) (08/23/89)
In article <17100002@inmet> newbie@inmet writes:
] A TRACKING COMPUTER -- Spybuster detects aircraft, not
]police radar! Highly specialized SMD circuitry operating at
]1-2 gigahertz [What I think they mean is that the thingy
]receives signals over that frequency range. If, however,
]they have built a computer with a clock speed of 2 GHz, I
]would like to know more...] receives signals from the FAA's
]ground-based aircraft surveillance system. As these signals
]reflect off airplanes, Spybuster locates and tracks with
]military precision [Well, that isn't saying much is it?
]Does anybody recall the precision of the DIVAD?!?] any plane
]within a 6 mile radius of your car (scans a full 360 deg.)
...miscellaneous wisecracks removed...
With more than one plane in the
]area, Spybuster locks on to the closest one (police planes
]operate at a low 2000-5000'). It then computes that plane's
]closing rate relative to your position, ignoring fast-moving
]747's and jet fighters. Since surveillance Cessnas operate
]at only 100-140 mph [So, theoretically, I could out run one
]if I was going, oh, say 160...], Spybuster warns you
]immediately of any plane "loitering" in your area, or
]tracking a parallel course. Spybuster is occasionally [sic]
]fooled by an innocent civilian aircraft, but has proven
]uncannily accurate in identifying police planes before they
]get into position to clock your speed!
This actually looks like a fairly practical technology within
certain limits: the aircraft has to be within range of the
FAA IFF interrogator's, and there can't be too many aircraft around.
Here in Arizona many highways are out of range.
The ironic thing is that I would probably use one IN an airplane
as a collision alert detector. It's a strange triumph of free
market over government control that this device is available
for $299, and would be quite useful as an airborne anti-collision
warning device with slightly different programming; meanwhile the
FAA has been twiddling around for 20 years and has yet to come
up with an effective and affordable airborne anti-collision device.
--
John Moore (NJ7E) mcdphx!anasaz!john asuvax!anasaz!john
(602) 861-7607 (day or eve) long palladium, short petroleum
7525 Clearwater Pkwy, Scottsdale, AZ 85253
The 2nd amendment is about military weapons, NOT JUST hunting weapons!newbie@inmet (08/23/89)
The copy was from "Herrington", the Enthusiasts Catalog. I thought I mentioned that at the top, but I might be wrong. - Chris
georgep@vice.ICO.TEK.COM (George Pell) (08/24/89)
In article <647@anasaz.UUCP> john@anasaz.UUCP (John Moore) writes: +In article <17100002@inmet> newbie@inmet writes: +> *** EXCERPTS FROM SPYBUSTER AD COPY *** +>A TRACKING COMPUTER -- Spybuster ..... receives signals +>from the FAA's ground-based aircraft surveillance system. +>It then computes that plane's closing rate relative to your position.... + +This actually looks like a fairly practical technology within +certain limits: the aircraft has to be within range of the +FAA IFF interrogator's, and there can't be too many aircraft around. +Here in Arizona many highways are out of range. + +The ironic thing is that I would probably use one IN an airplane +as a collision alert detector. I suspect that the skybuster only receives replys from aircraft interrogated by the Air Traffic Control Secondary Radar Beacon, and judges distance from signal strength. I do this with my Pro2004 scanner, and it's reception range is about 5 miles. Radar Beacon coverage at low altitude <1000 feet is spotty at best, and at ground level reception of the interrogator pulses would be totally undependable. The skybuster would require receiving both the interrogator and the reply pulses, and would have to measure the delay between them to actually calculate speed and distance. As for using the skybuster as an anti-collision alert detector, It would respond to my transponder located in my airplane, and would ALWAYS be issuing a warning. In order to be effective, you would have to turn off your transponder, which is not especially a good idea in high traffic density areas where you could use a collision alert. Keep in mind that a large percentage of private aircraft operating under visual flight rules follow freeways (freeways are called cement VORs). I expect that the skybuster would issue 99.9% false alarms. geo N29531 Cessna Cardinal "I Follow Freeways"
jmasters@pcocd2.intel.com (Justin Masters ) (08/24/89)
In article <647@anasaz.UUCP> john@anasaz.UUCP (John Moore) writes:
+
+The ironic thing is that I would probably use one IN an airplane
+as a collision alert detector. It's a strange triumph of free
+market over government control that this device is available
+for $299, and would be quite useful as an airborne anti-collision
+warning device with slightly different programming; meanwhile the
+FAA has been twiddling around for 20 years and has yet to come
+up with an effective and affordable airborne anti-collision device.
Wouldn't you just get the reflections from a plane at 0 feet? Seems to me it
would cancel out other planes' signals and get yours.
------------------------------------------------------------------------------
"This is the United States calling.
Are we reaching you?" - Pink Floyd Justin Masters - jmasters@pcocd2.intel.com
-----------------------------------------------------------------------------sampson@attctc.Dallas.TX.US (Steve Sampson) (08/24/89)
In article <791@mipos3.intel.com>, jmasters@pcocd2.intel.com (Justin Masters ) writes: > In article <647@anasaz.UUCP> john@anasaz.UUCP (John Moore) writes: > + > +The ironic thing is that I would probably use one IN an airplane > +as a collision alert detector. > > Wouldn't you just get the reflections from a plane at 0 feet? Seems to me it > would cancel out other planes' signals and get yours. > Well the common method used here is a suppression circuit triggered by your transponder. Various ideas come to mind if no suppression pulse is available on your transponder. Maybe something to switch the antenna to ground during replies based on detected power at the transponder antenna... A little more circuitry and maybe you could decode the Mode C replies? Anyone know the Mode C altitude report format - say a file of altitude vs code sent?
john@anasaz.UUCP (John Moore) (08/24/89)
In article <791@mipos3.intel.com> jmasters@pcocd2.UUCP (Justin Masters ) writes: ]In article <647@anasaz.UUCP] john@anasaz.UUCP (John Moore) writes: ]+ ]+The ironic thing is that I would probably use one IN an airplane ]+as a collision alert detector. It's a strange triumph of free ]+market over government control that this device is available ]+for $299, and would be quite useful as an airborne anti-collision ]+warning device with slightly different programming; meanwhile the ]+FAA has been twiddling around for 20 years and has yet to come ]+up with an effective and affordable airborne anti-collision device. ] ]Wouldn't you just get the reflections from a plane at 0 feet? Seems to me it ]would cancel out other planes' signals and get yours. You would obviously have to discriminate other signals from your own. That shouldn't be too hard - you know which one is yours by the signal strength. By comparing the timing between your signal and that from others, you can get an idea of distance. By putting the antenna on top of your plane (the transponder antenna is normally on the bottom), you reduce the overload caused by your own transponder. -- John Moore (NJ7E) mcdphx!anasaz!john asuvax!anasaz!john (602) 861-7607 (day or eve) long palladium, short petroleum 7525 Clearwater Pkwy, Scottsdale, AZ 85253 The 2nd amendment is about military weapons, NOT JUST hunting weapons!
ralphw@ius3.ius.cs.cmu.edu (Ralph Hyre) (08/25/89)
In article <4022@vice.ICO.TEK.COM> georgep@vice.ICO.TEK.COM (George Pell) writes: >As for using the skybuster as an anti-collision alert detector, It >would respond to my transponder located in my airplane, and would >ALWAYS be issuing a warning. In order to be effective, you would >have to turn off your transponder, which is not especially a good >idea in high traffic density areas where you could use a collision >alert. 'Easy' fix: Spybuster turns off your xponder for a short time when it's 'listening' (unless you're in a TCA, where controllers are presumably watching you, maybe you could put in a hack to infer TCA (or radar-controlled area) from the amount of time between interrogations,signal strength, and such.) [this would be the hard part to work out.] Cost would rise to >1K, since it's 'avionics' and probably has to be certified and such. -- - Ralph W. Hyre, Jr. Internet: ralphw@{ius{3,2,1}.,}cs.cmu.edu Phone:(412) CMU-BUGS Amateur Packet Radio: N3FGW@W2XO, or c/o W3VC, CMU Radio Club, Pittsburgh, PA "You can do what you want with my computer, but leave me alone!8-)"
michael@xanadu.COM (Michael McClary) (09/18/89)
In article <17100002@inmet> newbie@inmet writes: > >[] receives signals from the FAA's >ground-based aircraft surveillance system. As these signals >reflect off airplanes, Spybuster locates and tracks [] Ok, sounds like they're a radar receiver, taking advantage of the illumination provided by the existing air traffic control search radar, and requiring no active equipment in the plane. Listen for the ping from the transmitter, then the echo from the plane (which will always be later), and count the time between them. Doesn't give you true distance, but does provide a lower bound, and something roughly proportional to distance, for "is it closing" tests. Such a system would become confused if the airport radar was beside the road and the aircraft was between you and the radar site. (It would "sound" like it was right on top of you.) On the other hand, the reflection from the plane still decays inverse square, so it wouldn't false alarm very often. Cute!