Descripteur
Documents disponibles dans cette catégorie (250)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
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 PDF The GNSS integer ambiguities / S. Verhagen (2005)
Titre : The GNSS integer ambiguities : estimation and validation Type de document : Monographie Auteurs : S. 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 : Summary
Notation and symbols
Acronyms
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
3.1Integer estimation
3.2Quality 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 robustness
A Mathematics and statistics
A.1 Kronecker product
A.2 Parameter distributions
A.3 Numerical root finding methods
B Simulation and examples
B.1 Simulation
B.2 Examples.
C Theory of BlE estimation
C.1 Integer equivariant ambiguity estimation
C.2 Integer equivarlant unbiased ambiguity estimation
C.3 Best integer equivariant unbiased ambiguity estimation
C.4 Best integer equivariant unbiased baseline estimation
D Implementation aspects of IALS estimationNuméro de notice : 15134 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=55070 Réservation
Réserver ce documentExemplaires(2)
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 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)
[article]
Titre : A review of satellite and airborne sensors for remote sensing based detection of minefields and landmines Type de document : Article/Communication Auteurs : B.H. Maathuis, Auteur ; John L. Van Genderen, Auteur Année de publication : 2004 Article en page(s) : pp 5201 - 5245 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] capteur aérien
[Termes IGN] capteur spatial
[Termes IGN] chambre DTC
[Termes IGN] image Landsat-ETM+
[Termes IGN] Landsat
[Termes IGN] longueur d'onde
[Termes IGN] mine antipersonnel
[Termes IGN] rayonnement proche infrarouge
[Termes IGN] SPOTRésumé : (Auteur) This paper focuses on the use of space and airborne sensors that can be applied to detect landmines and minefields. First the landmine and minefield problem is addressed and examples of the use of remote sensing images are presented that could provide valuable information for the mine action process and assist in conventional minefield and landmine detection methods. This is followed by an overview on relevant (declassified) aspects related to strategic overhead detection techniques developed by the military/intelligence community as well as those of civilian space and airborne remote sensing programmes. The airborne sensing techniques describe the state of the art of sensors such as optical (film, multi- and hyperspectral sensors), thermal infrared as well as microwave sensors and their suitability-limitations for remote sensing based minefield and landmine detection purposes. Numéro de notice : A2004-468 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160412331270803 En ligne : https://doi.org/10.1080/01431160412331270803 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26988
in International Journal of Remote Sensing IJRS > vol 25 n° 23 (December 2004) . - pp 5201 - 5245[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-04211 RAB Revue Centre de documentation En réserve L003 Exclu du prêt The development of superspectral approaches for the improvement of land cover classification / M. Gianinetto in IEEE Transactions on geoscience and remote sensing, vol 42 n° 11 (November 2004)
[article]
Titre : The development of superspectral approaches for the improvement of land cover classification Type de document : Article/Communication Auteurs : M. Gianinetto, Auteur ; G. Lechi, Auteur Année de publication : 2004 Article en page(s) : pp 2670 - 2679 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] bande infrarouge
[Termes IGN] capteur imageur
[Termes IGN] classification dirigée
[Termes IGN] cultures
[Termes IGN] filtrage du bruit
[Termes IGN] image EO1-Hyperion
[Termes IGN] image hyperspectrale
[Termes IGN] image MIVIS
[Termes IGN] Italie
[Termes IGN] Kappa de Cohen
[Termes IGN] occupation du sol
[Termes IGN] onde électromagnétique
[Termes IGN] précision de la classification
[Termes IGN] rapport signal sur bruitRésumé : (Auteur) This paper develops a critical review of the hyperspectral splitting of the solar reflected radiation acquired by hyperspectral imaging sensors. The bandwidth used in the range from 2.0-2.5 um by many hyperspectral sensors sometimes is too narrow for land cover classification. In fact, hyperspectral imagers often suffer from low signal-to-noise (SNR) in the short-wave infrared region of the electromagnetic spectrum, resulting in noisy image collection. This paper presents a new methodological approach to the splitting of the solar reflected radiation, called the "superspectral approach" It is based on the principle of increasing the channel bandwidth by increasing the number of wavelengths, to build synthetic spectral bands with higher SNR. The methodology has been applied to the Multispectral Infrared and Visible Imaging Spectrometer (MIVIS) sensor, an airborne hyperspectral scanner used for environmental remote sensing applications in Italy. Interesting results have been achieved in crop classification, processing the Cordenons survey carried out in August 2001 in the northeastern part of Italy. The Spectral Angle Mapper algorithm was used for classification because it is insensitive to shadows. For accuracy assessment, the overall accuracy (OA) and kappa coefficient (k) were calculated and used in the comparison. Using the superspectral approach, an increment in the overall accuracy of about 42 % and an increment in the kappa coefficient of about 51 % were obtained in comparison to the classification accuracy of unprocessed original MIVIS data (OA = 41.21, k = 0.35). A second case study is presented using the National Aeronautics and Space Administration's experimental hyperspectral imager HYPERION. Data acquired over the lake of Garda (Italy) in October 2002 was processed with the superspectral approach. Comparing the simulated HYPERION superspectral bands with the original data, SNR improvements are achieved in the shortwave infrared region (from 0.7-54.2 for 2.012-pm wavelength and from 0.7-64.5 for the 2.365-pm wavelength). The methodology proposed is sensor independent and can be applied to any of the hyperspectral sensors currently available. Numéro de notice : A2004-464 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2004.835347 En ligne : https://doi.org/10.1109/TGRS.2004.835347 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26984
in IEEE Transactions on geoscience and remote sensing > vol 42 n° 11 (November 2004) . - pp 2670 - 2679[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 065-04111 RAB Revue Centre de documentation Revues en salle Disponible A quantitative measure for the quality of InSAR interferograms based on phase differences / Z. Li in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 10 (October 2004)
[article]
Titre : A quantitative measure for the quality of InSAR interferograms based on phase differences Type de document : Article/Communication Auteurs : Z. Li, Auteur ; W. Zou, Auteur ; X. Ding, Auteur ; Y. Chen, Auteur ; G. Liu, Auteur Année de publication : 2004 Article en page(s) : pp 1131 - 1137 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] image radar moirée
[Termes IGN] phase
[Termes IGN] qualité d'imageRésumé : (Auteur) It is well-known that interferometric SAR (INSAR) is a technology for the generation of high-precision digital elevation models (DEM) and the precise measurement of terrain surface deformation. The accuracy of DEM and deformation measurement is highly dependent on the quality of the interferogram generated. Such an interferogram is constructed by a pointwise complex multiplication of corresponding pixels in both datasets, which are respectively contained in master image and registered image. An exanimation of existing literature reveals that there is no, good, quantitative measure for the quality of interferograms, and visual inspection is still the best solutions available so far. By visual inspection, one recognizes those interferograms with continuous fringes as good ones and regards those with many discontinuous interferograms and speckles as being not good. As the pixels in the interferogram represent the phase value values, it is natural to think that, if the quality is good, the phase differences between neighbor pixels should be small, and thus the sum of all phase differences will still be small. This leads to the proposal of "sum of phase differences" (SPD) as a quantitative measure for the quality of interferogram. Two simulation tests have been conducted, and the results show that the SPD is a reliable measure. Numéro de notice : A2004-361 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.70.10.1131 En ligne : https://doi.org/10.14358/PERS.70.10.1131 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26888
in Photogrammetric Engineering & Remote Sensing, PERS > vol 70 n° 10 (October 2004) . - pp 1131 - 1137[article]Satellite constellation with direct radio measurements for atmospheric studies : WATS mission case / G. Alberti in International Journal of Remote Sensing IJRS, vol 25 n° 18 (September 2004)PermalinkA phase signature for detecting wet subsurface structures using polarimetric L-band SAR / Y. Lasne in IEEE Transactions on geoscience and remote sensing, vol 42 n° 8 (August 2004)PermalinkRefinement of wavelength calibrations of hyperspectral imaging data using a spectrum-machine technique / B.C. Gao in Remote sensing of environment, vol 90 n° 4 (30/04/2004)PermalinkElectromagnetic wave scattering from the sea surface in the presence of wind wave patterns / V. Shrira in International Journal of Remote Sensing IJRS, vol 24 n° 24 (December 2003)PermalinkGeometric processing of hyperspectral image data acquired by VIFIS on board light aircraft / Y. Gu in International Journal of Remote Sensing IJRS, vol 24 n° 23 (December 2003)PermalinkMapping of the tropical forest cover of insular Southeast Asia from SPOT-4 Vegetation images / Hans-Jürgen Stibig in International Journal of Remote Sensing IJRS, vol 24 n° 18 (September 2003)PermalinkSatellites / Michel Capderou (2003)PermalinkModeling and reduction of SAR interferometric phase noise in the wavelet domain / C. Lopez-Martinez in IEEE Transactions on geoscience and remote sensing, vol 40 n° 12 (December 2002)PermalinkCalculation of the calibration constant of polarization Lidar and its dependency on atmospheric temperature / Andreas Behrendt in Optics express, vol 10 n° 16 (12/08/2002)PermalinkATDI, le SIG appliqué à la radio : le mariage de la géomatique et de la radio / Anonyme in Géomatique expert, n° 14 (01/03/2002)Permalink