hacking

	==Phrack Inc.==

	Volume Four, Issue Thirty-Eight, File 6 of 15

	_____ BEATING THE RADAR RAP _____
	/ / \ / / \
	( 5/5 ) Part 2 of 2 : "The Technical Side" ( 5/5 )
	\_/___/ \_/___/
	by Dispater
	______________________________________________________________________________
	\| \|
	\| Introduction \| Welcome to the second installment in this series where we
	\|______________\| will briefly explore some of the technical sides to the
	operations, error analysis of the police traffic RADAR
	unit, the basics of how this technology was developed, then how it was
	implemented, a list of common RADAR errors, and finally the technical analysis
	of various types of traffic RADAR by National Highway Safety Administration.

	RADAR stands for Radio Detecting And Ranging. A traffic speed RADAR works
	under the principle of physicals called the "Doppler effect." This theory
	means that when a signal is reflected off of an object moving toward you, the
	signal will be at a higher frequency when it is closer to you than when the
	object is farther away or at the initial position. So the "Doppler effect" is
	THE basis for the use of the traffic speed RADAR.

	Right now in the United States, there are three bands that are allocated by the
	Federal Communications Commission (FCC) for "field disturbance sensors." These
	three bands have non-technical names, and all operate in the GigaHertz range
	(GigaHertz is a measure of frequency, i.e. 1 GHz = 1 billion cycles per
	second). The following is a list of the RADAR bands (as a point of reference
	FM radio modulates at 0.088 GHz to 0.108 GHz).

	:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
	BAND : FREQUENCY NOTE ABOUT SPECIFIC BAND
	:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
	X-Band : 10.525 GHz This is the frequency in which most RADAR units operate.
	K-Band : 24.150 GHz K-Band was developed to give a longer range of the beam.
	Ka-Band : 26.450 GHz This bandwidth is primarily for use with RADAR units
	that are used for "photo-speed traps."
	:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

	"So if RADAR is so unreliable," you ask, "why don't we have planes crashing on
	a daily basis?" In the first place, TRAFFIC RADAR operates on a COMPLETELY
	different basis than, say, the type of RADAR that tracks weather or airplanes.

	The technology of traffic RADAR can in no way be compared to the accuracy of
	other types of RADAR. Traffic RADAR does NOT "sweep" like a regular RADAR.
	"Sweeping" means that the RADAR is picking up every single return signal it
	gets and plots them proportionally on a two-dimensional cathode ray tube. On
	the other hand, traffic RADAR uses a stationary beam. Also, traffic RADAR does
	not use a modulated beam like regular RADAR; it uses a constant beam. ***This
	is an important distinction because this means that if there are multiple
	images, the constant RADAR beam cannot distinguish between them!***

	Furthermore, traffic RADAR is limited to things such as size. It must be able
	to fit inside a patrol car and it is also subject to cost. That means a
	municipality usually picks up the lowest bid it can get from various
	manufacturers.
	______________________________________________________________________________
	\| \|
	\| Implementation of Traffic RADAR \| It is important to note at this time that
	\|_________________________________\| while government standards for accuracy
	for military and commercial airline RADAR
	exist, traffic RADAR is NOT subject to ANY government standards whatsoever. An
	attempt was made to do this by the police and two government agencies, but were
	refused any type of compliance with traffic speed RADAR manufacturers and the
	Reagan administration.

	In the late 1970s, there was wide-spread publicity of about RADAR errors,
	including the well known tree clocked at 86-MPH in Florida. So, in 1979 the
	National Highway Safety Administration (NHSA) assigned to the National Bureau
	of Standards the task of testing all brands of traffic RADAR in use at that
	time for the purpose of discovering the source of these errors and proposing
	federal standards to eliminate them. In January of 1981, the proposed
	standards were published in the Federal Register. However, the Reagan
	administration took no action on the proposal (the last part of this file
	contains the profile from this report of various RADAR units).

	After THREE years of government inaction on the problem, the International
	Association of the Chief of Police (IACP) provided non-government standards by
	which all traffic RADAR units could be tested to assure accuracy: Volume I of
	the standards was published in April, 1984 and Volume II in June, of 1984.

	In June of 1986, the traffic RADAR manufacturers announced the formation of
	their own trade association, saying that they would not submit traffic RADAR
	units for IACP testing! Instead, they said they would use their own standards.

	So far, NO ONE has any idea of what these standards are; not the police, not
	the government and, most importantly, not the public! Basically, there are no
	performance requirements or standards for traffic RADAR and the claims of
	86-MPH trees and 28-MPH houses cannot be refuted.
	______________________________________________________________________________
	\| \|
	\| Common Traffic Radar Errors \| Below is a list of common errors and how they
	\|_____________________________\| occur. This is the part of the article that
	must be used in conjunction with the previous
	file in this series. You must attempt, while pleading your case, to tie in
	some of the following errors to the situation you found yourself in when you
	got your speeding ticket. See Phrack #37 file #5 for details.

	"The Look-Past Error" Even when the RADAR operator aims his gun properly, the
	RADAR is subject to this type of error. This is caused by the RADAR reflecting
	off of a larger surface area in the background rather than the smaller
	reflective surface in the foreground. Evidence of this the Look-Past Error was
	printed in the October 1979 issue of "Car and Driver." The author measured the
	effectiveness of KR11 RADAR system against various vehicles. The author showed
	that the typical sedan did not show up on the RADAR until it was less that 1200
	feet away, however, a Ford 9000 semi tractor trailer could be picked up at 7600
	feet.

	"The Road Sign Error" Due to the reflectability of microwaves, road signs,
	buildings, billboards, large trees, and other stationary objects are a source
	of errors.

	"Radio Interference Error" According to the Texas Department of Public
	Safety, "UHF frequencies broadcast today can force RADAR to read various
	numbers when transmitted within the area." This type of interference could
	come from the radio within the patrol car, citizens band radio, or television
	stations.

	"Fan Interference Error" When the antenna is mounted inside the patrol car,
	"RADAR will have the tendency to read the pulse of the fan motor (air
	conditioner, heater, defroster)." This is a statement provided by the Texas
	Department of Public Safety who conducted a study of RADAR guns in 1987. The
	Texas Department of Public Safety offered no safeguard for this error.

	"Beam Reflection Error" Since microwaves are so readily reflected, the Texas
	Department of Public Safety cautioned mounting the antenna within the patrol
	car. One instructor said, "It is possible that a reflective path can be set up
	through the rear view mirror that will produce RADAR readings on the vehicles
	behind the patrol car when the RADAR is aimed forward. And those vehicles can
	be either coming or going since traffic RADAR cannot distinguish between the
	direction."

	"Double Bounce Error" Again, since microwaves are easily reflected, the
	operator must be aware of a "bad bounce" and an ordinary reflection. And, as
	stated before, since large objects are more efficient than smaller ones,
	microwaves are attracted to them more. So, in effect, you could have an
	initial RADAR bounce off of the target vehicle, then from the target vehicle to
	a house or a truck going the opposite direction, and finally back to the patrol
	car. This error will mathematically get larger the slower the target vehicle
	is moving.

	"The Cosine Error" This is a mathematical error that takes place when the
	RADAR gun attempts to calculate the trigonomic equation that is programmed into
	it. The RADAR gun measures the angle at which the target enters a point and
	then exits a point (i.e. 25 degrees). The cosine of 25 is .9063. The RADAR
	gun was designed to calculate the speed of the patrol car by multiplying the
	speed of the patrol car (i.e. 50 mph) and the cosine of the angle (.9063) and
	it gets the false speed of the patrol vehicle as 45mph. Therefore, when you
	subtract the patrol speed from the target speed (i.e. 50, the same as the
	patrol car) you get the false sense that the target vehicle is traveling 5mph
	faster than the patrol car.
	______________________________________________________________________________
	\| \|
	\| Technical Analysis Report \| Below is a copy of the report mentioned above
	\|___________________________\| was conducted by the NHSA. But first I will
	explain what some of the criteria were under the
	testing conditions. It is also important to note that ALL RADAR units were
	subject to "panning error" except the CMI Speedgun-6 and Speedgun-8 models.
	Panning error occurs when the RADAR antenna is aimed at it's own display
	console. Unintentional errors of this sort can be eliminated when police
	officers are given adequate training.

	TEST UNIT : Model and manufacturer of the police speed RADAR
	unit in question.

	BAND : The short hand used for determining the broadcast
	frequency of the RADAR unit. X-Band is 8.2-12.4 GHz.
	K-Band is 18.0-26.5 GHz.

	BEAM WIDTH : The number that is 1/2 of the actual beam width.
	In other words, if a RADAR manufacturer says the beam
	width is 24 degrees, the actual beam width is
	48 degrees. Very deceptive, eh?

	SHADOWING ERROR : This occurs in moving mode only. It is the result
	of the RADAR mistaking another vehicle for it's
	ground reference and adding speed to the target
	reading.

	POWER SURGE : This occurs when the RADAR unit is first turned on.
	This also occurs when the "kill switch" is used to
	defeat RADAR detectors. Lag time for kill in the
	moving mode ranges from 1.5-5 seconds.


	EXTERNAL INTERFERENCE : The NBS test only used CB radio and police-band radio
	for "external interference." There are many other
	kinds of outside electromagnetic interference that
	may effect police RADAR.

	INTERNAL INTERFERENCE : Internal interference "may be caused by ANY
	electrical component or accessory in the vehicle,
	especially when the patrol car's primary power source
	is used to operate the RADAR.

	[It should be noted that TWO of MPH's K-55 RADAR units were tested. This
	demonstrates that each RADAR unit can contain its own quirks regardless of the
	fact that it can be from the same model from the same manufacturer.]
	_______________________________________________________________________________

	NATIONAL BUREAU OF STANDARDS SUMMARY ON TRAFFIC RADAR
	_______________________________________________________________________________

	TEST UNIT BAND BEAM WIDTH SHADOWING ERROR
	- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
	Kustom Signals MR-9 K 13.3 Minor



	POWER SURGE EXTERNAL INTERF. INTERNAL INTERF.
	- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
	Switch-ON gave CB radio caused false CB radio caused
	stray reading of 7mph readings of up to 25' erroneous readings
	_______________________________________________________________________________

	TEST UNIT BAND BEAM WIDTH SHADOWING ERROR
	- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
	MPH Industries K-55 X 20.4 Added 12mph to target in one
	(first of two units) test


	POWER SURGE EXTERNAL INTERF. INTERNAL INTERF.
	- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
	No valid reading for CB radio caused false CB radio many
	2.4 sec in moving mode readings of up to 20' erroneous readings
	_______________________________________________________________________________

	TEST UNIT BAND BEAM WIDTH SHADOWING ERROR
	- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
	MPH Industries K-55 X 24.6 Increased target speed 12-15mph
	(second of two units) about 20% of the time


	POWER SURGE EXTERNAL INTERF. INTERNAL INTERF.
	- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
	2 sec delay in moving mode, CB radio caused false CB radio cause many
	2.5 sec in stationary mode alarms up to 175' away erroneous readings
	_______________________________________________________________________________

	TEST UNIT BAND BEAM WIDTH SHADOWING ERROR
	- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
	Decatur MV-715 X 17.5 Added 8-23mph to target in
	repeated testing


	POWER SURGE EXTERNAL INTERF. INTERNAL INTERF.
	- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
	No valid reading for Not effected by external Extreme interference
	2+ seconds in moving mode CB radio from heater fan,
	ignition, & CB radio
	_______________________________________________________________________________

	TEST UNIT BAND BEAM WIDTH SHADOWING ERROR
	- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
	CMI Speedgun-6 X 18.8 Very severe, added 12-20 mph
	to target

	POWER SURGE EXTERNAL INTERF. INTERNAL INTERF.
	- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
	7 sec delay in moving mode, Not effected by external CB radio and police
	2 sec delay in stationary CB radio radio boosts
	readings 20mph
	_____________________________________________________________________________

	TEST UNIT BAND BEAM WIDTH SHADOWING ERROR
	- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
	CMI Speedgun-8 X 18.6 target traveling 41mph shown as
	74mph; target 30mph shown as
	41mph

	POWER SURGE EXTERNAL INTERF. INTERNAL INTERF.
	- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
	2 sec delay in moving mode, Not effected by external No adverse effect
	1.2 sec delay in stationary CB radio noted
	_______________________________________________________________________________

	TEST UNIT BAND BEAM WIDTH SHADOWING ERROR
	- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
	Kustom Signals MR-7 X 14.3 No effects noted


	POWER SURGE EXTERNAL INTERF. INTERNAL INTERF.
	- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
	25.4 sec delay in moving mode, Not effected by external Police band radio
	0.6 sec delay in stationary CB radio caused intermittent
	increases of 10mph
	______________________________________________________________________________
	\| \|
	\| In Closing... \| I hope you have learned a little about how police speed
	\|_______________\| RADAR operates, the errors that they frequently incur, and
	possibly a way to avoid the highway robbery that occurs
	each time Officer Friendly decides to make a little extra dough for his "job
	security."

	Also, if you are interested in obtaining cheap traffic RADAR equipment to play
	with, you can write to: AIS SATELLITE INC., 106 N. Seventh Street, Perkasie,
	PA 18944. You can also call them for a catalog at (215)453-1400 or place
	orders at (800)AIS-2001.
	______________________________________________________________________________