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>>>>I was wondering if we (US) had concern for AQ ability to jam GPS--with or without Russian assistance- so we also wanted the GWEN system activated as a backup I have articles that say yes. I get conflicting commentary from people with the tech background though. Some say yes. Some say no. Notes below: Comments received on or by April 30, 2004 will be considered before final action is taken on the proposal. The proposal may be changed in light of comments received. This notice may be reproduced and recirculated by any interested person. Persons interested in being placed on a mailing list (electronic or hardcopy) for future Notices should submit a request to the Federal Aviation Administration at the address (or via email) listed above. Anthony M. Wylie Manager, Operations Branch, AAL-530 Issued in Anchorage, Alaska on March 15, 2004 ne2004.jpg A case of GPS jamming by a computer-test failure "Peter B. Ladkin" Mon, 27 Apr 1998 13:58:11 +0200 A colleague has pointed out to me that a confirmed case of significant GPS jamming is related at http://www.fcw.com/pubs/fcw/1998/0413/fcw-frontgps-4-13-1998.html A 30 Dec 1997 Continental trans-Atlantic flight lost all GPS signals as it descended south from Albany NY to Newark NJ for landing. Continental originally believed that the flight had been subject to intentional military jamming exercises. The FAA declared an `interference zone' of 300km, although they believed the jamming was localised around the Albany VOR navigation radio beacon. It turns out that the US Air Force Research Lab Information Directorate has a facility in Newport, NY, that tests antenna emission patterns. On 30 Dec 1997, they started a test of a GPS antenna with a 5-watt signal, stepping through frequencies. The tests are computer- controlled, and it wasn't noticed that at the end of the testing period the transmitter had not turned itself off. The lab discovered the problem through reading message traffic reporting a GPS outage in mid-January. The jamming period ran from 30 Dec to 12 Jan 1998. Peter Ladkin ladkin@rvs.uni-bielefeld.de http://www.rvs.uni-bielefeld.de [Typo fixed in archive copy. PGN] http://catless.ncl.ac.uk/Risks/19.71.html ----------------------------------------------------------- http://helicop.chat.ru/rus02.htm On THE CREATION OF GROUND JAMMING STATION WITH THE AMERICAN GLOBAL POSITIONING SYSTEM Of GPS NAVSTAR The American global positioning system NAVSTAR is widely used by NATO alliance countries. It possesses high accuracy, it is simple in the use and primeyaetsya in the aviation of all designations. The pilots to it of privykli and unconditionally they entrust. Besides the military and civil aviation GPS it is used for determining the coordinates of the sea and ground-based mobile objects, for example, of tanks. There are small movable receiving indicators for the infantry, by the size not more than binoculars. Are developed receiving indicators GPS by size wrist watch. Is developed the guidance system of cruise missiles and another weapon on signals NAVSTAR. Therefore Americans send 0 0N throughout the world the spies, who remove the geodetic coordinates of potential targets precisely in system NAVSTAR. Recently in Russia such spies were caught in the regions of the arrangement of atomic production near g.Krasnoyarska and in the Rostovskaya province. The receiving indicators of system are sold 0 0N throughout the world. For example, in Moscow them they sell in the representation of firm Trimble Navigation. The satellite GPS uses not only THE USA. It is accessible for any user. But here for using the military (more precise) channel it is necessary to possess the corresponding equipment and to know the code acting in this time, which THE USA can report to their military partners. In order to choke signals GPS, to know the secret military code not necessarily. Comparatively weak signals of the satellite system NAVSTAR can easily be muffled, emitting interferences from the Earth. American GPS operates at a frequency of 1575.42 megahertz (is possible the use one additional frequency in the military channel) and are used the phase-keyed (serrated) signals. In the article L.A.Ovcharenko and V.N.Poddubnogo the "noise immunity of the reception of the phase-keyed signals against the background of the most unfavorable interferences", printed in the release of the scientific journal "radio engineering" No 7-8 in 1992, dedicated to the problems of radio countermeasure, is shown that "most unfavorable" interference for GPS is the unmodulated carrier frequency (NG), detuned by relatively carrier approximately on 5 MHz. Specifically, this signal should be emitted in the ground jamming station. The range of jamming station is determined by radio horizon, but it is possible to considerably increase it, if we use effects of refraction, diffraction and distant tropospheric propagation, for which the transmitters must be powerful, and antenna - directed in the horizontal and vertical planes. It should be noted that the jamming station itself appears greatly grow prettier by purpose for the homing on the radio emission weapon. Therefore they should not be located them hereabout from the objects, whose defeat is undesirable. It is expedient to construct these stations for the work without the service personnel. From that fact that these jamming stations can be destroyed first of all, them it is expedient to construct as simpler as possible and cheaper, to what the absence of the need for the stabilization of their carrier frequency contributes. Therefore the application of simple self-excited oscillators with the nourishment without the rectifier is permissible. For the exception of use by enemy troops of the signals of the American satellite GPS NAVSTAR in the assigned region it is necessary to place in this region (in the distance from the guarded objects!) a large quantity of simple and cheap stations, switch oned remotely, in proportion to destruction by the enemy of those switch oned is earlier. ------------------------------------------------------------------------------------------------------------------------------ Read Valentin Kashinov comments at the end as well. According to his commnets, Iraq was jamming our GPS. This CNN article he references was written in 1999. Original message: http://cnn.com/US/9902/19/PM-Pentagon-satellite.ap/ Comments by Kashinovfollows: CNN: WASHINGTON (AP)--Civilianand military ships and planes couldfeeltheeffectofa Pentagon plan to disrupt its satellite navigation over North Carolina next week. The Defense Department will holdteststo prepare for potentiallossoftheGlobal Positioning System--amilitary-runnetwork which provideslongitudinalandlatitudinal coordinates for ships and planeswith appropriate receivers. The tests and accompanyingdisruptions could affect thecivilianshipsandaircraft that use the 24-hour network to help guide them. The Federal Aviation Administration and the Coast Guard issuednoticesFriday,cautioning pilots and ship operators against relying on GPS signals during certainfour-hourperiodsfrom Monday through Saturday next week. However, a spokesman for the U.S.Atlantic Command,which is running thetest,toldThe Washington Post heexpected"onlyminimal impact" on civilian users. Affected areas will vary greatlyaccording toaltitude.Forships,itwillinvolvea circular region withinaradiusof40miles centeredabout120mileseast of Wilmington, N.C. For planescruisingat40,000 feet,the affected area expands to a radius of350miles andreachesas far south as Vero Beach,Fla., and as far north as Sea Isle, N.J. Officials said therewerenoreportsof civiliansafetyproblems during previous tests held over North Carolina and Nevada. During the tests,military crewswillbe evaluatedon their ability to identify that GPS systems are not workingandonfindingother means of navigation. Dear colleagues: I am sending out my translation and its English CNN original on the tests scheduled in the US for the next week. Those are tests of the equipment designed to detect facts of jamming of GPS navigational signals. It confirms successful usage of such jamming signals against the American space-based navigational system GPS by the Iraqi. Earlier I passed instructions on the principles employed in such jamming stations to the Embassies of Iraq, Yugoslavia and others. Thanks to those jamming stations the winged rockets "Tomahawks" lose orientation and self-liquidate or hit the wrong targets. "Valorous" NATO pilots have no guts to fly in those zones where habitual for them and until recently reliable GPS no longer works. It is clear from the information received that Americans developed detectors of the fact of jamming and, possibly, heads for the class "air-ground" rockets for closing on the GPS jamming stations. To conduct life tests they, of cause,have to put such a jamming station into action that would create exactly such strike zone against GPS as was outlined in the information below. US must have testing grounds for pilots fearing to fly without GPS. Valentin V. Kashinov, corr.-member of International Slavic Academy, doctor of technical sciences. P.O. Box 570, 199397, Saint-Petersburg, Russia. ----------------------------------------------------------------------------------------------------------------------------- http://helicop.chat.ru/eng/eng02.htm http://helicop.chat.ru/eng/eng0.htm ON CREATION OF A GROUND JAMMING STATION AGAINST AMERICAN SATELLITE NAVIGATIONAL SYSTEM GPS NAVSTAR. American navigational satellite system NAVSTARis widelyusedby NATO coun tries.This system has high precision,simple to use and is used inthe aviationof all types.Pilots are used to it and tengt it.Aside from being used bymilitaryand civil aviation,GPSisusedforfinding coordinates of navalandgroundmobileobjects liketanks,forexample.Thereare small-size portable receivers-displays for infantry no larger than binoculars in size.Receivers of the size of a wristwatch are being developed. There is an already developed system for targeting wingedrocketsandotherweaponsystems using received from NAVSTARsignals.Forthatreason Americanssendspiesallover the world taking geodesic coordinates of potentialtargets specificallyforNAVSTARsystem.Recently such American spies were caught in engsia in theareas ofatomic production site near Krasnoyarsk and in Rostov district. Receiving systems are sold all over the world. For example,inMoscowtheyarebeing sold by the outlet of Trimble Navigation Company. Satellite GPS is used not only by the USA.Itis accessibletoeveryuser.Butin order to use military (more precise) channeltheusershould haveadequateequipmentand know the code valid for the duration ofthegiventime.Thatcode could be passed to military partners. For suppression of GPS signals,itisnot necessary toknowthatsecretemilitarycode. Relativelyweeksignalsof the satellite system NAVSTAR are easy to jambybeamingthejamming signals from the ground. American GPS works at frequency of 1575.42 MHz (it can use another frequency in amilitarychannel) and is using phase modulated (complex) signals. In theissuesNo.8-9ofascientificmagazine "Telecommunications and Radio Engineering" ("Radiotechnique" -inengsian)in 1992 was published an article by L.A.Ovcharenko and V.N.Poddubniy titled "Stabilityofreceptionof phasemanipulated signals on a background of most unfavorable jammingsignals".Thatarticlewas dedicatedto problems of radio defense.It shows that "the most unfavorable" jamming signal for GPS is anon-modulatedcarrierfrequencyofthe approximately 5 MHz spread spectrum.Thissignal should betransmittedfromagroundjamming station. The effectiveradiusofajammingstationis determinedbytheradiohorizon.Itcould be significantly increasedusingeffects of refraction, diffractionandlongdistance tropospheric spreading of radiowaves.Forthat transmitters should be powerful and their antennas directed in horizontal and vertical planes. It should benotedthatajammingstationby itselfisaverygood target for signal homing missiles. Therefore, they should not be located in proximity to the objects notdesirablefor becomingatarget.Preferably,thosestations should be designedtoworkwithoutservice personnel.Keepinmindthat those jamming stations could be annihilated before other targets and therefore they should be designed as cheep and simple as possible.Lack of need in stabilization of its carrier frequency contributes to thecost reduction. Therefore, usage of simple generators with self-excitement (simplestoscillator)withouta rectifier ispossible.Toprecludeusageof American satellite GPS NAVSTAR bytroopsofthe adversaryitisnecessarytoscatterinthe protected locality (in remotefromthedefended objectsareas)largenumber of simple and cheep stations.Theyshouldbeactivatedbyremote control in measuretootherstationsbeing destroyed. Valentin V. Kashinov, corr.-member of International Slavic Academy, doctor of technical sciences. P.O. Box 570, 199397, Saint-Petersburg, Russia.