Sat, 26 Jul 2008 06:04:53 BST CiteULike: dcastro's gps http://www.citeulike.org/user/dcastro/tag/gps CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dcastro/article/3039304 <i>GPS Solutions, Vol. 6, No. 3. (24 December 2002), pp. 179-195.</i><br /><br />Abstract.   The use of GPS for personal location using wireless devices requires satellite signal measurements both outdoors and indoors. In the outdoor environment propagation paths may range from line-of-sight to shaded or blocked. The indoor environment may range from single-floor wooden constructions to high-rise buildings and underground facilities. In this paper, a high-sensitivity receiver which operates in unaided stand-alone mode is tested under a range of shaded and blocked signal environments, ranging from residential outdoor areas to urban canyons and residential houses. The measurement analysis is performed in both the observation and position domains. The results show that the receiver tested is able to yield measurements with C/N0 degradations in excess of 20 dB-Hz, as compared to line-of-sight measurements. Position results are a function of the geometry of the remaining satellites, which in turn is a function of the environment. Performance analysis of a stand-alone high-sensitivity receiver Macgougan G Macgougan Lachapelle G Lachapelle Klukas R Klukas Siu K Siu Garin L Garin Shewfelt J Shewfelt Cox G Cox doi:10.1007/s10291-002-0029-z GPS Solutions, Vol. 6, No. 3. (24 December 2002), pp. 179-195. 2008-07-24T11:47:54-00:00 2002 GPS Solutions 6 3 179 195 galileo gnss gps performance receiver http://www.citeulike.org/user/dcastro/article/3037968 <i>Aerospace and Electronic Systems, IEEE Transactions on, Vol. 32, No. 2. (1996), pp. 754-767.</i><br /><br />The accuracy analysis of Global Positioning System (GPS) carrier phase observable measured by a digital GPS receiver is presented. A digital phase-locked loop (DPLL) is modeled to extract the carrier phase of the received signal after a pseudorandom noise (PRN) code synchronization system despreads the received PRN coded signal. Based on phase noise characteristics of the input signal, the following performance of the first, second, and third-order DPLLs is analyzed mathematically: (1) loop stability and transient process; (2) steady-state probability density function (pdf), mean and variance of phase tracking error; (3) carrier phase acquisition performance; and (4) mean time to the first cycle-slipping. The theoretical analysis is verified by Monte Carlo computer simulations. The analysis of the dependency of the phase input noise and receiver design parameters provides with an important reference in designing the carrier phase synchronization system for high accuracy GPS positioning Performance analysis of GPS carrier phase observable W Zhuang doi:10.1109/7.489518 Aerospace and Electronic Systems, IEEE Transactions on, Vol. 32, No. 2. (1996), pp. 754-767. 2008-07-23T23:54:13-00:00 1996 Aerospace and Electronic Systems, IEEE Transactions on 32 2 754 767 carrier gps phase http://www.citeulike.org/user/dcastro/article/3036739 <i>Signal Processing, IEEE Transactions on, Vol. 50, No. 1. (2002), pp. 141-150.</i><br /><br />We address the problem of GPS signal delay estimation in a multipath environment with a low-complexity constraint. After recalling the usual early-late estimator and its bias in a multipath propagation context, we study the maximum-likelihood estimator (MLE) based on a signal model including the parametric contribution of reflected components. It results in an efficient algorithm using the existing architecture, which is also very simple and cheap to implement. Simulations show that the results of the proposed algorithm, in a multipath environment, are similar to these of the early-late in a single-path environment. The performance are further characterized, for both MLEs (based on the single-path and multipath propagation) in terms of bias and standard deviation. The expressions of the corresponding Cramer-Rao (CR) bounds are derived in both cases to show the good performance of the estimators when unbiased GPS positioning in a multipath environment J Soubielle I Fijalkow P Duvaut A Bibaut doi:10.1109/78.972490 Signal Processing, IEEE Transactions on, Vol. 50, No. 1. (2002), pp. 141-150. 2008-07-23T11:52:15-00:00 2002 Signal Processing, IEEE Transactions on 50 1 141 150 gps multipath positioning http://www.citeulike.org/user/dcastro/article/3021116 <i>Antennas and Propagation Society International Symposium, 1993. AP-S. Digest (1993), pp. 1478-1481 vol.3.</i><br /><br />The authors describe the preliminary designs of two different types of microstrip antennas, i.e., those providing dual-frequency circularly-polarized (CP) operation; and enhanced low-angle radiation. The first type of antennas was designed to operate at the GPS (Global Positioning System) frequencies of 1.227 and 1.575 GHz, and was fabricated by using a novel combination of recessed cavity and patch type of resonators. For the second type of antenna, achieving enhanced gain at lower angles without sacrificing the CP performance turned out to be a difficult challenge. After many unsuccessful attempts, a preliminary design that employed a pyramidal configuration appeared to exhibit good promise and favorable potential for further improvement Microstrip patch antennas for GPS applications R Mittra R Yang M Itoh M Arakawa doi:10.1109/APS.1993.385474 Antennas and Propagation Society International Symposium, 1993. AP-S. Digest (1993), pp. 1478-1481 vol.3. 2008-07-19T17:10:57-00:00 1993 Antennas and Propagation Society International Symposium, 1993. AP-S. Digest 1478 1481 vol.3 antenna application gps microstrip patch http://www.citeulike.org/user/dcastro/article/3021108 <i>Antennas and Propagation, IEEE Transactions on, Vol. 53, No. 3. (2005), pp. 1227-1229.</i><br /><br />This communication presents a novel design of a compact microstrip antenna practical for both the global positioning system (GPS) and digital communication system (DCS). The proposed antenna consists of two parts: a fundamental mode truncated square patch antenna and a higher-order mode annular ring patch antenna. The truncated square patch operated in right-hand circular polarization at 1575 MHz with 8-MHz CP bandwidth, making the design suitable for the GPS. Further, four slots were embedded into a ground plane to meander the current path of the annular ring patch at the TM/sub 21/ mode, which considerably lowered the resonant frequency and effectively increased the impedance bandwidth. These features reduce the antenna size and make the design appropriate for DCS. Both radiators are placed in a common space but operate independently. The experimental results show that this design is ideally suited for GPS/DCS dual-band mobile communications. A compact microstrip antenna for GPS and DCS application Shun-Yun Lin Kuang-Chih Huang doi:10.1109/TAP.2004.842597 Antennas and Propagation, IEEE Transactions on, Vol. 53, No. 3. (2005), pp. 1227-1229. 2008-07-19T17:04:18-00:00 2005 Antennas and Propagation, IEEE Transactions on 53 3 1227 1229 compact gps microstrip mobile http://www.citeulike.org/user/dcastro/article/2988892 <i>Antennas and Propagation International Symposium, 2007 IEEE (2007), pp. 3784-3787.</i><br /><br />A new approach to developing miniaturized GPS antennas suitable for use in CRPA anti-jam arrays is presented. The approach leverages recent advances in fragmented aperture antenna design and manufacturing. This approach uses a combination of FDTD simulations combined with genetic optimization. Fragmented aperture antenna design of miniaturized GPS CRPA: model and measurements JG Maloney BN Baker JJ Acree JW Schultz JA Little DD Reuster doi:10.1109/APS.2007.4396363 Antennas and Propagation International Symposium, 2007 IEEE (2007), pp. 3784-3787. 2008-07-11T15:19:01-00:00 2007 Antennas and Propagation International Symposium, 2007 IEEE 3784 3787 antenna gps http://www.citeulike.org/user/dcastro/article/2988894 <i>Ultra Wideband Systems and Technologies, 2002. Digest of Papers. 2002 IEEE Conference on (2002), pp. 123-127.</i><br /><br />We compare the positioning performance of GPS and DGPS to that of GPS/DGPS integrated with non-interfering UWB transponders. Simulations of a simple test case predict 15% horizontal accuracy improvement of GPS+UWB over stand-alone GPS and 25% improvement of DGPS+UWB over pure DGPS. Integrated GPS and UWB navigation system: (motivates the necessity of non-interference) GR Opshaug P Enge doi:10.1109/UWBST.2002.1006332 Ultra Wideband Systems and Technologies, 2002. Digest of Papers. 2002 IEEE Conference on (2002), pp. 123-127. 2008-07-11T15:19:08-00:00 2002 Ultra Wideband Systems and Technologies, 2002. Digest of Papers. 2002 IEEE Conference on 123 127 gps interference navigation uwb http://www.citeulike.org/user/dcastro/article/2896211 <i>Communication Technology, 2006. ICCT '06. International Conference on (2006), pp. 1-4.</i><br /><br />This paper is a brief study of the Global Positioning System (GPS) P-code acquisition based on FFT. P-code has a higher chipping rate, better accuracy and anti-jamming property than C/A code. When C/A code is not available, direct P-code acquisition is useful. In this paper, the implementation on FPGA and DSP board proves that the technique using FFT (Fast Fourier Transform) has greatly reduced the acquisition times and calculations. Direct P-code Acquisition Based on FFT Lian Baowang Cao Na doi:10.1109/ICCT.2006.341999 Communication Technology, 2006. ICCT '06. International Conference on (2006), pp. 1-4. 2008-06-15T13:46:35-00:00 2006 Communication Technology, 2006. ICCT '06. International Conference on 1 4 acquisition fft gps http://www.citeulike.org/user/dcastro/article/2890778 <i>GPS Solutions, Vol. 7, No. 3. (1 December 2003), pp. 168-175.</i><br /><br />GPS P-Code has a higher chipping rate, better accuracy, and anti-jamming property than C/A code. Traditionally, GPS P-Code acquisition depends on handover from C/A code. This potentially needs long acquisition time. Moreover, when C/A code is not available, it is no longer possible to acquire GPS P-Code through handover from C/A code. The purpose of this paper is to describe a new overlap average method to facilitate hardware design of fast direct P-Code acquisition. It allows the rapid code phase search to acquire GPS P-Code signals, and also decreases the hardware resource requirement. The small size FFT in the proposed methods is very promising for fast FPGA hardware system design using FFT cores. The simulation results and theoretical analysis are included demonstrating the overall performance of the proposed method. Fast direct GPS P-Code acquisition Jing Pang Frankvan Graas Janusz Starzyk Zhen Zhu doi:10.1007/s10291-003-0070-6 GPS Solutions, Vol. 7, No. 3. (1 December 2003), pp. 168-175. 2008-06-13T08:37:37-00:00 2003 GPS Solutions 7 3 168 175 acquisition code gps http://www.citeulike.org/user/dcastro/article/2877936 <i>Aerospace and Electronic Systems, IEEE Transactions on, Vol. 31, No. 2. (1995), pp. 739-751.</i><br /><br />In this paper, a digital system for the Global Positioning System (GPS) pseudo-range observable is modeled and analyzed theoretically. The observable is measured in a GPS receiver by accurately tracking the pseudorandom noise (PRN) code phase of the input GPS signal using a digital energy detector and a digital delay lock loop (DDLL). The following issues are presented: (1) mathematical modeling of the digital PRN code acquisition and tracking system, (2) the closed-form expression derivation for the detection and false-alarm probabilities of the acquisition process and for the variance of code phase tracking error, and (3) the linear and nonlinear performance analysis of the DDLL for optimizing the receiver structures and parameters with tradeoff between the tracking errors due to receiver dynamics and due to input noise Modeling and analysis for the GPS pseudo-range observable Weihua Zhuang J Tranquilla doi:10.1109/7.381921 Aerospace and Electronic Systems, IEEE Transactions on, Vol. 31, No. 2. (1995), pp. 739-751. 2008-06-09T19:24:45-00:00 1995 Aerospace and Electronic Systems, IEEE Transactions on 31 2 739 751 analysis gps http://www.citeulike.org/user/dcastro/article/2859759 <i>Position, Location, And Navigation Symposium, 2006 IEEE/ION (2006), pp. 483-493.</i> Code-Carrier Divergence Monitoring for the GPS Local Area Augmentation System DV Simili B Pervan Position, Location, And Navigation Symposium, 2006 IEEE/ION (2006), pp. 483-493. 2008-06-03T18:58:57-00:00 2006 Position, Location, And Navigation Symposium, 2006 IEEE/ION 483 493 carrier code gps integrity http://www.citeulike.org/user/dcastro/article/2814009 <i>Signal Processing, IEEE Transactions on [see also Acoustics, Speech, and Signal Processing, IEEE Transactions on], Vol. 56, No. 3. (2008), pp. 990-1004.</i><br /><br /><para> Global positioning system (GPS) receivers find growing applications in indoor and outdoor communication environments, including urban and rural areas. Interference and noise sources for GPS receivers may assume Gaussian or non-Gaussian distributions. The GPS receiver performance under Gaussian additive noise has been studied. Non-Gaussian noise may equally contaminate the GPS satellite signals and disturb the receiver delay lock loops (DLL), producing significant tracking errors. These sources include impulsive noise, ultra-wideband (UWB) signals, and impulse and noise radar signals for target tracking and indoor imaging applications. This paper considers non-Gaussian noise of finite variance and examines its effect on the discriminator outputs for the commercial GPS receiver that uses the coarse acquisition (C/A) code. The correlator noise output components are produced from the correlation between the noise sequence and the early, late, and punctual reference C/A code. Due to the long time averaging, which is characteristic of the GPS correlation loops, these components assume Gaussian distributions. The discriminator tracking error variance is derived, incorporating the effect of noise, the front-end precorrelation filter, and the sampling rate. </para> Performance Analysis of GPS Receivers in Non-Gaussian Noise Incorporating Precorrelation Filter and Sampling Rate L Liu MG Amin doi:10.1109/TSP.2006.890827 Signal Processing, IEEE Transactions on [see also Acoustics, Speech, and Signal Processing, IEEE Transactions on], Vol. 56, No. 3. (2008), pp. 990-1004. 2008-05-19T19:45:47-00:00 2008 Signal Processing, IEEE Transactions on [see also Acoustics, Speech, and Signal Processing, IEEE Transactions on] 56 3 990 1004 filter gps noise performance receiver http://www.citeulike.org/user/dcastro/article/2813984 <i>ION GPS/GNSS 2003 (2003)</i> Optimal GPS-Tracking Even in Case of Line-of-Sight Loss Karl Kaindl Norbert Niklasch ION GPS/GNSS 2003 (2003) 2008-05-19T19:30:24-00:00 2003 ION GPS/GNSS 2003 gps tracking http://www.citeulike.org/user/dcastro/article/2813900 <i></i> A High Bandwidth GPS L1/L2 C/A Code Software Receiver For Real Time Kinematic Positioning Thomas Pany Frank Förster Daniel Sanroma Bernd Eissfeller 2008-05-19T18:51:49-00:00 gps receiver software http://www.citeulike.org/user/dcastro/article/2809073 <i>Position Location and Navigation Symposium, 1996., IEEE 1996 (1996), pp. 604-611.</i><br /><br />GPS receivers must perform a two-dimensional sequential search process for the GPS signals. The two-dimensional search pattern consists of discrete search cells with each cell representing one code bin and one carrier Doppler bin. The code bin width is usually ½-half chip. The longer the dwell time per binary decision (the predetection integration time), the narrower the Doppler bin width and weaker GPS signals can be acquired, but the search time increases. The replica C/A-code generates larger than normal sidelobes if the Doppler bin is too wide (when predetection integration time is too short), False acquisition of the sidelobes can occur if the search threshold is set too low. At the heart of the receiver search process is the search detector. There are significant performance differences between search detector algorithms. This paper describes, analyzes and compares two powerful sequential search algorithms: the fixed-dwell-time M-of-N detector and the variable dwell time Tong detector (1973) GPS receiver search techniques PW Ward doi:10.1109/PLANS.1996.509134 Position Location and Navigation Symposium, 1996., IEEE 1996 (1996), pp. 604-611. 2008-05-18T14:07:47-00:00 1996 Position Location and Navigation Symposium, 1996., IEEE 1996 604 611 acquisition gps receiver http://www.citeulike.org/user/dcastro/article/2808943 <i>Proc. Institute of Navigation GPS 2003 (2003)</i> The Acquisition Process of a Maximum Likelihood GPS Receiver Progri Proc. Institute of Navigation GPS 2003 (2003) 2008-05-18T12:45:37-00:00 2003 Proc. Institute of Navigation GPS 2003 acquisition gps ml receiver http://www.citeulike.org/user/dcastro/article/2808925 <i>ION NTM 2007 Proceedings (2007)</i> A Theoretical Survey of the Spreading Modulation of the New GPS Signals (L1C, L2C, and L5) IF Progri WR Michalson J Wang ION NTM 2007 Proceedings (2007) 2008-05-18T12:33:34-00:00 2007 ION NTM 2007 Proceedings galileo gps modulation http://www.citeulike.org/user/dcastro/article/2776228 <i>Antennas and Wireless Propagation Letters, IEEE, Vol. 2 (2003), pp. 6-8.</i><br /><br />An L1 Global Positioning System (GPS) antenna with improved multipath-rejection capability is presented. The antenna is realized with a shorted annular elliptical patch (SAEP). Some of the characteristics of SAEP are presented briefly and a detailed account of the design is given. Measured results are presented and discussed. A shorted elliptical patch antenna for GPS applications L Boccia G Amendola G Di Massa doi:10.1109/LAWP.2003.810767 Antennas and Wireless Propagation Letters, IEEE, Vol. 2 (2003), pp. 6-8. 2008-05-09T16:10:39-00:00 2003 Antennas and Wireless Propagation Letters, IEEE 2 6 8 antenna gps patch shorted http://www.citeulike.org/user/dcastro/article/2768908 <i>36th Annual Symposium on Frequency Control. 1982 (1982), pp. 378-387.</i> Optimal Time and Frequency Transfer Using GPS Signals DW Allan JA Barnes 36th Annual Symposium on Frequency Control. 1982 (1982), pp. 378-387. 2008-05-08T07:59:06-00:00 1982 36th Annual Symposium on Frequency Control. 1982 378 387 frequency gps time http://www.citeulike.org/user/dcastro/article/2764015 <i>Electronics Letters, Vol. 28, No. 9. (1992), pp. 863-865.</i><br /><br />A novel `differential' decoding technique is proposed which enables pre-averaging instead of postintegration for a substantially low update rate `FFT-IFT' correlation in spread-spectrum (navigational) receivers. <e1>N</e1>-channel code acquisition can be performed to monitor the time dispersion with FFT time left to analyse frequency dispersion in highly reflective areas (e.g. an urban environment) Novel fast GPS/GLONASS code-acquisition technique using low update rate FFT AJRM Coenen DJR Van Nee Electronics Letters, Vol. 28, No. 9. (1992), pp. 863-865. 2008-05-07T06:45:02-00:00 1992 Electronics Letters 28 9 863 865 acquisition code fast fft gnss gps http://www.citeulike.org/user/dcastro/article/2764003 <i>Electronics Letters, Vol. 27, No. 2. (1991), pp. 158-160.</i><br /><br />A new spread-spectrum code-acquisition technique for the navigation systems Navstar/GPS and Glonass is introduced. This technique uses the FFT to compute the correlation function, thereby eliminating the time-consuming code phase shift process. Comparisons with existing systems show a theoretical reduction in acquisition time of about 2000 times New Fast GPS code-acquisition technique using FFT DJR Van Nee AJRM Coenen Electronics Letters, Vol. 27, No. 2. (1991), pp. 158-160. 2008-05-07T06:42:16-00:00 1991 Electronics Letters 27 2 158 160 acquisition code fast fft gps http://www.citeulike.org/user/dcastro/article/2763950 <i>Circuits and Systems, 2003. ISCAS '03. Proceedings of the 2003 International Symposium on, Vol. 4 (2003), pp. IV-500-IV-503 vol.4.</i><br /><br />Current GPS receivers spend much time in base-band processing, performing acquisition and tracking. This is due to the large number of required operations in the software-based signal processing. This paper presents a novel signal acquisition and tracking method that reduces the number of operations, simplifies hardware implementation and decreases the acquisition time. The implementation of this method in an FPGA provides very fast processing of incoming GPS samples that satisfies real-time requirements. Real-time acquisition and tracking for GPS receivers A Alaqeeli J Starzyk F van Graas doi:10.1109/ISCAS.2003.1205933 Circuits and Systems, 2003. ISCAS '03. Proceedings of the 2003 International Symposium on, Vol. 4 (2003), pp. IV-500-IV-503 vol.4. 2008-05-07T06:24:49-00:00 2003 Circuits and Systems, 2003. ISCAS '03. Proceedings of the 2003 International Symposium on 4 IV-500 IV-503 vol.4 acquisition gps receiver tracking http://www.citeulike.org/user/dcastro/article/2763869 <i>Microwave Theory and Techniques, IEEE Transactions on, Vol. 53, No. 10. (2005), pp. 3082-3089.</i><br /><br />The use of direct RF sampling has been explored as a means of designing multifrequency RF front ends. Such front ends will be useful to multifrequency RF applications such as global navigation satellite system receivers that use global positioning system (GPS) L1, L2, and L5 signals and Galileo signals. The design of a practical multifrequency direct RF sampling front end is dependent on having an analog-to-digital converter whose input bandwidth accommodates the highest carrier frequency and whose maximum sampling frequency is more than twice the cumulative bandwidth about the multiple carrier signals. The principle of direct RF sampling is used to alias all frequency bands of interest onto portions of the Nyquist bandwidth that do not overlap. This paper presents a new algorithm that finds the minimum sampling frequency that avoids overlap. This design approach requires a multifrequency bandpass filter for the frequency bands of interest. A prototype front end has been designed, built, and tested. It receives a GPS coarse/acquisition code at the L1 frequency and GPS antispoofing precision code at both L1 and L2. Dual-frequency signals with received carrier-to-noise ratios in excess of 52 dB-Hz have been acquired and tracked using this system. Design and practical implementation of multifrequency RF front ends using direct RF sampling ML Psiaki SP Powell Hee Jung PM Kintner doi:10.1109/TMTT.2005.855127 Microwave Theory and Techniques, IEEE Transactions on, Vol. 53, No. 10. (2005), pp. 3082-3089. 2008-05-07T06:08:30-00:00 2005 Microwave Theory and Techniques, IEEE Transactions on 53 10 3082 3089 design frequency front-end galileo gnss gps multi rf sampling http://www.citeulike.org/user/dcastro/article/2674648 <i>Position Location and Navigation Symposium, 2004. PLANS 2004 (2004), pp. 503-509.</i><br /><br />The global navigation satellite systems (GNSS) market is anticipated by most market researchers to experience exponential growth in the consumer segment, to the largest extend through the introduction of location based services (LBS). LBS - including the U.S. E-911 mandate - require position fixes at demanding rural sites, such as urban canyon, moderate indoor, and in vehicles without external antennae. The satellite signals are not only attenuated, but also subjected to strong multipath fading. Developing GPS/Galileo receivers for high-volume markets requires support for LBS, which in turn necessitates enhanced receiver sensitivity and multipath robustness. Which business cases are feasible is therefore partially determined by the maximally achievable sensitivity under various multipath scenarios. These sensitivity limits form a baseline for the receiver design. This paper algebraically derives the sensitivity limits for acquisition (i.e. synchronization) of direct sequence spread spectrum positioning signals under multipath propagation conditions. The derived formulas are then evaluated exemplarily for the parameters of the openly accessible L1-band GPS and Galileo signals, while they are also valid for other positioning signals. As commonly applied in wireless communications, the multipath environment is modelled with stochastic Ricean fading processes. The derived sensitivity limits are based on the stochastic models for multipath and noise, being transformed by RF-downconversion, despreading, coherent integration, envelope detection, noncoherent integration, and Neyman-Pearson detection. These results are also provided as plots of probability of detection versus carrier power to noise power spectral density, parameterized for various noncoherent integration times and Ricean factors. Comparison of the sensitivity limits for GPS and Galileo receivers in multipath scenarios A Schmid A Neubauer Position Location and Navigation Symposium, 2004. PLANS 2004 (2004), pp. 503-509. 2008-04-15T18:03:01-00:00 2004 Position Location and Navigation Symposium, 2004. PLANS 2004 503 509 galileo gps multipath receive http://www.citeulike.org/user/dcastro/article/2673363 <i>Proceedings of the IEEE, Vol. 87, No. 1. (1999), pp. 86-91.</i><br /><br />Multipath interference limits the speed and accuracy of determining position by differential Global Positioning System (DGPS) techniques. A geodetic surveyor for example, requires multipath interference rejection of about 36+20log₁₀sin&epsiv; dB, where &epsiv; is the elevation angle of the satellite being observed. Signal processing in a GPS receiver cannot satisfy this requirement. A receiving antenna is required that can sufficiently reject signals arriving from below the horizon. Available antennas have inadequate rejection, and brute-force methods of improving them, e.g., by enlarging their ground-planes, are impractical. A compact, ground-planeless, dual-band GPS antenna with improved multipath rejection has been designed and field-tested. This antenna resembles a vertical post rather than a horizontal platter; within its 0.1-m diameter, 0.4-m tall randome is a vertical array of turnstile elements. In field tests, a three-element array antenna rejected multipath better than a 0.5-m diameter ground-plane antenna by an average of 5 dB. A five-element array antenna appears superior to a 0.9-m diameter ground-plane antenna Multipath-rejecting GPS antennas Counselman doi:10.1109/5.736343 Proceedings of the IEEE, Vol. 87, No. 1. (1999), pp. 86-91. 2008-04-15T12:48:40-00:00 1999 Proceedings of the IEEE 87 1 86 91 antenna gps mitigation multipath http://www.citeulike.org/user/dcastro/article/2673345 <i>Aerospace and Electronic Systems, IEEE Transactions on, Vol. 37, No. 1. (2001), pp. 298-304.</i><br /><br />Spread-spectrum ranging multipath model validation results are presented. Previously published theoretical results are compared with data obtained from bench-testing using a multichannel satellite simulator. Results are presented for standard or wide-correlator (i.e., 1 chip early-to-late correlator spacing) and narrow-correlator (i.e., 0.1 chip) GPS C/A-code architectures as well as standard P-code. The close agreement of the bench data and theoretical results confirm the validity of the theoretical model Spread-spectrum ranging multipath model validation MS Braasch MF Dibenedetto doi:10.1109/7.913691 Aerospace and Electronic Systems, IEEE Transactions on, Vol. 37, No. 1. (2001), pp. 298-304. 2008-04-15T12:42:14-00:00 2001 Aerospace and Electronic Systems, IEEE Transactions on 37 1 298 304 gps model multipath range spread-spectrum http://www.citeulike.org/user/dcastro/article/2673343 <i>Aerospace and Electronic Systems, IEEE Transactions on, Vol. 33, No. 1. (1997), pp. 290-295.</i><br /><br />The effects of autocorrelation sidelobes on multipath errors in pseudorandom noise (PRN) ranging systems are investigated. It is shown that both medium-delay (i.e., on the order of 1 PRN chip) as well as long-delay multipath errors are affected. Results are applied to the case of the Global Positioning System (GPS). Autocorrelation sidelobe considerations in the characterization of multipath errors MS Braasch doi:10.1109/7.570787 Aerospace and Electronic Systems, IEEE Transactions on, Vol. 33, No. 1. (1997), pp. 290-295. 2008-04-15T12:41:18-00:00 1997 Aerospace and Electronic Systems, IEEE Transactions on 33 1 290 295 cdma correlation error gps multipath http://www.citeulike.org/user/dcastro/article/2673340 <i>Position Location and Navigation Symposium, 1996., IEEE 1996 (1996), pp. 672-678.</i><br /><br />Multipath represents the dominant error source in satellite-based precision guidance systems. Since multipath errors are not common to the reference station and remote receivers, they are not eliminated through differential corrections and they do not cancel out in a differential carrier-phase tracking system. For precision approach applications, multipath is the most significant obstacle to overcome in the quest for CAT III accuracy and integrity using code-DGPS. Although a multitude of GPS articles discuss the effects of multipath, few derive the basic relationships between the composite signal at the antenna and the resulting measurement error. Furthermore, no validation of the aforementioned theory has been performed to date. This paper presents a comprehensive treatment of the problem. The traditional theoretical multipath error relationships are presented along with validation results obtained from bench-testing using a multichannel satellite simulator. Results are presented for standard and narrow-correlator C/A-code architectures as well as standard P-code. One result of particular interest to the aviation community is validation of the theoretical results which indicate that airframe-based multipath error cannot be reduced with narrow-correlator or P-code technology GPS multipath model validation MS Braasch doi:10.1109/PLANS.1996.509144 Position Location and Navigation Symposium, 1996., IEEE 1996 (1996), pp. 672-678. 2008-04-15T12:40:21-00:00 1996 Position Location and Navigation Symposium, 1996., IEEE 1996 672 678 gps model multipath http://www.citeulike.org/user/dcastro/article/1591767 <i>Personal Communications, IEEE [see also IEEE Wireless Communications], Vol. 7, No. 5. (2000), pp. 28-34.</i><br /><br />Instrumenting the physical world through large networks of wireless sensor nodes, particularly for applications like environmental monitoring of water and soil, requires that these nodes be very small, lightweight, untethered, and unobtrusive. The problem of localization, that is, determining where a given node is physically located in a network, is a challenging one, and yet extremely crucial for many of these applications. Practical considerations such as the small size, form factor, cost and power constraints of nodes preclude the reliance on GPS of all nodes in these networks. We review localization techniques and evaluate the effectiveness of a very simple connectivity metric method for localization in outdoor environments that makes use of the inherent RF communications capabilities of these devices. A fixed number of reference points in the network with overlapping regions of coverage transmit periodic beacon signals. Nodes use a simple connectivity metric, which is more robust to environmental vagaries, to infer proximity to a given subset of these reference points. Nodes localize themselves to the centroid of their proximate reference points. The accuracy of localization is then dependent on the separation distance between two-adjacent reference points and the transmission range of these reference points. Initial experimental results show that the accuracy for 90 percent of our data points is within one-third of the separation distance. However, future work is needed to extend the technique to more cluttered environments GPS-less low-cost outdoor localization for very small devices N Bulusu J Heidemann D Estrin doi:10.1109/98.878533 Personal Communications, IEEE [see also IEEE Wireless Communications], Vol. 7, No. 5. (2000), pp. 28-34. 2007-08-25T07:37:52-00:00 2000 Personal Communications, IEEE [see also IEEE Wireless Communications] 7 5 28 34 gps location low outdoor small http://www.citeulike.org/user/dcastro/article/2410366 <i>EURASIP J. Appl. Signal Process., Vol. 2006, No. 1. (January uary), pp. 157-157.</i> Feedforward delay estimators in adverse multipath propagation for Galileo and modernized GPS signals Elena Lohan Abdelmonaem Lakhzouri Markku Renfors doi:10.1155/ASP/2006/50971 EURASIP J. Appl. Signal Process., Vol. 2006, No. 1. (January uary), pp. 157-157. 2008-02-22T07:32:24-00:00 EURASIP J. Appl. Signal Process. 1110-8657 2006 1 157 157 Hindawi Publishing Corp. delay estimation feedforward galileo gps multipath propagation http://www.citeulike.org/user/dcastro/article/2408017 <i>Multimedia Signal Processing and Communications, 48th International Symposium ELMAR-2006 focused on (2006), pp. 215-217.</i><br /><br />Ionospheric errors are the most influential source of the GPS positioning errors. In an attempt to at least partially improve the GPS positioning process, a global ionospheric correction model is introduced within the standard GPS positioning service. Referred to as the Klobuchar model after its inventor, this model appeared as a compromise between computation complexity and correction accuracy. Unfortunately, the Klobuchar model is capable of correcting up to 70% of ionospheric errors, with particularly poor performance during severe ionospheric disturbances. Wide implementations of satellite navigation systems (GPS in particular) in modern technical systems call for better corrections of the ionospheric influence. This article presents three essential approaches in modelling the GPS ionospheric errors (physical, empirical and dynamic models) and discusses their implementation in GPS-based technical systems GPS Ionospheric Error Correction Models R Filjar T Kos I Markezic doi:10.1109/ELMAR.2006.329552 Multimedia Signal Processing and Communications, 48th International Symposium ELMAR-2006 focused on (2006), pp. 215-217. 2008-02-21T15:49:54-00:00 2006 Multimedia Signal Processing and Communications, 48th International Symposium ELMAR-2006 focused on 215 217 correction error gps ionospheric model http://www.citeulike.org/user/dcastro/article/2362131 <i>Proceedings of the IEEE, Vol. 87, No. 1. (1999), pp. 48-64.</i><br /><br />Although originally developed for the military, the Global Positioning System (GPS) has proven invaluable for a multitude of civilian applications. Each application demands specific performance from the GPS receiver and the associated requirements often vary widely. This paper describes the architectures and functions of civilian GPS receivers and then focuses on performance considerations. The fundamental receiver measurements are described and the quality of these measurements are related to the aforementioned receiver architectures GPS receiver architectures and measurements MS Braasch AJ van Dierendonck doi:10.1109/5.736341 Proceedings of the IEEE, Vol. 87, No. 1. (1999), pp. 48-64. 2008-02-11T09:58:35-00:00 1999 Proceedings of the IEEE 87 1 48 64 delay dll gnss gps loop measurement receiver http://www.citeulike.org/user/dcastro/article/2362087 <i>Vehicular Technology Conference, 2002. Proceedings. VTC 2002-Fall. 2002 IEEE 56th, Vol. 3 (2002), pp. 1602-1606 vol.3.</i><br /><br />The location requirements for emergency callers outside urban areas can hardly be fulfilled without Global Navigation Satellite Systems (GNSS). Consequently, interest in positioning techniques based on use of a GNSS such as GPS or on the cellular network infrastructure itself is growing rapidly in the mobile telephone community. The technical similarity based on the use of DS-CDMA spread-spectrum technology opens the door for the combination of GNSS with cellular network-based wireless location and positioning. The paper seeks to provide some initial answers to the question of whether mobile handset architecture synergies exist for the combination of GNSS with UMTS/cdma2000 cellular wireless networks. In this respect, we pay particular attention to the RAKE receiver architecture employed in mobile CDMA cellular handsets. Receiver architecture synergies between future GPS/Galileo and UMTS/IMT-2000 G Heinrichs R Bischoff T Hesse doi:10.1109/VETECF.2002.1040486 Vehicular Technology Conference, 2002. Proceedings. VTC 2002-Fall. 2002 IEEE 56th, Vol. 3 (2002), pp. 1602-1606 vol.3. 2008-02-11T09:41:27-00:00 2002 Vehicular Technology Conference, 2002. Proceedings. VTC 2002-Fall. 2002 IEEE 56th 3 1602 1606 vol.3 galileo gnss gps mobile receiver umts http://www.citeulike.org/user/dcastro/article/2355171 <i>Position, Location, And Navigation Symposium, 2006 IEEE/ION (2006), pp. 883-892.</i> MBOC: The New Optimized Spreading Modulation Recommended for GALILEO L1 OS and GPS L1C GW Hein JA Avila-Rodriguez S Wallner AR Pratt J Owen J Issler JW Betz CJ Hegarty S Lenahan S Lenahan JJ Rushanan A10 AL Kraay A11 TA Stansell A12 Position, Location, And Navigation Symposium, 2006 IEEE/ION (2006), pp. 883-892. 2008-02-08T23:57:44-00:00 2006 Position, Location, And Navigation Symposium, 2006 IEEE/ION 883 892 galileo gps mboc modulation http://www.citeulike.org/user/dcastro/article/2284888 <i>Antennas and Propagation, IEEE Transactions on, Vol. 38, No. 10. (1990), pp. 1545-1550.</i><br /><br />An analytic model for computing the radiation properties of the quadrifilar helix volute antenna is discussed and various design considerations for GPS applications are presented. The effects of modifying the antenna length and diameter on the antenna amplitude and phase performance are presented, and using the antenna for dual-frequency operation is discussed. The effects of phase imbalances are presented and compared with measured pattern anomalies A study of the quadrifilar helix antenna for Global Positioning System (GPS) applications JM Tranquilla SR Best doi:10.1109/8.59766 Antennas and Propagation, IEEE Transactions on, Vol. 38, No. 10. (1990), pp. 1545-1550. 2008-01-24T14:31:43-00:00 1990 Antennas and Propagation, IEEE Transactions on 38 10 1545 1550 antenna gps helix http://www.citeulike.org/user/dcastro/article/2187927 <i>Antennas and Propagation, IEEE Transactions on, Vol. 55, No. 8. (2007), pp. 2358-2366.</i><br /><br />A new Global Positioning System (GPS) microstrip patch antenna designed for dual-band (LI /L2) operation is introduced. The antenna design is based on the reduced-surface-wave (RSW) concept and, as a result, is much less susceptible to low-angle multipath interference effects than some of the more commonly-used high-precision GPS antennas. In this paper, the radiation characteristics of this new design was compared to a dual- band choke-ring and a dual-band pinwheel antenna. In addition to having the advantages typically associated with microstrip patch antennas, this planar dual-band antenna lacks the design complications associated with the frequently-used stacked-patch method for realizing dual-band microstrip antenna performance. Thus, the simplicity of the design, together with the reduced horizon and backside radiation levels and excellent circular polarization characteristics indicate that this new antenna design is a promising candidate for dual-band, high-precision applications. A New Planar Dual-Band GPS Antenna Designed for Reduced Susceptibility to Low-Angle Multipath LI Basilio RL Chen JT Williams DR Jackson doi:10.1109/TAP.2007.901818 Antennas and Propagation, IEEE Transactions on, Vol. 55, No. 8. (2007), pp. 2358-2366. 2008-01-02T12:17:22-00:00 2007 Antennas and Propagation, IEEE Transactions on 55 8 2358 2366 antenna dual-band gps multipath planar http://www.citeulike.org/user/dcastro/article/2187906 <i>Antennas and Propagation Society International Symposium, 2001. IEEE, Vol. 4 (2001), pp. 66-69 vol.4.</i><br /><br />The Global Positioning System (GPS) has been used in a variety of applications for which new and more restrictive requirements in the design of the receiving antenna have been introduced. In particular, for high-precision GPS applications, a receiving antenna with superior rejection to multipath signals is required. Furthermore, in order to satisfy the demanded precision and reliability, a high performance GPS antenna must be capable of operation at the two GPS frequencies (1.57542 GHz and 1.2276 GHz). One effective design (see Boccia, L. et al., Microwave and Optical Technology Letters, 2001) demonstrates that consistent multipath mitigation can be obtained with a single frequency shorted annular patch. A stacked shorted elliptical patch, operating at the two GPS bands, is presented. The antenna combines the shorted ring radiation properties, which have proved to comply adequately with multipath mitigation requirements, with dual frequency operations, resulting in a compact high performance dual frequency GPS antenna A high performance dual frequency microstrip antenna for Global Positioning System L Boccia G Amendola G Di Massa doi:10.1109/APS.2001.959401 Antennas and Propagation Society International Symposium, 2001. IEEE, Vol. 4 (2001), pp. 66-69 vol.4. 2008-01-02T12:10:25-00:00 2001 Antennas and Propagation Society International Symposium, 2001. IEEE 4 66 69 vol.4 antenna dual-band gps microstrip http://www.citeulike.org/user/dcastro/article/2187903 <i>Information, Communications and Signal Processing, 2003 and the Fourth Pacific Rim Conference on Multimedia. Proceedings of the 2003 Joint Conference of the Fourth International Conference on, Vol. 2 (2003), pp. 1119-1123 vol.2.</i><br /><br />We report a dual-feed microstrip antenna for operation in the GSM 900/1800 MHz bands and GPS 1575 MHz band. The GPS antenna is right circularly polarized whereas the GSM antenna is linearly polarized. Simulation and measured results are presented for return loss and isolation. An isolation of better than -33dB between the two feed points has been achieved. The overall ground plane size is seen to be smaller than that for a triple-band PIFA design. A triple band antenna for GSM and GPS application MS Yap L Ng S Aditya doi:10.1109/ICICS.2003.1292634 Information, Communications and Signal Processing, 2003 and the Fourth Pacific Rim Conference on Multimedia. Proceedings of the 2003 Joint Conference of the Fourth International Conference on, Vol. 2 (2003), pp. 1119-1123 vol.2. 2008-01-02T12:09:11-00:00 2003 Information, Communications and Signal Processing, 2003 and the Fourth Pacific Rim Conference on Multimedia. Proceedings of the 2003 Joint Conference of the Fourth International Conference on 2 1119 1123 vol.2 antenna dual-band gps gsm http://www.citeulike.org/user/dcastro/article/2187896 <i>Antennas and Wireless Propagation Letters, IEEE, Vol. 3 (2004), pp. 157-160.</i><br /><br />Since the Global Positioning System (GPS) was launched, significant progress has been made in GPS receiver technology but the multipath error remains an unsolved problem. As solutions based on signal processing are not adequate, the most effective approach to discriminate between direct and multipath waves is to specify new and more restrictive criteria in the design of the receiving antenna. An innovative low profile, lightweight dual band (L1+L2) GPS radiator with a high multipath-rejection capability is presented. The proposed solution has been realized by two stacked shorted annular elliptical patch antennas. In what follows, a detailed account of the design process and antenna performances is given, presenting both simulated and experimental results. A dual frequency microstrip patch antenna for high-precision GPS applications L Boccia G Amendola G Di Massa doi:10.1109/LAWP.2004.832127 Antennas and Wireless Propagation Letters, IEEE, Vol. 3 (2004), pp. 157-160. 2008-01-02T12:05:48-00:00 2004 Antennas and Wireless Propagation Letters, IEEE 3 157 160 antenna dual-band gps microstrip patch http://www.citeulike.org/user/dcastro/article/2187889 <i>Antennas and Propagation, IEEE Transactions on, Vol. 45, No. 4. (1997), pp. 698-706.</i><br /><br />The FAA decision allowing the use of the global positioning system (GPS) as a radio navigation and landing help system in the United States commercial airports boosts the need for a high-performance GPS receiver which provides the demanded precision. The design of the receiving antenna is one of the most important parts in the design process, as it has to face significant challenges including uniform coverage of all satellites and the rejection of the multipath signals. The rejection of the multipath signals is accomplished by specifying restrictive criteria to the GPS antenna. This includes a high rejection of the cross-polarized signals and a radiation pattern with a sharp slope for low-elevation angles; that is, near the horizon. The feasibility of using different types of antennas to satisfy restrictive criteria such as dual-frequency coverage (L1 and L2 frequencies), -15 dB cross-polarization rejection, and a beamwidth of more than 130° is discussed. The antenna designs examined in this study include patch antennas, helical antennas, and conical spiral antennas. Two different receiver designs were also examined including a single-antenna system with a hemispherical coverage and an antenna array which may provide independent sectoral coverage or the desired beamwidth. It is shown that a design based on a conical spiral antenna backed with absorbing material may be used to satisfy all the desired specifications. This result was confirmed experimentally Comparative study of high-performance GPS receiving antenna designs N Padros JI Ortigosa J Baker MF Iskander B Thornberg doi:10.1109/8.564096 Antennas and Propagation, IEEE Transactions on, Vol. 45, No. 4. (1997), pp. 698-706. 2008-01-02T12:04:00-00:00 1997 Antennas and Propagation, IEEE Transactions on 45 4 698 706 antenna design gps high performance http://www.citeulike.org/user/dcastro/article/2187888 <i>Antennas and Propagation Society International Symposium, 2002. IEEE, Vol. 4 (2002), pp. 720-723 vol.4.</i><br /><br />Most current GPS receivers only use the L1 frequency of 1.575 GHz with right hand circular polarization. However, in some applications that need more accurate information, differential GPS is employed and an antenna is required to cover both L1 and L2 (1.227 GHz) bands with CP patterns. Recently, we proposed a square patch antenna with switchable slots for dual band CP operation (see Yang, F. and Rahmat-Samii, Y., Electronics Lett., vol.37, p.1002-3, 2001). It has attractive features of a single layer, a single feed, and small frequency ratio. Hence, such an antenna is proposed for GPS applications. The antenna structure and its design procedure are detailed. A single layer dual band circularly polarized microstrip antenna for GPS applications Fan Yang Y Rahmat-Samii doi:10.1109/APS.2002.1017084 Antennas and Propagation Society International Symposium, 2002. IEEE, Vol. 4 (2002), pp. 720-723 vol.4. 2008-01-02T12:03:17-00:00 2002 Antennas and Propagation Society International Symposium, 2002. IEEE 4 720 723 vol.4 antenna circularly dual-band gps microstrip polarisation http://www.citeulike.org/user/dcastro/article/2187859 <i>Antennas and Propagation, IEEE Transactions on, Vol. 45, No. 11. (1997), pp. 1618-1625.</i><br /><br />This paper describes the design and testing of an aperture-coupled circularly polarized antenna for Global Positioning System (GPS) applications. The antenna operates at both the L1 and L2 frequencies of 1575 and 1227 MHz, which is required for differential GPS systems in order to provide maximum positioning accuracy. Electrical performance, low-profile, and cost were equally important requirements for this antenna. The design procedure is discussed, and measured results are presented. Results from a manufacturing sensitivity analysis are also included A dual-band circularly polarized aperture-coupled stacked microstrip antenna for global positioning satellite DM Pozar SM Duffy doi:10.1109/8.650073 Antennas and Propagation, IEEE Transactions on, Vol. 45, No. 11. (1997), pp. 1618-1625. 2008-01-02T11:52:27-00:00 1997 Antennas and Propagation, IEEE Transactions on 45 11 1618 1625 antenna circularly dual-band gps microstrip polarisation http://www.citeulike.org/user/dcastro/article/2183857 <i>Wireless Communication Systems, 2005. 2nd International Symposium on (2005), pp. 601-605.</i><br /><br />Global Positioning System (GPS) is widely used for car-navigation system all over the world. At present, GPS system employs only the frequency of 1.57542 GHz (L1) in the civilian use. Recently, to improve the positioning accuracy, GPS modernization enterprise is scheduled and executing. For the final stage new GPS satellites which will be launched in 2014, additional two new frequency signal transmitters that are for the frequency of 1.22760 GHz (L2) and 1.17645 GHz (L5) will be equipped. Prior to the final stage, the first stage new GPS satellites will be launched in July, 2005. This satellite equips the transmitters for the frequencies of 1.57542 GHz (L1) and 1.22760 GHz (2). In this paper, we propose compact, small, and low profile dual-frequency operation microstrip antennas for this first stage new GPS system. Dual-Frequency Ring Patch Antennas for GPS S Kumagai Y Kazama N Goto doi:10.1109/ISWCS.2005.1547774 Wireless Communication Systems, 2005. 2nd International Symposium on (2005), pp. 601-605. 2007-12-31T18:16:58-00:00 2005 Wireless Communication Systems, 2005. 2nd International Symposium on 601 605 antenna dual-band gps http://www.citeulike.org/user/dcastro/article/1207534 <i>GPS Solutions, Vol. 11, No. 2. (March 2007), pp. 77-83.</i> 10 Hz or 10 s? Schuler Torben doi:10.1007/s10291-006-0034-8 GPS Solutions, Vol. 11, No. 2. (March 2007), pp. 77-83. 2007-04-05T05:53:49-00:00 2007 GPS Solutions 1080-5370 11 2 77 83 Springer gnss gps http://www.citeulike.org/user/dcastro/article/1937025 <i>GPS Solutions, Vol. 11, No. 3. (31 July 2007), pp. 223-226.</i> GPS/GNSS current bibliography Tomás Soler doi:10.1007/s10291-007-0065-9 GPS Solutions, Vol. 11, No. 3. (31 July 2007), pp. 223-226. 2007-11-19T08:48:33-00:00 2007 GPS Solutions 11 3 223 226 bibliography gnss gps http://www.citeulike.org/user/dcastro/article/1915471 <i>Proceedings of the IEEE, Vol. 87, No. 1. (1999), pp. 24-47.</i><br /><br />This paper provides an overview of the next generation of the Global-Positioning System (GPS) space and ground segments as embodied in the GPS Block II follow-on (GPS IIF) program. The GPS IIF program includes the procurement of 33 satellites and the operation and support of the new GPS operational control segment. The program is using the principles of acquisition reform to develop and field a new generation of satellites, support equipment, and software. Performance improvements in GPS signal power, accuracy, and service to civilian users are described. These improvements provide a foundation and, combined with the flexibility of the GPS IIF system, they allow for upgrading the system to even greater capability. The elements of the GPS IIF system are described in significant detail GPS IIF-the next generation SC Fisher K Ghassemi Proceedings of the IEEE, Vol. 87, No. 1. (1999), pp. 24-47. 2007-11-14T19:20:49-00:00 1999 Proceedings of the IEEE 87 1 24 47 gps http://www.citeulike.org/user/dcastro/article/1915432 <i>Electronics, Circuits and Systems, 2000. ICECS 2000. The 7th IEEE International Conference on, Vol. 1 (2000), pp. 352-356 vol.1.</i><br /><br />In this paper, we introduce a novel technique for multipath delay estimation in GPS receivers. The proposed technique is based on a nonlinear quadratic operator called the Teager-Kaiser operator. By applying directly the Teager-Kaiser operator to those correlation functions, we can easily estimate accurately the different multipath delays introduced by the channel. We examine closely the properties of this nonlinear operator when applied to different reference correlation functions, and we provide some simulations to confirm the high efficiency and simple implementation of this new technique Nonlinear operator for multipath channel estimation in GPS receivers R Hamila M Renfors Electronics, Circuits and Systems, 2000. ICECS 2000. The 7th IEEE International Conference on, Vol. 1 (2000), pp. 352-356 vol.1. 2007-11-14T19:14:59-00:00 2000 Electronics, Circuits and Systems, 2000. ICECS 2000. The 7th IEEE International Conference on 1 352 356 vol.1 channel estimation gps multipath receiver tk http://www.citeulike.org/user/dcastro/article/1902890 <i>Aerospace and Electronic Systems Magazine, IEEE, Vol. 18, No. 4. (2003), pp. 3-8.</i><br /><br />Tasks envisioned for future generation Mars rovers - sample collection, area survey, resource mining, habitat construction, etc. - will require greatly enhanced navigational capabilities over those possessed by the Mars Sojourner rover. Many of these tasks will involve cooperative efforts by multiple rovers and other agents, adding further requirements both for accuracy and commonality between users. This paper presents a new navigation system a "Self-Calibrating Pseudolite Array" (SCPA) that can provide centimeter-level, drift-free localization to multiple rovers within a local area by utilizing GPS-based transceivers deployed in a ground-based array. Such a system of localized beacons can replace or augment a system based on orbiting satellite transmitters, and is capable of fully autonomous operations and calibration. This paper describes the prototype SCPA developed at Stanford to demonstrate these capabilities and then presents results from a set of field trials performed at NASA Ames Research Center. These experiments, which utilize the K9 Mars rover research platform, validate both the navigation and self-calibration capabilities of the system. By carrying an on-board GPS transceiver, K9 was successfully able to calibrate the system using no a priori position information and localized the pseudolite beacons to under 5 cm RMS. Mars navigation system utilizes GPS EA Lemaster M Matsuoka SM Rock Aerospace and Electronic Systems Magazine, IEEE, Vol. 18, No. 4. (2003), pp. 3-8. 2007-11-12T14:09:06-00:00 2003 Aerospace and Electronic Systems Magazine, IEEE 18 4 3 8 gps mars navigation system http://www.citeulike.org/user/dcastro/article/1856865 <i>Proceedings of the IEEE, Vol. 87, No. 1. (1999), pp. 3-15.</i> Special Issue on Global Positioning System P Enge P Misra Proceedings of the IEEE, Vol. 87, No. 1. (1999), pp. 3-15. 2007-11-02T17:43:44-00:00 1999 Proceedings of the IEEE 87 1 3 15 gps http://www.citeulike.org/user/dcastro/article/1819733 <i>Vehicular Technology Conference, 2005. VTC 2005-Spring. 2005 IEEE 61st, Vol. 4 (2005), pp. 2624-2628 Vol. 4.</i><br /><br />This paper covers two key points in indoor and dense-urban positioning using Global Navigation Satellite Systems: CN/sub 0/ estimation, and near-far estimation problem. For the former, a novel CN/sub 0/ estimator adequate to deal with the low signal levels encountered in indoor and dense-urban environments is described. For the latter, the results of a novel near-far problem mitigation technique are presented. Both simulations and live data have been used to illustrate the advantages of the proposed algorithms. CN/sub 0/ estimation and near-far mitigation for GNSS indoor receivers G Lopez-Risueno G Seco-Granados Vehicular Technology Conference, 2005. VTC 2005-Spring. 2005 IEEE 61st, Vol. 4 (2005), pp. 2624-2628 Vol. 4. 2007-10-25T08:55:32-00:00 2005 Vehicular Technology Conference, 2005. VTC 2005-Spring. 2005 IEEE 61st 4 2624 2628 Vol. 4 galileo gnss gps indoor multiuser receiver