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Titre : Signal acquisition and tracking for a software GPS receiver Type de document : Mémoire Auteurs : Sophia Y. Zheng, Auteur Editeur : Blacksburg [Virginie - Etats-Unis] : Virginia polytechnic institute and state university Année de publication : 2005 Importance : 60 p. Format : 21 x 30 cm Note générale : bibliographie
thesis submitted to the Faculty of the Virginia Polytechnic Institute and State University in Partial Fulfillment of the Requirements for the Degree of Master of Science in Electrica Engineering.Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] acquisition de données
[Termes IGN] code GPS
[Termes IGN] données GPS
[Termes IGN] onde porteuse
[Termes IGN] récepteur GPS
[Termes IGN] signal GPSRésumé : (auteur) Global Positioning System (GPS) is a satellite-based navigation system that has been used widely both in civilian and military for positioning, navigation, timing and other position related applications. The hardware-based GPS receivers provide the least user flexibility. Thus, it is necessary to have Software-based GPS receivers for easy and quick implementation, simulation and analysis of algorithms. Software-based GPS receiver processes the GPS signal at the radio frequency or intermediate frequency depending on the hardware configuration of the receiver. In this development of the acquisition and tracking processes of the software receiver, the front-end device that converts the radio frequency signal from the antenna to an intermediate frequency is the Mitel 2021 GPS receiver board. An analog-to-digital (A/D) converter then digitizes the output signal from the RF front-end. The data is then processed using MATLAB programs to achieve acquisition and tracking of the GPS signals. The software GPS receiver can perform acquisition and tracking using different parameters and threshold values. This flexibility of operation allows weaker signals to be tracked and processed. In this software receiver design, the focus is on the acquisition and tracking of L1 band C/A code GPS signals used by most civilian applications. The purpose of this thesis is to develop the acquisition and tracking algorithms to extract the navigation data bits from the raw GPS signals. The navigation data bits provide all the necessary information to compute the pseudorange between the receiver and the visible satellites and determine the receiver location. Both MATLAB simulated GPS data and realistic GPS signals from a GSS 6560 simulator are used to verify the performance of the acquisition and tracking programs. The acquisition program is capable of locating the beginning of the C/A code and the carrier frequency to within the desired accuracy. From the output of the acquisition program, the tracking program can decode the navigation data bits. The tracking algorithm implemented is based on the block adjustment of synchronizing signal (BASS) method. Note de contenu : 1. Introduction
1.1. History of GPS
1.2. Structure of GPS
1.3. User position solution
2. GPS signal structure
2.1. GPS signal structure
2.2. The P code
2.3. The C/A code
2.4. Generation of C/A code
2.5. Correlation properties of C/A code
2.6. Navigation data message
2.7. Doppler shift
3. Software GPS receiver
3.1. Advantages of a software GPS receiver
3.2. Software receiver architecture
3.3. Software receiver input signals
4. GPS C/A code signal acquisition
4.1. Factors affecting the acquisition performance
4.2. Acquisition methods
4.3. Performance of the acquisition program
5. Tracking of GPS C/A code signal
5.1. Code tracking
5.2. Carrier tracking
5.3. GPS signal tracking using the BASS method
6. Future workNuméro de notice : 19797 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Mémoire masters divers Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85119 Documents numériques
en open access
Signal acquisition and tracking for a software GPS receiverAdobe Acrobat PDFSpatial resolution and processing tradeoffs for HYDROS: application of reconstruction and resolution enhancement techniques / David G. Long in IEEE Transactions on geoscience and remote sensing, vol 43 n° 1 (January 2005)
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Titre : Spatial resolution and processing tradeoffs for HYDROS: application of reconstruction and resolution enhancement techniques Type de document : Article/Communication Auteurs : David G. Long, Auteur Année de publication : 2005 Article en page(s) : pp 3 - 12 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] accentuation d'image
[Termes IGN] bande L
[Termes IGN] capteur (télédétection)
[Termes IGN] humidité du sol
[Termes IGN] HYDROS
[Termes IGN] Hydrospheric State
[Termes IGN] image à basse résolution
[Termes IGN] mission spatiale
[Termes IGN] radiomètre à hyperfréquence
[Termes IGN] reconstruction d'imageRésumé : (Auteur) Recent developments in reconstruction and resolution enhancement for microwave instruments suggest a possible tradeoff between computation, resolution, and downlink data rate based on postcollection reconstruction/resolution enhancement processing. The Hydrospheric State mission is designed to measure global soil moisture and freeze/thaw state in support of weather and climate prediction, water, energy, and carbon cycle studies, and natural hazards monitoring. It will use an active and passive L-band microwave system that optimizes measurement accuracy, spatial resolution, and coverage. The active channels use synthetic aperture radar-type processing to achieve fine spatial resolution, requiring a relatively high downlink data rate and ground processor complexity. To support real-time applications and processing, an optional postcollection reconstruction and resolution enhancement method is investigated. With this option, much lower rate real-aperture radar data are used along with ground-based postprocessing algorithms to enhance the resolution of the observations to achieve the desired 10-km resolution. Several approaches are investigated in this paper. It is determined that a reconstruction/resolution enhancement technique combining both forward- and aft-looking measurements enables estimation of 10-km resolution or better backscatter values at acceptable accuracy. Key tradeoffs to achieve this goal are considered. Numéro de notice : A2005-057 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2004.838385 En ligne : https://doi.org/10.1109/TGRS.2004.838385 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27195
in IEEE Transactions on geoscience and remote sensing > vol 43 n° 1 (January 2005) . - pp 3 - 12[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-05011 RAB Revue Centre de documentation En réserve L003 Disponible
Titre : The GNSS integer ambiguities : estimation and validation Type de document : Thèse/HDR Auteurs : Sandra Verhagen, Auteur Editeur : Delft : Netherlands Geodetic Commission NGC Année de publication : 2005 Collection : Netherlands Geodetic Commission Publications on Geodesy, ISSN 0165-1706 num. 58 Importance : 170 p. Format : 17 x 24 cm ISBN/ISSN/EAN : 978-90-6132-290-0 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] ambiguïté entière
[Termes IGN] axiome de Bayes
[Termes IGN] code GPS
[Termes IGN] contrôle qualité
[Termes IGN] distribution de Student
[Termes IGN] distribution, loi de
[Termes IGN] estimation statistique
[Termes IGN] Galileo
[Termes IGN] Global Navigation Satellite System
[Termes IGN] Global Orbitography Navigation Satellite System
[Termes IGN] Global Positioning System
[Termes IGN] mesurage de phase
[Termes IGN] méthode des moindres carrés
[Termes IGN] modèle fonctionnel
[Termes IGN] modèle stochastique
[Termes IGN] phase
[Termes IGN] propagation du signal
[Termes IGN] qualité des données
[Termes IGN] résidu
[Termes IGN] résolution d'ambiguïtéIndex. décimale : 30.61 Systèmes de Positionnement par Satellites du GNSS Résumé : (Auteur) Fast and high precision relative positioning with a Global Navigation Satellite System (GNSS) is only possible by using the very precise carrier phase measurements. However, these carrier phases are ambiguous by an unknwon number of cycles. The knowledge that the ambiguities are integer-valued has been exploited in the past 15 years for the development of integer ambiguity resolution algorithms. Once the ambiguities are fixed to their integer values, the carrier phase measurements start to act as if they were very precise pseudorange measurements. [...] Nowadays, the non-trivial problem of integer ambiguity estimation can be considered solved. However, a parameter estimation theory is not complete without the appropriate measures to validate the solution. [...] Obviously, validation of the integer ambiguity solution is still an open problem. Two approaches are investigated here. The first method uses a new ambiguity estimator, the Best Integer Equivariant (BIE) estimator. [...] It was shown that the BIE estimator significantly outperforms the float or fixed solution only in a limited number of cases. Therefore, another new class of integer estimators is investigated : the class of Integer Aperture (IA) estimators. [...] IA estimation has several important advantages. [...] Finally, it is shown that the popular ratio test perform almost as good as the optimal IA estimator if the fixed fail rate approach is used. [...] Note de contenu : 1 Introduction
1.1 Background
1.2 Objectives and contribution of this work
1.3 Outline
2 GNSS observation model and quality control
2.1 Global Navigation Satellite Systems
2.2 GNSS observation equations
2.3 GNSS functional model
2.4 GNSS stochastic model
2.5 Least-squares estimation and quality control
3 Integer ambiguity resolution
3.1 Integer estimation
3.2 Quality of the integer ambiguity solution
3.3 The ambiguity residuals .
3.4 Quality of the fixed baseline estimator
3.5 Validation of the fixed solution
3.6 The Bayesian approach
4 Best Integer Equivariant estimation
4.1 The BIE estimator
4.2 Approximation of the BIE estimator
4.3 Comparison of the float, fixed, and BIE estimators .
4.4 Summary . .
5 Integer Aperture estimation
5.1 Integer Aperture estimation
5.2 Ellipsoidal integer aperture estimation
5.3 Ratio test, difference test and projector test
5.4 Integer Aperture Bootstrapping and LeastSquares .
5.5 Penalized Integer Aperture estimation
5.6 Optimal Integer Aperture estimation
5.7 Implementation aspects
5.8 Comparison of the different IA estimators
5.9 Performance of IA estimation
5.10 Summary
6 Conclusions and recommendations
6.1 Integer estimation and validation
6.2 Quality of the baseline estimators
6.3 Reliability of the results
6.4 Bias robustnessNuméro de notice : 15134 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère DOI : sans En ligne : https://www.ncgeo.nl/downloads/58Verhagen.pdf Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=55070 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 15134-01 30.61 Livre Centre de documentation Géodésie Disponible 15134-02 30.61 Livre Centre de documentation Géodésie Disponible Airborne experimental measurements of the angular variations in surface temperature over urban areas: case study of Marseille (France) / J.P. Lagouarde in Remote sensing of environment, vol 93 n° 4 (15/12/2004)
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Titre : Airborne experimental measurements of the angular variations in surface temperature over urban areas: case study of Marseille (France) Type de document : Article/Communication Auteurs : J.P. Lagouarde, Auteur ; P. Moreau, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 443 - 462 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] correction atmosphérique
[Termes IGN] erreur de mesure
[Termes IGN] Marseille
[Termes IGN] milieu urbain
[Termes IGN] rayonnement infrarouge thermique
[Termes IGN] tâche claire
[Termes IGN] température de luminance
[Termes IGN] température de surface
[Termes IGN] thermographie aérienneRésumé : (Auteur) The directional surface temperatures over urban areas are measured using an airborne TIR camera equipped with wide-angle lenses. The experimental design is described and the possible sources of errors related to the instruments and the atmosphere are analysed and corrections proposed. The data acquisition protocol is adapted to provide directional TIR measurements in a - 60° to + 60° range for zenith and 0 to 360° for azimuth view angles. Two parts of the city of Marseille, the densely built old city centre and a built/vegetated mixture of individual houses and gardens in a suburb, have been studied during summer 2001 in the framework of the UBL-ESCOMPTE project. The results obtained reveal important hot spot effects and differences of surface brightness temperatures varying between - 5 and 7 K between nadir and off-nadir measurements, according to azimuth view angles. Acquisitions performed over the two areas also illustrate the impact of the surface structure and presence of vegetation on the hot spot. An example application for the correction of two temporal series of NOAA 14 and NOAA 16 data is given. Numéro de notice : A2004-460 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2003.12.011 En ligne : https://doi.org/10.1016/j.rse.2003.12.011 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26980
in Remote sensing of environment > vol 93 n° 4 (15/12/2004) . - pp 443 - 462[article]A new method for cross-calibration of two satellite sensors / J.J. Liu in International Journal of Remote Sensing IJRS, vol 25 n° 23 (December 2004)
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Titre : A new method for cross-calibration of two satellite sensors Type de document : Article/Communication Auteurs : J.J. Liu, Auteur ; Z. Li, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 5267 - 5281 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] analyse comparative
[Termes IGN] capteur spatial
[Termes IGN] distribution du coefficient de réflexion bidirectionnelle BRDF
[Termes IGN] étalonnage radiométrique
[Termes IGN] modèle de transfert radiatif
[Termes IGN] Moderate Resolution Imaging Spectroradiometer
[Termes IGN] réflectanceRésumé : (Auteur) Given that many operational satellite sensors are not calibrated, while a handful of research sensors are, cross-calibration between the two types of sensor is a cost-effective means of calibration. A new method of sensor cross-calibration is demonstrated here using the Chinese Multi-channel Visible Infrared Scanning radiometer (MVIRS) and the US Moderate Resolution Imaging Spectrometer (MODIS). MVIRS has six channels, equivalent to the current National Oceanic and Atmospheric Administration's (NOAA) Advanced Very High Resolution Radiometer (AVHRR) and four additional ones for remote sensing of ocean colour and moisture. The MVIRS on-board China's polar-orbiting meteorological satellite (FY-ID) was launched on 15 May 2002 with an earlier overpass time than Terra. The sensor has no on-board calibration assembly. This study attempts to calibrate MVIRS against the well-calibrated MODIS, by taking a series of measures to account for their differences. Clearsky measurements made from the two sensors in July-October 2002 were first collocated. Using the 6S radiative transfer model, MODIS reflectances measured at the top-of-the atmosphere were converted into surface reflectances. They were corrected to the viewing geometry of the MVIRS using the bidirectional reflectance distribution function (BRDF) measured on the ground. The spectral response functions of the two sensors were employed to account for spectral discrepancies. After these corrections, very close linear correlations were found between radiances estimated from the MODIS and the digital readings from the MVIRS, from which the calibration gains were derived. The gains differ considerably from the pre-launch values and are subject to degradation over time. The calibration accuracy is estimated to be less than 5%, which is compatible to that obtained by the more expensive vicarious calibration approach. Numéro de notice : A2004-469 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160412331269779 En ligne : https://doi.org/10.1080/01431160412331269779 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26989
in International Journal of Remote Sensing IJRS > vol 25 n° 23 (December 2004) . - pp 5267 - 5281[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-04211 RAB Revue Centre de documentation En réserve L003 Exclu du prêt A review of satellite and airborne sensors for remote sensing based detection of minefields and landmines / B.H. Maathuis in International Journal of Remote Sensing IJRS, vol 25 n° 23 (December 2004)
PermalinkAutomated road extraction from high resolution multispectral imagery / P. Doucette in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 12 (December 2004)
PermalinkEffets radiométriques en milieu urbain à grande échelle et correction des ombres / Gilles Martinoty in Revue Française de Photogrammétrie et de Télédétection, n° 176 (Décembre 2004)
PermalinkEtude phénoménologique du transfert radiatif en milieu urbain : Dimensionnement d'une campagne aéroportée sur Toulouse pour la détermination des réflectances de surface / Sophie Lacherade in Revue Française de Photogrammétrie et de Télédétection, n° 176 (Décembre 2004)
PermalinkLandsat-5 TM reflective-band absolute radiometric calibration / Gyanesh Chander in IEEE Transactions on geoscience and remote sensing, vol 42 n° 12 (December 2004)
PermalinkRoad extraction using SVM and image segmentation / M. Song in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 12 (December 2004)
PermalinkAssessing the feasibility of a global model for multi-temporal burned area mapping using Spot-Vegetation data / J.M. Silva in International Journal of Remote Sensing IJRS, vol 25 n° 22 (November 2004)
PermalinkDiscrimination potential of X-band polarimetric SAR data / Nicolas Baghdadi in International Journal of Remote Sensing IJRS, vol 25 n° 22 (November 2004)
PermalinkAutomated detection of thermal features of active volcanoes by means of infrared AVHRR records / N. Pergola in Remote sensing of environment, vol 93 n° 3 (15/11/2004)
PermalinkThe use of AVHRR data to determine the concentration of visible and invisible tropospheric pollutants originating from a 1997 forest fire in Southeast Asia / M. Hashim in International Journal of Remote Sensing IJRS, vol 25 n° 21 (November 2004)
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