Отправлено: 29.08.10 22:57. Заголовок: подавление GPS приемников

Добрый вечер.
Есть ли возможность получить компетентный ответ (хотя бы в общем) от специалиста в области РЭБ?
Собственно интересует, возможно ли на нынешнем этапе эффективное подавление военных GPS приемников? С одной стороны подобные разработки есть и рекламируются, но "спецы" работающие с GPS говорят, что заявленные для таких систем дальность подавления в 100-150 км реальны только для гражданских изделий и для военных приемников эти значения будут составлять не более 150-200 метров. То есть, по факту, против ВТО с системами спутниковой коррекцией не эффективны.

 Отправлено: 11.12.10 23:18. Заголовок: http://www.insidegns..

 Отправлено: 11.12.10 23:49. Заголовок: FSL = 32.45 + 20Log1..

Free space loss FSL = 32.45 + 20Log10(F in MHZ) + 20log10(D in Kms)

dlja GPS 1500 mgz i 20 000 km = 182 db


The spot beam is ~20 dB more powerful than the whole Earth coverage beam
M-code signal at Earth's surface: –158 dBW for whole Earth antenna, –138 dBW for spot beam antennas.
***************************************************************************************
ili -108 dbm s 2013 goda
http://en.wikipedia.org/wiki/GPS_modernization<\/u><\/a>


+28-29 dbw EIRP na sputnike -182-184 db = -153-156 dbw ili -123 -126 dbm bez napr. antenni ,xoroscho korreliruet

 Отправлено: 11.12.10 23:58. Заголовок: The payload consists..

The payload consists of L-Band navigation signals in 25 channels separated by 0.5625 MHz intervals in 2 frequency bands: 1602.5625 - 1615.5 MHz and 1240 - 1260 MHz.

EIRP 25 to 27 dBW
*******************

na 2 db xuze chem y GPS poslednego bloka ,podnjat ne problema
no bez naprawlennix antenn ...


Wes sputnikow GPS narastaet ,a Glonass snizaetsja
********************************************

http://warfare.ru/?lang=&linkid=2332&catid=326<\/u><\/a>

Configuration: 3-Axis stabilized, 2 solar arrays
Lifetime: 10 years
Mass: 750 kg
Orbit: 19100 km x 19100 km, 64.8°

 Отправлено: 12.12.10 00:10. Заголовок: Powischenie nesusch..

Powischenie nesuschej w naprawlenii 20ghz/44 ghz Milstar/AEHF i ostronapr. antenni
(budut isp w GPS s 2013 goda i na 1.5 ghz) -
bolschaja ystojchiwost k postanowke pomex
(smotri wische st. IRE RAN)

Ewropejskaja tochka zrenija o wozmoznosti ispolzowanija C-Band /5.4 5.9 ghz/

http://www.insidegnss.com/auto/mayjune09-wp.pdf<\/u><\/a>

http://www.insidegnss.com/auto/julyaug09-wp-final.pdf<\/u><\/a>

http://www.insidegnss.com/node/1457#Baseband_Technologies_Inc_<\/u><\/a>
http://www.insidegnss.com/node/1582#Baseband_Technologies_Inc_<\/u><\/a>

 Отправлено: 12.12.10 00:18. Заголовок: Session A5, Paper #1..

Session A5, Paper #1

Simulation Study of UWB-OFDM SAR for Navigation Using a Kalman Filter
K. Kauffman, J. Raquet, Air Force Institute of Technology; Y. Morton, D. Garmatyuk, Miami University

Alternatives to GPS are necessary for robust navigation solutions. In environments such as urban canyons, indoor applications, or areas with active jamming, non-GPS based position and velocity sensors must be used to obtain or aid navigation solutions. There are a number of sensors that have been used for navigation, however in many situations these sensors do not operate well. The addition of alternative sensors allows the navigation platform to operate under more diverse environmental conditions.

In our previous work, we developed an ultra-wide-band (UWB) orthogonal frequency division multiplexed (OFDM) radar system prototype [1] with 500MHz baseband bandwidth.
--------------------------------------------------------------------------
The UWB-OFDM sensor exhibits many useful properties for navigation. Like other UWB systems, it has high resolution target ranging and localization when used as a synthetic aperture radar (SAR) [2]. The OFDM waveform has good potential for anti-jamming and multipath mitigation [3][4]. Using an active UWB-OFDM sensor allows for even greater anti-jamming capabilities over other sensors using RF signals of opportunity
----------------------------------------------------------------------------------------

. Since our prototype is software defined, the OFDM symbol is changeable on a pulse-to-pulse basis. This allows the spectrum of the signal to be modified in real time to avoid narrow-band interference, such as GPS. One obstacle in using UWB-OFDM for navigation is the high computational requirements for constructing SAR images in real-time. Our previous study developed an efficient algorithm for computing partial SAR images rapidly for real-time high resolution positioning of a small number of targets [5].

Recently, we developed and simulated a two-dimensional dead-reckoning navigation system based on an active, on-board UWB-OFDM sensor [6]. This initial work assumes that a single aerial vehicle (AV) moves along a fixed axis recording raw SAR data in a stripmap configuration, with random persistent scatterers located along the axis of travel. A sparse target SAR algorithm [5] was combined with a two-stage tracking and estimation algorithm to obtain both the AV and target positions in real time. In the first stage, the initial known positions of the AV and the AV-target range measurements obtained by the UWB-OFDM sensor are used to estimate targets locations. In the second stage, the newly estimated target positions are combined with existing and new range measurements to infer AV positions. Through this preliminary investigation, we demonstrated the feasibility of using the UWB-OFDM sensor as a navigation aid, under various ideal assumptions.

In this paper, we extend our previous work by making several drastic improvements. First, the two-stage estimation and tracking algorithm is replaced with a Kalman filter based approach. Second, an inertial navigation sensor is incorporated into the simulation. Third, more realistic models are used to replace some of the ideal assumptions used in previous study:

1. The persistent scatterers are replaced by conductive spheres modeled using Lorenz-Mie theory [7] to account for frequency-dependent distortion of the UWB waveform. 2. Swerling target models [8] are used to account for time-varying stochastic properties of the targetґs radar cross section. 3. The channel is modeled using realistic signal propagation path loss instead of a white Gaussian noise channel.

The paper presents the detailed implementation of new Kalman filter based estimation and tracking algorithm and analyzes the effects of the frequency and time dependent distortion in the measurement data due to the more realistic target and channel models. The estimated AV position is compared to the actual simulated flight distance. The position drift is calculated for varying conditions, such as target availability, target and channel model parameters, and received SNR. Performance evaluations demonstrate the robustness of the Kalman filter based approach. Quantitative comparisons of solutions generated by the new implementation with our previous two-stage approach will also be discussed.

[1] D. Garmatyuk, K. Kauffman, J. Schuerger, and S. Spalding, "Wideband OFDM System for Radar and Communications," in Proceedings of 2009 IEEE Radar Conference, Pasadena, CA, 2009. [2] D. S. Garmatyuk, "Simulated imaging performance of UWB SAR based on OFDM," in Proc. 2006 IEEE Int. Conf. on Ultra-Wideband, Waltham, MA, 2006, pp. 237-242. [3] J. Schuerger and D. Garmatyuk, "Deception jamming modeling in radar sensor networks," in Proc. 2008 Military Communications Conference (MILCOM), San Diego, CA, Nov. 2008. [4] C. Schexnayder, J. Raquet, and R. Martin, "Effects of Oversampling and Multipath on Navigation Using OFDM Signals of Opportunity," Proceedings of ION GNSS-2008, Savannah, GA, Sep 2008. [5] K. Kauffman, "Fast target tracking technique for synthetic aperture radars," M.S. thesis, Miami University, Oxford, OH, USA, 2009. [6] K. Kauffman, Y. Morton, J. Raquet, D. Garmatyuk, "Simulation study of UWB-OFDM SAR for dead-reckoning navigation," Proc. ION ITM, San Diego, CA, Jan. 2010. [7] A. Stratton: Electromagnetic Theory, New York: McGraw-Hill, 1941. [8] Skolnik, M. Introduction to Radar Systems: Third Edition. McGraw-Hill, New York, 2001.

http://www.ion.org/meetings/past/gps2002/A5.cfm<\/u><\/a>

 Отправлено: 12.12.10 20:42. Заголовок: The minimum value of..

The minimum
value of 20 dB J/S was chosen because C/A acquisition at
24 dB J/S is a common military requirement.
*************************************
The
maximum value was chosen because no GPS receivers can
track at 80 dB J/S against a WB jammer without
employing beamsteering,*nulling, or some other multielement
antenna technique.
****************

http://www.fas.org/spp/military/program/nav/labjam.pdf<\/u><\/a>

 Отправлено: 12.12.10 21:26. Заголовок: primer razrabotka wo..

primer razrabotka woenngo GPS priemnika (sponsori Air Force i US Navy) s J/S -120 sb


RF Applications

Two RF applications are under development - a high linearity, high dynamic range RF receiver, targeting GPS receivers and a clock synchronization chipset, targeting backplane applications.

High Linearity, High Dynamic Range RF Receivers: A monolithic chip is under development to enable operation of GPS receivers in the presence of jamming sources. This technology is very enabling in the context of hand-held applications and GPS guided munitions, in which a compact design is of the essence.

The NTK-Ironman-01 is a complete dual-channel global positioning system (GPS) front-end down converter. This low power CMOS IC integrates a low-noise amplifier (LNA), image rejection mixer, automatic-gain-control amplifier (AGC), secondary mixer, and clock buffer. External IF, baseband filters, and ADCs enhance flexibility. The device supports C/A, P(Y), and M codes.

This device provides the most versatile integrated front-end available. Two independent down converters per channel (shown below) gives it a wide range of supported frequency plans. Each mixer utilizes an independent external COTS synthesizer to generate the local oscillator (LO). Further, each down converter can be used for high side or low side mixing and operate on L1 and L2 simultaneously. Alternatively, both down converters can operate only on L1, L2 or L5, as is necessary when used with an adaptive antenna array.

The digital AGC allows the receiver to accommodate multiple wideband and narrow band jammers having a total power up to -13 dBm without clipping.

The device supports multichannel digital adaptive anti-jam signal processors providing wideband cancellation in excess of 50 dB. When combined with a GPS signal processor providing 70 dB A/J the RF ASIC will support GPS tracking with 120 dB J/S.

http://www.nu-trek.com/nu-trek/rf-applications.html<\/u><\/a>

 Отправлено: 16.12.10 15:17. Заголовок: July 13/09: Per an I..

http://www.defenseindustrydaily.com/Boeing-Wins-RD-Contract-for-High-Integrity-GPS-05000/<\/u><\/a>


Related Stories: Americas - USA, Boeing, C4ISR, Contracts - Awards, GPS Infrastructure, R&D - Contracted, Satellites & Sensors, Transformation


GPS IIF satellite
(click to view full)In July 2008, the Pentagon announced that Boeing’s Huntington Beach, CA facility would work on a “High Integrity GPS (Global Positioning System) Technology Concept demonstration,” under a $150+ million contract that runs until January 2011.

The European Space Agency has a similar program called EGNOS (European Geostationary Navigation Overlay Service), which is the ESA’s interim step until its competing Galileo GPS constellation can be built and deployed. EGNOS uses 3 satellites in geostationary orbit, correlating their information with GPS to improve civilian positioning accuracy from 15 meters to 2 meters. In contrast, the USA’s Office of Naval Research contract aims to leverage an existing commercial constellation: the low-bandwidth Iridium constellation of satellites. If their R&D project succeeds, it will create a GPS service that provides quicker positioning fixes, offers improved accuracy for military M-code users, and is more resistant to jamming and other forms of damage.

What is Iridium? Why is this such an important contract? How does a global satellite phone service end up improving the Global Positioning System? Could this program have important commercial spin-offs? DID offers answers, below…

The Rise and Folly of Iridium
HI-GPS: A Starring Role in A Different Global Vision?
HI-GPS: Theory and Practice
Contracts and Key Events [NEW]
Additional Readings covering Iridium, GPS, and related developments [updated]
The Rise and Folly of Iridium


Early Iridium phoneIn the early 1990s, the Iridium satellite constellation was touted as an example of strategic corporate vision. Its popularity in business schools has gone from strength to strength since then; unfortunately for Motorola, that popularity is now driven by its iconic status as a cautionary tale. The constellation was once part of Motorola’s ambitious plans for a global satellite phone service, with equity partnership arrangements and local landing points all around the world. The initial equipment and service would be expensive, but businesses could afford to pay $3,000 for a phone. Especially it meant that its executives and key projects could truly remain in touch any time, anywhere. In an era of globalized business, Iridium seemed like an idea whose time had come. Motorola took the plunge, even though the system required at least 66 satellites in orbit before it could fulfill its promise.

The single-minded commitment Motorola displayed in making this ambitious vision a reality, turned out to be its achilles heel. Despite its status as a significant manufacturer of mobile phones, Motorola never really reassessed Iridium’s business case once cellular phone infrastructure entered a boom phase all around the world. By the time the constellation had been designed, built, and launched, most urban locations around the globe were already covered by cell phones that offered global connectivity, and didn’t cost $3,000. Worse, Motorola’s offering had issues that included problems with satellite phone reception inside buildings, where business people often need to talk.

Motorola alone lost more than $900 million on the project, and the Iridium service entered Chapter 11 bankruptcy in 1998. Motorola’s engineers were transferred to Boeing for pennies on the dollar, as part of an investment consortium agreement that bought the Iridium service firm in December 2000.

Boeing now operates the 66 satellite constellation, but the Iridium satellites’ tiny bandwidth limits their usefulness. Although Iridium was built as a civilian constellation and remains so, its combination of key advantages and inherent limitations have left it with military voice traffic as a key customer.

The Iridium constellation is expected to remain in orbit until at least 2014, and will be followed by a higher-bandwidth Iridium Next series. These satellites are expected to cost Iridium about $2 billion to deploy, with full availability planned for 2016. The new satellites would be backward compatible with existing Iridium systems, while offering new features and a 5,000x bandwidth increase from 2400 bps to over 10 Mbps.

HI-GPS: A Starring Role in A Different Global Vision?


Navstar now
GPS Block IIA, IIR/M, IIF
(click to view full)Despite the proliferation of GPS devices in our cars, backpacks, bass boats, iPhones, etc., few people really understand the depth and breadth of GPS’ importance to the world. Bank automatic tellers and stock markets rely on GPS’ ultra-accurate timing service to record the exact times of transactions. Fields are farmed using paths set by GPS. Road and rail transportation networks rely on it for tracking the movement of freight. Some have described the 31 satellite NAVSTAR GPS system as the greatest success in the history of the US Air Force, and one can certainly make a convincing case for that proposition.

On the military side, GPS has become equally ubiquitous. The same freight tracking technologies used by logistics companies are used by the US military to track its own massive, and critical, logistics tail. Tanks use it to track the positions of friendly and enemy units via their Blue force Tracker displays. The soldiers beside them also use it to find their way or report their position using hand-held display units like DAGR. Cruise missiles use it to find their targets, and tail kits like Boeing’s GPS-enabled JDAM can turn any bomb into a precision smart weapon for under $40,000. With the introduction of the M982 Excalibur and M30 GMLRS rocket, even battlefield artillery has come to rely on GPS for guidance.

That proliferation is evidence of success, but it’s also a weakness in any complex system. When so many things are dependent upon just one node or service, the entire system’s stability becomes dependent on just one link in the chain. As the recent Chinese anti-satellite test proved, that link’s stability can’t be taken for granted. When the natural vagaries of cruel fate and chance are thrown into the mix, the rationale for a “high-integrity” GPS system that improves upon the existing constellation becomes clear.

Anyone who has used a hand-held civilian unit also understands the usefulness of faster satellite acquisition and position fixes. Now imagine that people are firing at you, or you’re trying to hide in hostile territory, while obtaining the signal. Jamming resistance is self-evidently useful, and so is improved accuracy.

Lockheed Martin recently beat Boeing for the $1.5 billion contract to build the first set of GPS-IIIA/B satellites, which offer some of these features. On the other hand, the first GPS-IIIA satellite is not scheduled to launch until 2014, older satellites will remain in the GPS constellation for more than a decade to come, and the issue of system robustness will remain no matter who builds the constellation.

Hence the ONR’s interest in the High Integrity GPS research project, also known as iGPS. It aims to leverage one of the things Motorola got right in Iridium: the satellites are very programmable.

HI-GPS: Theory and Practice


Iridium satelite
(click to view full)The High Integrity/ iGPS team includes Boeing Advanced Systems and Phantom Works, Iridium LLC, Rockwell Collins, Coherent Navigation and experts from academia.

In a way, HI-GPS may hearken back to the early days of space navigation systems. David Whelan, Boeing IDS’ Chief Scientist and its Deputy GM for Advanced Systems, reminded DID of the Naval Research Laboratory and Johns Hopkins’ Transit satellites, which began development in the late 1950s and served until 1996. Transit was a beacon tracking system in Low Earth Orbit (LEO), which relied on the doppler shift of the satellite’s signals to establish positioning.

Under HI-GPS, Iridium’s LEO satellites would work with Medium Earth Orbit (MEO) GPS satellites. Whelan did not specify the exact approaches under investigation, but correlation of GPS positioning with multiple correlated beacon tracking from Iridium satellites might be a useful possibility to study. Others surely exist, and an EE Times article suggested that signal relays that lever the Iridium satellite’s closer low-earth orbits might also be involved. What is certain is that any approach is likely to be based on new signals that can augment GPS, making more satellites available for positioning uses.

These research approaches have 2 key conditions they must meet, however, in order to work. One is that the GPS and auxiliary satellites’ exact positions relative to each other need to be known with some precision. Whelan says that Iridium’s engineering team has worked with Boeing to develop more precise algorithms and approaches for this purpose, and continues to do so.

The other sine qua non is that the satellites’ clocks must all be synchronized with extreme precision. This capability is required for GPS in any event, as the NAVSTAR system relies on correlating distinct, signature signals from each available satellite. To illustrate the scale of the problem, an error or misalignment of just 1 microsecond can introduce a positioning error of up to 1,000 feet. This is why the US Naval Observatory’s atomic clock in Washington, DC has been defined as the “master clock” for the entire GPS system, with subtle corrections made on a regular basis to the atomic clocks on each satellite and ground tracking station. Whelan says that Iridium has now achieved “perfect time,” via a very precise datalink calibration with allowed time channel.

That’s the theory. In practice, HI-GPS remains a research project whose outcome is uncertain. Whelan was adamant about not making any claims for the system just yet, until firm results that can back those claims up have been demonstrated. As a scientist and engineer, he is all too aware that any research engineering project always has some chance of failure.

This is especially true in a military context, where one must contend with the vagaries of enemy action on top of the inevitable engineering challenges. The ESA’s EGNOS is a localized service for civilian use, but the USA’s HI-GPS is envisaged as a global service that will focus on military uses.

If HI-GPS can succeed in meeting its goals by 2011, however, it would offer an important and welcome boost to the NAVSTAR military system. The nature of its approach would make more satellites available, in lower orbits, for very precise positioning uses. That would both improve system speed, and offer precise positioning resiliency if some of the satellites are disabled. All this is likely to be accomplished using a different signal, which would have to be jammed separately in order to fully jam GPS.

Which leaves the final question: what about the civilian front? Projects like EGNOS have proven that improved positioning has civilian value too, especially as GPS continues to embed itself in a wide range of civil technologies and functions. Whelan said that Boeing has asked itself whether HI-GPS would also have commercial value. The answer to that question can only be “yes.”

Converting a military research project to civilian use would require multiple approvals, however, from the project’s sponsors at ONR, to America’s National Executive Committee for Space-Based PNT, to possible approvals from national agencies like the Commerce Department, Department of Transportation, et. al. Issues of proven safety, as well as inherent issues of an enhanced global civilian signal’s usefulness as a military weapon, would certainly be raised. Then again, the rise of competing PNT/GPS systems may make the point moot by offering the same capabilities.

For now, civil adoption remains a long way off, and even military adoption is uncertain. What can be said with certainty, however, is that the idea behind HI-GPS is one that shows a lot of promise on both military and civilian fronts. This is a project worth watching.

Contracts and Key Events


Early Iridium poster
(click to view full)July 13/09: Per an Iridium/Boeing release, High Integrity GPS reaches 2 major milestones for the U.S. Naval Research Laboratory.

The first milestone involves on-orbit Enhanced Narrowband (ENB) software modifications to the Iridium constellation. Second-generation GPS-aiding signals can now be broadcast throughout the entire Iridium constellation. The team completed the ENB software upgrade on schedule and within budget, and will support a system-level demonstration later in 2009.

The second milestone was a demonstration in which a receiver on a moving vehicle used the technology to acquire a GPS signal, despite hostile jamming. David Whelan, Boeing IDS chief scientist and Phantom Works Deputy General Manager, explains why this matters:

“When a military GPS receiver is jammed, it cannot obtain a position fix, and movement only makes the situation worse. Even from a cold start, it took only minutes for the High Integrity GPS-aided receiver, in a moving vehicle, to receive the GPS signal while being jammed. Without assistance from the High Integrity GPS system, a position fix would never have been obtained.”

July 18/08: The Pentagon announces that Boeing’s Huntington Beach, CA facility will work on a “High Integrity GPS (Global Positioning System) Technology Concept demonstration,” under a $153.5 million cost-plus-fixed fee completion contract that runs until January 2011 (N000173-08-C-2074).

Work will be performed in Huntington Beach, CA (34.3%); Philadelphia, PA (17.3%); St. Louis, MO (1.5%); El Segundo, CA (12.6%); Cedar Raids, IA (12.3%); Bethesda, MD (15.3%); Washington, D.C. (5.4%); Ithaca, NY (0.5%); Chicago, IL (0.3%) and Burlingame, CA (0.5%), and is expected to finish in January 2011. This contract was competitively procured under Naval Research Laboratory Broad Agency Announcement 68-07-01. See also Boeing release | EE Times: “Boeing aims to combine GPS, Iridium orbiting networks.”

 Отправлено: 16.12.10 15:25. Заголовок: http://systems.cs.co..

 Отправлено: 16.12.10 16:03. Заголовок: 04-Aug-2009 14:29 UT..

04-Aug-2009 14:29 UTC

Related Stories: Americas - USA, Contracts - Modifications, Electronics - General, GPS Infrastructure, Other Corporation


DAGR GPS Receiver
(click to view full)Rockwell Collins in Cedar Rapids, IA received a $20.2 million contract modification to provide 81,622 DAGR hand-held GPS receivers and accessories to the US Air Force GPS Wing (GPSW/PK) in El Segundo, CA.

This contract modification is part of a $450 million DAGR follow-on contract (FA8807-09-C-0002) announced March 18/09 by Rockwell Collins. The company received its first order from the USAF under the contract that same month: 53,920 DAGR receivers and accessories for $87.5 million.

The DAGR is a handheld GPS receiver that provides position, navigation and situational awareness for US troops.

The receiver provides precise timing to synchronize tactical radios, missile platforms and other situational awareness navigation systems and includes a Graphical User Interface (GUI) that provides ease of use.

The DAGR design incorporates anti-jam improvements and denied GPS capabilities for worldwide enhanced battlefield protection. It is the first US handheld GPS receiver program to include the Selective Availability Anti-Spoofing Module (SAASM) security device. The Rockwell Collins SAASM includes:

NightHawk 12-channel GPS signal processor
Navigation using up to 12 GPS satellites
Advanced correlator engine for accelerated Direct-Y code and C/A code acquisitions
Security architecture using a Key Data Processor (KDP-II)
Unclassified-when-keyed operation and updated security features
The DAGR’s dual frequency RF front end allows continuous track of both the L1/L2 GPS satellite frequencies. A precision time source runs continuously to allow rapid acquisition of the GPS satellites when the receiver is turned on.

http://www.defenseindustrydaily.com/Rockwell-Collins-to-Deliver-DAGR-GPS-Receivers-to-US-Air-Force-05671/<\/u><\/a>

 Отправлено: 16.12.10 16:07. Заголовок: 2500 $ za woennij GP..

1600 $ za woennij GPS priemnik dlja Air Force 81 000 stuk

specifikazija

http://www.rockwellcollins.com/ecat/gs/dagr.html<\/u><\/a>

Extended performance in a diverse jamming environment.
41 dB J/S maintaining state 5 tracking.
24 dB during initial C/A code acquisition.


srawni s razrabotkoj nu force

http://www.nu-trek.com/nu-trek/rf-applications.html<\/u><\/a>

RF ASIC will support GPS tracking with 120 dB J/S.
###################################

Government sponsors have included the:

Missile Defense Agency (MDA)
U.S. Air Force
Department of Energy (DOE)
Defense Threat Reduction Agency (DTRA)
Defense Advanced Research Projects Agency (DARPA)
U.S. Navy
National Aeronautics and Space Administration (NASA)
Key industrial partners included:

Raytheon
Ball Aerospace
Honeywell
SAIC
Other Prime and 2nd Tier Defense Contractors

 Отправлено: 16.12.10 17:07. Заголовок: http://www.insidegns..

 Отправлено: 16.12.10 18:31. Заголовок: The nominal minimum ..

The nominal minimum GPS receiver base bandwidth of 50 Hz has been used for purposes
of calculating noise and jamming interference power levels so far in this series. This
approach was initially adopted for conceptual simplicity. But by this point, the reader is
aware that different GPS functions employ varying bandwidth processes.
################################################
Sometimes even
the same function employs variable adaptive bandwidth filtering techniques, as in the case
of the carrier/code tracking loops. To avoid the necessity of computing separate interference
levels for the multiple bandwidths employed in GPS receivers, it is common to reference
such computations to a 1 Hz bandwidth
#########################

http://wstiac.alionscience.com/pdf/Vol3Num4.pdf<\/u><\/a>

 Отправлено: 16.12.10 19:02. Заголовок: Lans -Добрый вечер..

Lans -Добрый вечер.
Есть ли возможность получить компетентный ответ (хотя бы в общем) от специалиста в области РЭБ?
Собственно интересует, возможно ли на нынешнем этапе эффективное подавление военных GPS приемников? С одной стороны подобные разработки есть и рекламируются, но "спецы" работающие с GPS говорят, что заявленные для таких систем дальность подавления в 100-150 км реальны только для гражданских изделий и для военных приемников эти значения будут составлять не более 150-200 метров. То есть, по факту, против ВТО с системами спутниковой коррекцией не эффективны
#############################################

srawnite 4 sluschaja w stat'e nize . Wo wsex sluschajx moschnost YM post. pomex 10 watt ( Rossisjkie w Irake -4 watta)

posmotrite kak powischaetsja j/S i snizaetsja radius dejstwija za schet suzenija polosi s 20 herz do 2 herz pri tracking ( 10 db)
za schet adaptive atenna patern (+26 db) i kombinazii

priwedena dalnost kak dlja aquisition tak i tracking dlja wsex sluchaew
-----------------------------------------------------------------------------------

woennie GPS priemniki 2002 goda

http://wstiac.alionscience.com/pdf/Vol3Num4.pdf<\/u><\/a>

dlja nowix razrabotokk tipa 120 db J/S ,sputnika s napr. antennoj(+20 db) ,M-code

potr. YM = 200 kwt srednej ( 2.4*2.4*3.6 metra ) ,Antenna na 1225 mgz 3.7 metra s Ky 31 db

Wse wmeste s generatorom pitanija wpolne mozno ystanowit na KAMAZ

Lampi dlja 200 kwt sredenej est bolee 40 let

 Отправлено: 27.03.11 00:14. Заголовок: o GPS/GLONASS i d..

o GPS/GLONASS i drugix sistemax navigazii

http://vko.forum24.ru/?1-3-40-00000178-000-0-0-1298455968

 Отправлено: 11.04.11 13:54. Заголовок: High-altitude nuclea..

High-altitude nuclear explosions

by Wm. Robert Johnston
last updated 28 January 2009

Effects of high-altitude nuclear explosions, summary:

The familiar immediate effects of low-altitude nuclear explosions are flash, blast, and prompt radiation. Effects are significantly different for explosions above most of the atmosphere. Since blast is the shock wave transmitted through air, this is attenuated with height and is absent for explosions beyond the atmosphere. Flash is the visible and infrared light pulse from the fireball formed from heated air. With higher altitude, the fireball formation is significantly altered with consequent effects on flash. Prompt radiation includes ionizing radiation from the nuclear reactions in the warhead and decay of fission products left by the explosion. These radiations, particularly neutron radiation, are significantly attenuated by the atmosphere for low altitude bursts. For explosions above most of the atmosphere, ranges of prompt radiation effects are greater than for atmospheric bursts.

Several effects are relatively unique to high altitude bursts:

* Electromagnetic pulse (EMP) is important only for high altitude bursts. For such detonations, ionization of the upper atmosphere can produce a brief intense pulse of radio frequency radiation which can damage or disrupt electronic devices. For explosions above most of the atmosphere, EMP can affect large areas.
* Ionization of the atmosphere from explosions in the atmosphere can interfere with radar and radio communications for short periods.
* Charged particles produced by explosions above the Earth's atmosphere can be captured by the Earth's magnetic field, temporarily creating artificial radiation belts that can damage spacecraft and injure astronauts/cosmonauts in orbit.

http://www.johnstonsarchive.net/nuclear/hane.html

 Отправлено: 11.04.11 20:51. Заголовок: 0800067 - High-Altit..

0800067 - High-Altitude Nuclear Weapon Effects Part Two - Systems Interference - 1963 - 16:29 - Color - Through past nuclear testing, the Department of Defense and the Atomic Energy Commission determined that a nuclear weapon exploded at high altitude with a sufficient yield would cause adverse effects on communication and radar devices.

This technically oriented video, which uses many animated audio-visual aids to explain scientific points of interest and explores the weapons effects on military systems. The first portion deals with a hypothetical reentry vehicle armed with a nuclear warhead. The video explains how three different nuclear detonations might be required to track and destroy the incoming vehicle. The next portion explains how a nuclear explosion would more adversely affect the low-power downlink of radio transmissions to aircraft or satellites than the more powerful uplink. Other atmospheric chemistry and infrared systems problems are discussed in the video.
[BR]http://www.youtube.com/watch?v=T6eLPLR_WPs


0800066 - High-Altitude Nuclear Weapon Effects Part One - Phenomenology - 1963 - 20:53 - Color - When nuclear weapons are detonated at high altitudes, they cause dramatic changes in the atmosphere and ionosphere. In a very technical presentation, this video discusses such things as the interactions of electrons and positive ions and shows the electromagnetic regions and how they carry electrical charges from one hemisphere to another. The video also discusses how there is much information unknown about nuclear explosions at extremely high altitudes, especially above 250 kilometers, where there is less atmospheric resistance.

http://www.youtube.com/watch?v=tdrirktDT2Y&feature=related

 Отправлено: 25.04.11 21:41. Заголовок: he Magnavox MX-8000 ..

he Magnavox MX-8000 Anti-jam GPS Receiver (AGR) was specifically designed for operation in heavily jammed environments, and was to be used in the cancelled Northrop AGM-137 TSSAM missile. This receiver uses adaptive nulling techniques to suppress jammers, and beam steering to boost the satellite signal. The receiver will acquire a GPS signal with a 70 dB Jam/Signal ratio (jam power 10,000,000 times higher than GPS signal) and once acquired, track a GPS signal with a 100 dB Jam/Signal ratio (jam power 10,000,000,000 times higher than GPS signal).
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Nowaja razrabotka do 120 db J/S ,no klipping w rajone 0 dbm ili xuze
0 dbm na 50ohm eto .224 volta

Dla srawnenija elektrostat. ysilitel priemnika S-300v rabotaet pri 150 voltax na wxode

ARU mozet oslabit 150 volt pomexi na wxode GPS priemnika do 0.1 volta ili mensche ,no
############################################################
poleznij signal toze budet oslablen
#########################

Prinimat odnowremmeno slabij signal GPS i ochen silnij pomexi GPS priemnik ne mozet

elektrostat . ysilitel ot S-300 V mozet / dlja atomnoj wojni/
It is worth comparing the complexity of this receiver with the simplicity of commercial receivers, which are highly susceptible to interference and hostile jamming (Hughes-Magnavox).
http://www.ausairpower.net/TE-GPS-Guided-Weps.html

 Отправлено: 30.04.11 12:13. Заголовок: 9S32 RLS The low n..

9S32 RLS

The low noise receiver (noise factor 3 dB) uses an electrostatic amplifier tube that can withstand leakage powers of several hundred Watts without damage and with near-instantaneous recovery to full gain and sensitivity when the transmitted pulse ends.
*****************************************************************************

7volt na 50 omnuju antennu eto 1 watt na wxode priemnika
70 volt eto 100 watt
[BR]http://www.ausairpower.net/APA-Russian-SAM-Radars-DKB.html#mozTocId551440
Thus, the loss attributed to solid-state protective devices commonly required in Western radars is also absent.



Dlja sravnenija s priemnikom S-300V ,kotorij rabotaet ,kogda na wxode bolee 100 volt -
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Nize na linke sxema woennogo GPS priemnika ,kotorij rabotosposben pre prewischenii pomexi nad signalom
na 120 db
##########
http://nu-trek.com/nu-trek/rf-applications.html/#RF%20receiver


... no clipping nastupaet pri 0 dbm ili daze mensche

0 dbm = 0.224 volta

 Отправлено: 02.06.11 19:14. Заголовок: The ambient temperat..

The ambient temperature and equipment noise factors are dominant and a typical effective noise temperature for a GPS receiver is 513 K

http://www.scribd.com/doc/23267811/GPS-Receiver-Architectures-and-Measurements

dlja sprawki y Cassegr, antenn w diapazone X schum.temperatura 40° K
Y maloschum neoxl. ysilitelja GaAS -60 ° k

y GPS priemnikow polosa ssuzaetsja do 1 herza ,chustw -163 dbm
teoreticheskij dlja polosi 1 herz -174 dbm/herz pri komnatnoj 293 grad

-174 dbm +10 log( schum temp antenni + schum.temp priemnika /293)
-174dbm + 10 log((60+40)/273)
-174dbm +10 *(0.436)
-174dbm-4.36 dbm = -178.36 dbm dlja polosi 1 herz
-148.36 dbm dlja polosi 1000 herz
-118.36 dlja polosi 1 megaherz

0 dbm = 0.224 volta na antennu 50 ohm

Snizenie schumowoj temperaturi primenika s pomoschju kriogennogo oxlazdenija
effektivno rawnozanchno ywleicheniju dimetru antenni w 1.5 -2 raza
( s 10 metrow do 15 -20 metrow )

Pri nawedeniee antenni na Solznce schumowaja temperatura powischaetsja
do 6000° K