selection of articles

Transcription

CENTRE de DOCUMENTATION
de l’INSTITUT NATIONAL DE L’INFORMATION
GEOGRAPHIQUE ET FORESTIERE
centrededocumentationdel'IGNcentrededocumentationdel'IGNcentrededocumentationdel'IGNcentrededocumentationdel'IGNcentrededo
cumentationdel'IGNcentrededocumentationdel'IGNcentrededocumentationdel'IGNcentrededocumentationdel'IGNcentrededocumentatio
ndel'IGNcentrededocumentationdel'IGNcentrededocumentationdel'IGNcentrededocumentationdel'IGNcentrededocumentationdel'IGNce
SELECTION OF ARTICLES
referenced between November 1
and December 31, 2011
IN ENGLISH
January 2012
bulletin 23
CENTRE DE DOCUMENTATION DE L'INSTITUT GEOGRAPHIQUE NATIONAL
6/8 Avenue Blaise Pascal - Cité Descartes - Champs sur Marne 77455 Marne la Vallée cedex 2
Tél. : 01.64.15.32.80
Télécopie : 01.64.15.32.84
Mél : [email protected]
Site Web : http://www.ensg.ign.fr
Inside each item, references are ordered by publication date and author alphabetic order.
Contents
Cadastre
3
Digital photogrammetry................................................................................................................................... 3
Image acquisition 3
Image processing 4
Lasergrammetry
7
Navigation and positioning............................................................................................................................... 8
Photogrammetric applications.......................................................................................................................... 9
Physical Geodesy 9
Radar image processing.................................................................................................................................. 11
Remote sensing applications........................................................................................................................... 12
Signal processing 15
Spatial geodesy
15
Spatial geodesy applications........................................................................................................................... 16
Surveying
17
Web geomatics
17
_______________________________________________________________________________________
Centre de Documentation de l’IGN – p. 2
Cadastre
Titre
Auteur(s)
Source
Mots clés
Survey accuracy
BENNETT (R.) et VAN DER MOLEN (P.)
GIM INTERNATIONAL, vol 25, n° 11, [01/11/2011], pp 31 - 35
CADASTRE NUMERIQUE, LEVER CADASTRAL, POSITIONNEMENT PAR GNSS, PRECISION
DES DONNEES
N° notice
A2011-417
Résumé d’auteur Renewed debate on the nature and role of the cadastre was sparked in 2010 through the
forums of FIG 2010 in Sydney, Australia, and GIM International. Six design elements for
‘future cadastres' were discussed, one of them being ‘survey accuracy'. The wide range
of responses regarding this design element implied that the topic required further
clarification. Here, we hope to provide such clarification and further the dialogue on
‘Towards Cadastre 2034'.
Digital photogrammetry
Titre
Auteur(s)
Source
Mots clés
Automatic georeferencing of aerial images using stereo high-resolution satellite
images
OH (J.), TOTH (K.) et GREJNER-BRZEZINSKA (A.)
PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING, vol 77, n° 11, [01/11/2011], pp 1157 - 1168
ALGORITHME RANSAC, COMPENSATION PAR FAISCEAUX, ERREUR DE POSITIONNEMENT,
GEOREFERENCEMENT INDIRECT, IMAGE A HAUTE RESOLUTION, IMAGE AERIENNE,
IMAGE IKONOS, POINT D'APPUI, SIFT (ALGORITHME), VALEUR ABERRANTE
N° notice
A2011-449
Résumé d’auteur For airborne surveys, the GPS/INS system has become the primary source for aerial
image georeferencing. However, alternative automated georeferencing is required to
serve as a backup for georeferencing when GPS/iNS-based georeferencing is not
feasible. High-resolution satellite images (HRSl) have been globally available with better
spatial resolution and increasing positional accuracy. Therefore, HRSI has high potential as
a ground control source for aerial image georeferencing which usually requires accurate
3D ground control points. Unfortunately, single imagery, which is often used as a
reference, contains relief displacement due to objects on the ground introducing
positional errors, unless it is not true orthorectified which is costly and time consuming.
Therefore, in this study, a stereo HRSI-based automated georeferencing approach is
proposed. The use of stereo images can avoid the impact of relief displacement and
requires no external height information. The proposed method is based on a multi-scale
image matching approach utilizing a combination of SIFT (Scale-Invariant Feature
Transform) and RANSAC (RANdom SAmple Consensus). In the georeferencing step, the
bundle adjustment with outlier removal of Baarda's data snooping was utilized.
Experimental results for a strip of aerial images with stereo Ikonos images showed its
potential as a backup system for automated georeferencing.
Image acquisition
Titre
Auteur(s)
Source
Statistical analysis of signal measurement in time-of-flight cameras
MUFTI (F.)
ISPRS JOURNAL OF PHOTOGRAMMETRY AND REMOTE SENSING, vol 66, n° 5, [01/09/2011], pp 720 731
Mots clés
ACQUISITION D'IMAGES, BRUIT, CHAMBRE DE PRISE DE VUES NUMERIQUE, IMAGE 3D,
INTENSITE LUMINEUSE, PHASE, PHOTOGRAPHIE TERRESTRE, RAPPORT SIGNAL SUR
BRUIT, TEMPS DE VOL, TRAITEMENT DU SIGNAL
N° notice
A2011-407
Résumé d’auteur Three-dimensional imaging systems have evolved significantly in the last two decades
due to increase in demand for tasks in the field of close range photogrammetry. The fast
and growing need of 3D imaging devices has given rise to range image technology,
especially time-of-flight (TOF) cameras, that provide direct measurement of distance
between the camera and the targeted surface. A significant advantage of TOF devices
_______________________________________________________________________________________
over traditional range data sensors is their capability to provide frame rate range data
over a full image array. In phase shift TOF cameras, phase shift sampling of the received
signal is used to measure amplitude, phase and the offset (intensity) of the received
signal. As a result, the quality of the measurement of these sensors depends heavily on
signal-to-noise (SNR) of the incoming signal and the subsequent processing algorithms.
A detailed understanding of the statistical distributions of the measurement parameters is
crucial for accurate distance measurement analysis especially in low SNR scenarios. In
this paper, we provide explicit noise models for the three parameters of amplitude, phase
and intensity. The proposed stochastic model helps in investigating the effect of noise on
signal and classifying range data reliability in TOF cameras. The model is used for
prediction of errors in a TOF camera under various SNR conditions. Experimental
verification confirms the validity of the model using real data for range error classification
under different noise conditions.
Titre
Auteur(s)
Source
Mots clés
Calibration of long focal length cameras in close range photogrammetry
STAMATOPOULOS (C.) et FRASER (C.)
PHOTOGRAMMETRIC RECORD, vol 26, n° 135, [01/09/2011], pp 339 - 360
AUTOETALONNAGE, CHAMBRE DE PRISE DE VUES NUMERIQUE, COLINEARITE,
COMPENSATION PAR FAISCEAUX, ETALONNAGE DE CAPTEUR (IMAGERIE), LONGUEUR
FOCALE, PHOTOGRAMMETRIE METROLOGIQUE, PHOTOGRAMMETRIE TERRESTRE
N° notice
A2011-388
Résumé d’auteur One of the practical impediments to the adoption of long focal length lenses in close
range photogrammetry is the difficulty in network exterior orientation and self-calibration
that can be encountered with the collinearity equation model when the camera field of
view is smaller than around 10°. This paper reports on an investigation that examined two
different avenues for improving the self-calibration of long focal length cameras. The first
is a re-examination of the linearisation of the collinearity equations with additional
calibration parameters, and especially determination of the coefficients in the design
matrix corresponding to the interior orientation elements. The second is a new approach
to the calculation of object space coordinates by employing an orthogonal projection
model that can be formulated as a bundle adjustment with self-calibration. Accuracy
aspects of both approaches are discussed and test cases employing both zoom and
macro lenses are presented.
Titre
Auteur(s)
Source
Mots clés
Simultaneous data capture
GRIERSON (H.)
GEOINFORMATICS, vol 14, n° 7, [01/10/2011], pp 6 - 8
ACQUISITIONS SIMULTANEES, CHAMBRE A GRAND FORMAT, CHAMBRE DE PRISE DE
VUES NUMERIQUE, LIDAR, TELEMETRIE LASER AEROPORTE
N° notice
A2011-421
Résumé d’auteur Blom society has a long history and operating a range of digital cameras and sensors
across Europe. Traditionally, these instruments would be used independently, even if
multiple data formats were required. However, the demand for higher quality resources,
and the need for improved capture efficiency, has seen the long established techniques
of aerial surveying put under the microscope. One method to emerge is to use aircraft
with dual sensor capabilities. In early, 2011 Blom UK adapted one of their aeroplanes to
enable simultaneous data capture with their Vexcel large format digital camera and
Optech ALTM LiDAR system.
Image processing
Titre
Auteur(s)
Source
Mots clés
Landslide vulnerability assessment and zonation through ranking of causative
parameters based on landslide density-derived statistical indicators
SHARMA (L.), PATEL (N.), GHOSE (M.) et DEBNATH (P.)
GÉOCARTO INTERNATIONAL, vol 26, n° 6, [01/09/2011], pp 491 - 504
DONNEES STATISTIQUES, EFFONDREMENT DE TERRAIN, INDICE DE RISQUE, RISQUE
NATUREL, SYSTEME D'INFORMATION GEOGRAPHIQUE, VULNERABILITE, ZONE A RISQUE
N° notice
A2011-403
Résumé d’auteur The research presented in this article is based on a new technique governed by three
different statistical indicators determined for each causative parameter, viz. highest
density, average density and coefficient of variation of landslides. Each of these
_______________________________________________________________________________________
indicators was assigned a rank value between 1 and 14 depending upon its variation
among the 14 causative parameters. The aggregate of the three types of rank values
estimate the total ranking value (TRV) for each causative parameter. The study area is
divided into 78,256 spatial units and for each such spatial unit, the influence of the
different causative parameters is determined as the product of the experts' weight of the
associated sub-category and the TRV of the causative parameter that categorizes the
study area into various zones. The efficacy of the proposed technique is demonstrated by
the occurrence of significantly high prediction accuracy of 84%.
Titre
Auteur(s)
Source
Mots clés
Building footprint database improvement for 3D reconstruction: A split and merge
approach and its evaluation
VALLET (B.), PIERROT-DESEILLIGNY (M.), BOLDO (D.) et BREDIF (M.)
ISPRS JOURNAL OF PHOTOGRAMMETRY AND REMOTE SENSING, vol 66, n° 5, [01/09/2011], pp 732 742
BASE DE DONNEES THEMATIQUES, BATI, DONNEES VECTORIELLES, EMPREINTE,
MODELE NUMERIQUE DE SURFACE, POLYGONE, RECONSTRUCTION 3D DU BATI,
SEGMENTATION D'IMAGE, ZONE URBAINE
N° notice
A2011-408
Résumé d’auteur We present a general framework to improve a vectorial building footprint database
consisting of a set of 2D polygons. The aim of this improvement is to make the database
more proper to subsequent 3D building reconstruction at a large scale. Each polygon is
split into several simple polygons guided by a digital elevation model (DEM). We say that
this segmentation is vectorial as we produce segmentations that intrinsically have simple
polygonal shapes, instead of doing a raster segmentation of the DEM within the polygon
then trying to simplify it in a vectorization step. The method is based on a Mumford and
Shah like energy functional characterizing the quality of the segmentation. We simplify
the problem by imposing that the segmentation edges have directions present in the input
polygon over which the DEM is defined. We evaluate the validity of the proposed method
on a very large dataset and discuss its pros and cons based on this evaluation.
Titre
Auteur(s)
Source
Mots clés
Development of a modified neural network-based land cover classification system
using automated data selector and multiresolution remotely sensed data
KHORRAM (S.), YUAN (H.) et VAN DER WIELE (F.)
GÉOCARTO INTERNATIONAL, vol 26, n° 6, [01/10/2011], pp 435 - 457
ANALYSE MULTIRESOLUTION, CARTE DE KOHONEN, CLASSIFICATION PAR RESEAU
NEURONAL, DONNEES MULTICAPTEURS, FUSION D'IMAGES, IMAGE LANDSAT-TM, IMAGE
SPOT, OCCUPATION DU SOL, PERCEPTRON MULTICOUCHES, PRECISION DE LA
CLASSIFICATION
N° notice
A2011-402
Résumé d’auteur Integrating multiple images with artificial neural networks (ANN) improves classification
accuracy. ANN performance is sensitive to training datasets. Complexity and errors
compound when merging multiple data, pointing to needs for new techniques. Kohonen's
self-organizing mapping (KSOM) neural network was adapted as an automated data
selector (ADS) to replace manual training data processes. The multilayer perceptron
(MLP) network was then trained using automatically extracted datasets and used for
classification. Two hypotheses were tested: ADS adapted from the KSOM network
provides adequate and reliable training datasets, improving MLP classification
performance; and fusion of Landsat Thematic Mapper (TM) and SPOT images using the
modified ANN approach increases accuracy. ADS adapted from the KSOM network
improved training data quality and increased classification accuracy and efficiency.
Fusion of compatible multiple data can improve performance if appropriate training
datasets are collected. This proved to be a viable classification scheme particularly where
acquiring sufficient and reliable training datasets is difficult.
Titre
Auteur(s)
Source
Intercomparison and validation of techniques for spectral unmixing of
hyperspectral images: a planetary case study
CEAMANOS (X.), DOUTE (S.) et al.
IEEE TRANSACTIONS ON GEOSCIENCE & REMOTE SENSING, vol 49, n° 11, [01/11/2011], pp 4341 4358
Mots clés
ANALYSE COMPARATIVE, IMAGE HYPERSPECTRALE, SPECTRAL UNMIXING
CLASSIFICATION
N° notice
A2011-447
_______________________________________________________________________________________
Résumé d’auteur As the volume of hyperspectral data for planetary exploration increases, efficient yet
accurate algorithms are decisive for their analysis. In this paper, the capability of spectral
unmixing for analyzing hyperspectral images from Mars is investigated. For that purpose,
we consider the Russell megadune observed by the Compact Reconnaissance Imaging
Spectrometer for Mars (CRISM) and the High-Resolution Imaging Science Experiment
(HiRISE) instruments. In late winter, this area of Mars is appropriate for testing linear
unmixing techniques because of the geographical coexistence of seasonal CO2 ice and
defrosting dusty features that is not resolved by CRISM. Linear unmixing is carried out on
a selected CRISM image by seven state-of-the-art approaches based on different
principles. Three physically coherent sources with an increasing fingerprint of dust are
recognized by the majority of the methods. Processing of HiRISE imagery allows the
construction of a ground truth in the form of a reference abundance map related to the
defrosting features. Validation of abundances estimated by spectral unmixing is carried
out in an independent and quantitative manner by comparison with the ground truth. The
quality of the results is estimated through the correlation coefficient and average error
between the reconstructed and reference abundance maps. Intercomparison of the
selected linear unmixing approaches is performed. Global and local comparisons show
that misregistration inaccuracies between the HiRISE and CRISM images represent the
major source of error. We also conclude that abundance maps provided by three
methods out of seven are generally accurate, i.e., sufficient for a planetary interpretation.
Titre
Auteur(s)
Source
Pixel unmixing in hyperspectral data by means of neural networks
LICCIARDI (G.) et DEL FRATE (F.)
Mots clés
ANALYSE EN COMPOSANTES PRINCIPALES, CLASSIFICATION PAR RESEAU NEURONAL,
IMAGE AHS, IMAGE AVIRIS, IMAGE HYPERSPECTRALE, IMAGE PROBA-CHRIS, REDUCTION
GEOMETRIQUE, SPECTRAL UNMIXING CLASSIFICATION, TEST DE PERFORMANCE
N° notice
A2011-445
Résumé d’auteur Neural networks (NNs) are recognized as very effective techniques when facing complex
retrieval tasks in remote sensing. In this paper, the potential of NNs has been applied in
solving the unmixing problem in hyperspectral data. In its complete form, the processing
scheme uses an NN architecture consisting of two stages: the first stage reduces the
dimension of the input vector, while the second stage performs the mapping from the
reduced input vector to the abundance percentages. The dimensionality reduction is
performed by the so-called autoassociative NNs, which yield a nonlinear principal
component analysis of the data. The evaluation of the whole performance is carried out
for different sets of experimental data. The first one is provided by the Airborne
Hyperspectral Scanner. The second set consists of images from the Compact HighResolution Imaging Spectrometer on board the Project for On-Board Autonomy satellite,
and it includes multiangle and multitemporal acquisitions. The third set is represented by
Airborne Visible/InfraRed Imaging Spectrometer measurements. A quantitative
performance analysis has been carried out in terms of effectiveness in the dimensionality
reduction phase and in terms of the accuracy in the final estimation. The results obtained,
when compared with those produced by appropriate benchmark techniques, show the
advantages of this approach.
Titre
Auteur(s)
Source
Mots clés
SVM-based unmixing-to-classification conversion for hyperspectral abundance
quantification
MIANJI (F.) et ZHANG (Y.)
IEEE TRANSACTIONS ON GEOSCIENCE & REMOTE SENSING, vol 49, n° 11, [01/11/2011], pp ANALYSE INFRAPIXELLAIRE, CLASSIFICATION PAR MACHINE A VECTEURS DE SUPPORT,
CLASSIFICATION SPECTRALE, IMAGE HYPERSPECTRALE, SIGNATURE SPECTRALE,
SPECTRAL UNMIXING CLASSIFICATION
N° notice
A2011-446
Résumé d’auteur Need for a priori knowledge of the components comprising each pixel in a scene has set
the endmember determination, rather than the endmember abundance quantification, as
the primary focus of many unmixing approaches. In the absence of the information about
the pure signatures present in an image scene, which is often the case, the mean spectra
of the pixel vectors, directly extracted from the scene, are usually used as the pure
signatures' spectra. This approach which is mathematically optimized for unmixing
problems with a priori known information ignores some statistical properties of the
extracted samples and leads to a suboptimal solution for real situations. This paper
_______________________________________________________________________________________
proposes a novel learning-based unmixing-to-classification conversion model to treat the
abundance quantification task as a classification problem. Support vector machine, as an
efficient classifier, is used to realize this model. It exploits the statistical nature
(endmember spectral variability) of the extracted endmember representatives from the
hyperspectral scene, rather than solving the problem according to the ideal model in
which only the mean spectra of each training sample set is used. Several experiments
are carried out on simulated and real hyperspectral images. The obtained results validate
the high performance of the proposed technique in abundance quantification which is a
key subpixel information detection capability.
Lasergrammetry
Titre
Auteur(s)
Source
Mots clés
Development of a new laser triangulation system based on an optical frame of
reference
ABZAL (A.), VARSHOSAZ (M.) et SAADATSERESHT (M.)
BALAYAGE LASER, CHAMBRE DE PRISE DE VUES NUMERIQUE, LASERGRAMMETRIE,
PHOTOGRAPHIE TERRESTRE, PRECISION GEOMETRIQUE (IMAGERIE), TRIANGULATION
LOCALE
N° notice
A2011-385
Résumé d’auteur In this paper a new triangulation-based laser scanner is presented which has a simple,
yet strong, flexible and low-cost structure. A digital camera and three laser line projectors
are the main components of the system. One of the laser projectors is positioned
vertically, while the other two are horizontal. The former scans the object, whereas the
latter two establish an optical frame which is used, in part, to define the plane containing
the vertical laser projector at each step of scanning. At each step, an image is taken
which includes the object along with the projected laser lines. By intersecting the vertical
and horizontal lines a couple of points are formed which, along with the calibration
information of the system, enable the extraction of the object coordinates. Results of the
tests carried out show that by using an optical frame of this nature, the process of
scanning is greatly facilitated. That is, the scanner can easily be used to scan objects of
different size and dimensions. Within the current configuration, the system enables
measurements with an accuracy of 1/1600. Also, as the system has a rigorous basis, its
accuracy can be increased if improved hardware is provided.
Titre
Auteur(s)
Source
Mots clés
Terrestrial laser scan error in the presence of dense ground vegetation
COVENEY (S.) et FOTHERINGHAM (A.S.)
DETECTION D'ERREUR, DONNEES LIDAR, DONNEES LOCALISEES 3D, ERREUR
GEOMETRIQUE, FLORE LOCALE, KRIGEAGE, MARAIS SALE, MASQUE DE LA VEGETATION,
SEMIS DE POINTS, SOL NU, SOURCE D'ERREUR, TELEMETRIE LASER TERRESTRE,
VALIDATION DES DONNEES
N° notice
A2011-386
Résumé d’auteur Terrestrial laser scanning (TLS) data-sets are seeing increasing use in geology,
geomorphology, forestry and urban mapping. The ease of use, affordability and
operational flexibility of TLS suggest that demand for it is likely to increase in large-scale
mapping studies. However, its advantages may remain restricted to specific
environments, because of difficulties in defining bare-ground level in the presence of
ground-level vegetation. This paper seeks to clarify the component contributions to TLS
elevation error deriving from vegetation occlusion, scan co-registration error, point cloud
georeferencing error and target position definition in TLS point cloud data. A multi-scan
single-returns TLS point cloud data-set of very high resolution (~250 points/m2) was
acquired for an 11 hectare area of open, substantially flat and 100% vegetated coastal
saltmarsh, providing data for the empirical quantification of TLS error. Errors deriving
from the sources discussed are quantified, clarifying the potential proportional
contribution of vegetation to other error sources. Initial data validation is applied to the
TLS point cloud data after application of a local-lowest-point selection process, and
repeat validation tests are applied to the resulting filtered point cloud after application of a
kriging-based error adjustment and data fusion with GPS. The final results highlight the
problem of representing bare ground effectively within TLS data captured in the presence
_______________________________________________________________________________________
of dense ground vegetation and clarify the component contributions of elevation error
deriving from surveying and data processing.
Titre
Auteur(s)
Source
Mots clés
A volumetric approach to population estimation using lidar remote sensing
LU (Z.), IM (J.) et QUACKENBUSH (L.)
DETECTION DU BATI, DONNEES LIDAR, ESTIMATION STATISTIQUE, HABITAT URBAIN, ILOT,
LASERGRAMMETRIE, POPULATION URBAINE, RECENSEMENT DEMOGRAPHIQUE,
REGRESSION, VOLUME (GRANDEUR), ZONE URBAINE
N° notice
A2011-448
Résumé d’auteur This research investigated the applicability of lidar data for estimating population at the
census block level using a volumetric approach. The study area, near the urban
downtown area of Denver, Colorado, was selected since it includes dense distribution of
different types of residential buildings. A modified morphological building detection
algorithm was proposed to extract buildings from the lidar-derived surfaces. The
extraction results showed that the modified morphological building detection algorithm
can effectively recover building pixels occluded by nearby trees. The extracted buildings
were further refined to residential buildings using parcel data. Two approaches (i.e., areaand volume-based) to population estimation were investigated at the census block level.
Four regression models (i.e., simple linear regression, multiple linear regression,
regression tree using one variable, and regression tree using multiple variables) were
used to identify the relationship between census population and the area or volume
information of the residential buildings. The volume-based models over-whelmingly
outperformed the area-based models in the study area, and the models using multiple
variables yielded more accurate estimation than the single variable models. The volumebased regression tree model using multiple variables yielded the most accurate
estimations: R2 = 0.89, RMSE = 21 people, and RRMSE = 26.8 percent in the calibration
site; and R2 = 0.80, RMSE = 27 people, and RRMSE = 30.1 percent in the validation site.
As the results show, the volumetric approach using lidar remote sensing is effective for
population estimation in regions with heterogeneous housing characteristics.
Titre
Auteur(s)
Source
Mots clés
Lidar online: Analysing earthquake damage
TORRO (R.), GARCIA (J.) et GARCIA (R.)
ANALYSE DIACHRONIQUE, DIFFUSION DE DONNEES, DOMMAGE, DONNEES LIDAR,
RISQUE NATUREL, SEISME, VISUALISATION 3D
N° notice
A2011-416
Résumé d’auteur On 11th May 2011, two earthquakes with their epicentres in Lorca caused significant
damaged in the region of Murcia, Spain. A new flight was carried out in the region three
days after the earthquake to obtain more accurate Lidar data to supplement the data that
was already available thanks to the PNOA project from 2009. The new Lidar data was
also made available to anyone who needed it, allowing the damage to be assessed
quickly and efficiently. In the case of a natural disaster, releasing data obtained both from
flights beforehand and afterwards allows relevant users to create an inventory of the
damage and detect any changes quickly and accurately using the appropriate tools.
Navigation and positioning
Titre
Auteur(s)
Source
Mots clés
Filling in the gaps: Improving navigation continuity using parallel cascade
identification
IQBAL (U.), GEORGY (J.), KORENBERG (M.) et NOURELDIN (A.)
GPS WORLD, vol 22, n° 10, [01/10/2011], pp 42 - 49
CENTRALE INERTIELLE, FILTRAGE DU BRUIT, FILTRE DE KALMAN, GNSS ASSISTE POUR
LA NAVIGATION, GPS-INS, NAVIGATION EMBARQUEE, POSITIONNEMENT PAR GPS,
TRAITEMENT DU SIGNAL
N° notice
A2011-420
Résumé d’auteur To reliably navigate with fewer than four satellites, GPS pseudoranges need to be
augmented with measurements from other sensors, such as a reduced inertial sensor
system or RISS. What is the best way to combine the RISS measurements with the GPS
measurements? The classic approach is to integrate the measurements in a conventional
tightly coupled Kalman filter. But in this month’s column, we look at how a mathematical
_______________________________________________________________________________________
procedure called parallel cascade identification can improve the Kalman filter’s job, when
navigating with three, two, or even one GPS satellite.
Titre
Auteur(s)
Source
Mots clés
N° notice
Résumé doc.
Expert advice: Realizing Europe's SatNav ambitions
POMIES (A.) et UELAND (G.)
GPS WORLD, vol 22, n° 11, [01/11/2011], pp 10 - 13
GALILEO, GLOBAL NAVIGATION SATELLITE SYSTEM
A2011-438
Bilans et espoirs de l'Europe vis à vis du GNSS, du point de vue de Galileo Services.
Photogrammetric applications
Titre
Auteur(s)
Source
Mots clés
Surveying buildings: Point clouds and multi-image panoramas
COLOMBO (L.) et MARANA (B.)
DONNEES LIDAR, DONNEES LOCALISEES 3D, IMAGE TERRESTRE, LASERGRAMMETRIE,
MODELISATION 3D, MONUMENT HISTORIQUE, PHOTOGRAMMETRIE TERRESTRE,
RECONSTRUCTION 3D DU BATI, SURVEILLANCE D'OUVRAGE, TEXTURE D'IMAGE
N° notice
A2011-422
Résumé d’auteur The development of building knowledge systems is nowadays a meaningful step when
planning architectural maintenance and managing emergencies during a building's life
cycle. A 3D photo-textured model, which can describe both spatial connections and
material properties, is a measurable virtual object that is achieved via terrestrial survey
techniques, such as laser scanning and imaging. This article presents the current status
of techniques and technologies for the construction of a textured model, through the
support of experiences regarding an ancient historical building in the Lombardy region of
Northern Italy.
Titre
Auteur(s)
Source
Mots clés
Cultural heritage data acquisition and processing: a report on the ISPRS York 2011
conference
PETRIE (G.)
DONNEES DESCRIPTIVES, DONNEES LOCALISEES 3D, LASERGRAMMETRIE, PATRIMOINE
ARCHEOLOGIQUE, PATRIMOINE IMMOBILIER, PHOTOGRAMMETRIE TERRESTRE, SITE
ARCHEOLOGIQUE
N° notice
A2011-423
Résumé d’auteur The development of the new close-range digital imaging, photogrammetric and laser
scanning technologies is having a huge impact on the measurement, recording, depiction
and analysis of cultural heritage sites and objects world-wide - as revealed at the recent
ISPRS conference held in York, England.
Physical Geodesy
Titre
Auteur(s)
Source
Mots clés
Assessment of systematic errors in the computation of gravity gradients from
satellite altimeter data
BOUMAN (J.), BOSCH (W.) et SEBERA (J.)
MARINE GEODESY, vol 34, n° 2, [01/04/2011], pp 85 - 107
ALTIMETRIE SATELLITAIRE PAR RADAR, CHAMP DE PESANTEUR TERRESTRE, DONNEES
ALTIMETRIQUES, DONNEES GOCE, ERREUR SYSTEMATIQUE, GEOIDE OCEANIQUE,
GRADIENT DE GRAVITATION, OCEANOGRAPHIE DYNAMIQUE
N° notice
A2011-409
Résumé d’auteur With satellite radar altimetry, the oceanic geoid can be determined with high precision and
resolution. Double differentiation of these data along satellite altimeter ground tracks
yields along-track gravity gradients that can be used to compute vertical gravity gradients
at ground track crossovers. One way to counteract the noise amplification due to the
differentiation is to smooth the data using smoothing splines. Although the effect of
satellite altimeter data noise has been investigated to some extent, the associated
systematic errors have not been assessed so far. Here we show that some of the
systematic errors cannot be neglected. In particular, we found that the negligence of the
_______________________________________________________________________________________
dynamic ocean topography (DOT) may introduce errors that are greater than the
measurement noise induced errors. If the gravity gradients are to be used for GOCE
validation, then also in this case the DOT may not be neglected as the signal at GOCE
altitude of 260 km may be above the GOCE requirements. In addition, we show that the
altimetry derived gravity gradients cannot be compared one-to-one with those in a local
Cartesian frame. The differences are small compared with the total signal, but they may
be larger than the satellite altimetry induced stochastic errors and may be above the
GOCE requirements. The cubic splines second derivative truncation error requires the
use of 10 Hz altimeter data for the computation of gravity gradients at the Earth's surface,
while 1 Hz data are sufficient for validation at GOCE altitude.
Titre
Auteur(s)
Source
Mots clés
Strapdown INS/DGPS airborne gravimetry tests in the Gulf of Mexico
LI (X.)
JOURNAL OF GEODESY, vol 85, n° 9, [01/09/2011], pp 597 - 605
CENTRALE INERTIELLE, DONNEES GPS, FORCE DE GRAVITATION, GPS EN MODE
DIFFERENTIEL, GPS-INS, GRAVIMETRIE AERIENNE, TEST DE PERFORMANCE
N° notice
A2011-376
Résumé d’auteur Combining data from a Strapdown Inertial Navigation System and a Differential Global
Positioning System (SINS/DGPS) has shown great promise in estimating gravity on
moving platforms. Previous studies on a ground-vehicle system obtained 1–3 mGal
precision with 2 km spatial resolution. High-accuracy Inertial Measurement Units (IMU)
and cm-level positioning solutions are very important in obtaining mGal-level gravity
disturbance estimates. However, these ideal configurations are not always available or
achievable. Because the noise level in the SINS/DGPS gravimetric system generally
decreases with an increase of speed and altitude of the platform, the stringent constraints
on the IMU and GPS may be relieved in the airborne scenario. This paper presents an
investigation of one navigation-grade and one tactical-grade IMU for the possibility of lowcost INS/GPS airborne gravimetry. We use the data collected during the Gravity-Lidar
Study of 2006 (GLS06), which contains aerogravity, GPS, and INS along the northern
coastline of the Gulf of Mexico. The gravity disturbance estimates from the navigationgrade IMU show 0.5–3.2 mGal precision compared with the onboard gravimeter’s
measurements and better than 3 mGal precision compared with the upward continued
surface control data. Due to relatively large (240 s) smoothing window, the results have
about 34 km along-track resolution. But the gravity estimates from the tactical-grade IMU
have much poorer precisions. Nonetheless, useful contributions from the tactical-grade
IMU could be extracted for longer wavelengths.
Titre
Auteur(s)
Source
Mots clés
Alternative method for angular rate determination within the GOCE gradiometer
processing
STUMMER (C.), FECHER (T.) et PAIL (R.)
CHAMP DE PESANTEUR TERRESTRE, DONNEES GOCE, FILTRE DE WIENER,
GRADIOMETRIE, ORIENTATION DU CAPTEUR, VITESSE ANGULAIRE
N° notice
A2011-375
Résumé d’auteur The most crucial part of the GOCE gradiometer processing is, besides the internal
calibration of the gradiometer, the determination of the satellite’s inertial angular rate.
This paper describes a new method for the angular rate determination. It is based on the
stochastic properties of the GOCE star sensors and the gradiometer. The attitude
information of both instrument types is combined at the level of angular rates. The
combination is done in the spectral domain by Wiener filtering, and thus using an optimal
relative weighting of the star sensor and gradiometer attitude information. Since the
complete processing chain from raw measurements to gravity field solutions is
performed, the results are not only analyzed at the level of gravity gradients, but also of
gravity field solutions. Compared to the nominal method, already the resulting gravity
gradients show a significantly improved performance for the frequencies (mainly) below
the gradiometer measurement bandwidth. This can be verified by analysis of the gravity
gradient trace. The improvement is propagated to the level of gravity field models, where
a better accuracy can be observed for selected groups of coefficients at characteristic
bands at orders k x 16, with integer k, up to high harmonic degrees.
Titre
Sensitivity of superconducting gravimeters in central Europe on variations in
regional river and drainage basins
_______________________________________________________________________________________
Auteur(s)
Source
Mots clés
KRONER (C.) et WEISE (A.)
ANALYSE DE SENSIBILITE, BARRAGE, BASSIN HYDROGRAPHIQUE, CHAMP DE
PESANTEUR LOCAL, CHAMP DE PESANTEUR TERRESTRE, GRAVIMETRE
SUPRACONDUCTEUR, GRAVIMETRIE, MODELE HYDROGRAPHIQUE, VARIATION
N° notice
A2011-434
Résumé d’auteur As underpinned by various studies in the last years, temporal changes of the Earth’s
gravity field contain a wealth of information on mass redistribution processes in the
Earth’s system particularly associated with variations in continental water storage. By
combining satellite and terrestrial observations with superconducting gravimeters (SG) a
maximum of information can be gained due to the different temporal and spatial
sampling. Esp. the cluster of superconducting gravimeters in central Europe is well suited
for studies related to spatial and temporal changes in continental water storage. Due to
the distribution of SG sites different sensitivities of the instruments are to be expected on
changes in the various river and drainage basins which could, if sufficiently pronounced,
be deployed to pinpoint areas in which main discrepancies between modelled and actual
water storage changes occur and would thus allow us to fine-tune hydrological models.
Based on the Water-Gap Global Hydrological Model (WGHM), this sensitivity of the SG
observations is investigated. One compartment of the WGHM is surface water, thus
comprising rivers, flooding areas, and major reservoirs. This contribution is given for the
total cell of 0.5◦ × 0.5◦ and not localized, e.g. in a riverbed, therefore the question arises
to which extent localization or non-localization of this compartment affects the estimate if
the respective surface waters are in the vicinity of 50km around the SG stations. It can be
shown, however, that the lateral distribution of the surface water masses plays only a
negligible role for the central European stations meaning distributed surface water
masses are an acceptable simplification when estimating hydrological effects. It emerges
that variations in water storage in regions outside central Europe produce comparable
effects on gravity at all sites and the impact of basins within central Europe is clearly
distinguishable among the SG stations.
Radar image processing
Titre
Auteur(s)
Source
Geolocation and stereo height estimation using TerraSAR-X spotlight image data
ELDHUSET (K.) et WEYDAHL (D.)
Mots clés
COIN REFLECTEUR, GEOREFERENCEMENT DIRECT, HAUTEUR DU BATI, IMAGE
TERRASAR-X, PRECISION DU POSITIONNEMENT, TACHE CLAIRE
N° notice
A2011-426
Résumé d’auteur We have studied the geographic position of several high-resolution spotlight TSX images
by investigating the location of deployed radar corner reflectors. Results show that the
geolocation accuracy is better than the resolution cell in both azimuth and range
directions. The same corner reflectors as well as distinct points on buildings are used to
estimate the absolute height from stereo viewing spotlight TSX images to within a few
decimeters accuracy.
Titre
Auteur(s)
Source
Performance requirements for ionospheric correction of low-frequency SAR data
MEYER (J.)
Mots clés
BANDE L, BANDE P, CORRECTION IONOSPHERIQUE, IMAGE RADAR MOIREE,
INTERFEROMETRIE PAR RADAR A ANTENNE SYNTHETIQUE
N° notice
A2011-427
Résumé d’auteur In recent years, significant progress has been made in developing theory and methods for
modeling, detecting, and correcting ionospheric effects in low-frequency synthetic
aperture radar (SAR) data. While a large number of correction methods have been
developed that differ in sensitivity, data needs, and spatiotemporal accuracy, a lack of
performance requirements for ionospheric correction has prevented an evaluation of their
suitability for operational implementation. Hence, this paper focuses on the development
of performance requirements for the correction of ionospheric effects in low-frequency
SAR data. The requirements are derived considering the data quality needs of a set of
_______________________________________________________________________________________
SAR applications and will ensure the SAR data after ionospheric correction to meet
calibration specifications and maintain full performance during all ionospheric conditions.
The proposed requirements can serve as a benchmark for a performance assessment of
ionospheric correction methods and will help define their suitability for operational
implementation. Requirements are determined for SAR polarimetry, SAR imaging, SAR
interferometry, and ionospheric research.
Titre
Auteur(s)
Source
Radar backscatter mapping using TerraSAR-X
RIZZOLI (P.), BRAUTIGAM (B.), WOLLSTADT (S.) et MITTERMAYER (J.)
Mots clés
BANDE X, IMAGE RADAR, IMAGE TANDEM-X, IMAGE TERRASAR-X, MOSAIQUAGE
D'IMAGES, RETRODIFFUSION
N° notice
A2011-425
Résumé d’auteur Global backscatter data can be used for accurate synthetic aperture radar (SAR)
performance estimation and optimizing instrument settings for SAR systems, e.g. the
TerraSAR-X mission (TSM) and the TanDEM-X mission (TDM). The goal of this work is
the generation of X-band backscatter maps by mosaicking images acquired by the TSM.
An algorithm that allows the estimation of the on-ground backscatter, for any required
polarization and incidence angle from the available data, is implemented. In this paper,
the backscatter map generation algorithm is presented, together with the first results,
obtained from the TSX-1 data. The validity of the interpolation models is also discussed,
as they will form the basis for a future global statistical analysis and modeling of
backscatter behavior in X-band SAR data.
Titre
Auteur(s)
Source
Interference suppression algorithm for SAR based on time-frequency transform
ZHANG (S.), XING (X.) et al.
Mots clés
FILTRE PASSE-BANDE, IMAGE RADAR, IMAGE SAR, INTERFERENCE, TRANSFORMATION
DE FOURIER, TRANSFORMATION EN ONDELETTES
N° notice
A2011-428
Résumé d’auteur The goal of this paper is to suppress the narrowband interference (NBI) and wideband
interference (WBI) in synthetic aperture radar (SAR) by using a nonparametric method.
The method is based on the analysis of time-frequency characteristic of NBI and WBI
from which an interference suppression filter combined with the constant false alarm rate
algorithm is designed. In this approach, the short-time Fourier transform (STFT) is used
to estimate the instantaneous frequency of the SAR echo data with interference. In the
STFT domain, the instantaneous frequency spectrum is represented by wavelet, and
then, the designed filter filters the corresponding wavelet coefficients of the interference
components. In addition, this algorithm is robust to time-varying NBI and WBI. The
performance of the proposed approach is evaluated by the simulated and measured data,
and the effectiveness is demonstrated.
Remote sensing applications
Titre
Auteur(s)
Source
Mots clés
Automated damage indication for rapid geospatial reporting
TIEDE (D.), LANG (S.) et al.
BATI, CATASTROPHE NATURELLE, DOMMAGE, ESTIMATION STATISTIQUE, EXTRACTION
AUTOMATIQUE, IMAGE A HAUTE RESOLUTION, IMAGE SATELLITE, ORGANISATION DU
TRAVAIL, SUPERPOSITION D'IMAGES
N° notice
A2011-382
Résumé d’auteur A methodology for automated extraction of damage indication from very high spatial
resolution satellite imagery is presented for the Haitian towns of Carrefour and Leogane
following the January 2010 earthquake. Damaged buildings are identified by changes to
their shadows between pre- and post-event data. The approach makes use of objectbased image analysis concepts to extract relevant information on damage distribution.
The methodology selected requires pre-and post-disaster images with similar sun angles
and will only be suitable for the detection of collapsed (or partly collapsed) structures. The
new methodology proved to be effective for the Carrefour area despite using satellite
_______________________________________________________________________________________
images of different qualities with inadequate image (co-)registration, producing positively
validated results within an acceptable processing time, and was, to the best of our
knowledge, the only automated damage assessment method to have delivered
appropriate results to requesting relief organizations within a few days of the Haiti
earthquake.
Titre
Auteur(s)
Source
Mots clés
Geospatial disaster response during the Haiti earthquake: A case study spanning
airborne deployment, data collection, transfer, processing, and dissemination
VAN AARDT (J.), MCKEOWN (D.), FAULRING (J.) et al.
CATASTROPHE NATURELLE, DIFFUSION DE DONNEES, DOMMAGE, DONNEES
LOCALISEES, DONNEES MULTISOURCES, IMAGE AERIENNE, SEISME, TELEDETECTION
AERIENNE, TRAITEMENT DE DONNEES LOCALISEES
N° notice
A2011-383
Résumé d’auteur Immediately following the 12 January 2010 earthquake in Haiti, a disaster response team
from Rochester Institute of Technology, ImageCat Inc., and Kucera Internationa!, funded
by the Global Facility for Disaster Reduction and Recovery group of the World Bank,
collected 0.15 m airborne imagery and two points/m 2 lidar data for 650 km 2 over a period
of seven days. Data were transferred to Rochester, New York for processing at rates that
approached 400 Mb/s using Internet2, orthorectified with a 24-hour turnaround, and
distributed to response agencies through file or disk transfer. A unique response effort,
dubbed the Global Earth Observation - Catastrophe Assessment Network (GEO-CAN) and
headed by ImageCat, utilized over 600 experts from 23 different countries to generate
rapid turnaround damage assessment products. This paper highlights the airborne data
collection, transfer, processing, and product development effort, which arguably has
raised the bar in terms of response to large-scale disasters.
Titre
Auteur(s)
Source
Mots clés
Rapid-damage assessment and situation mapping: learning from the 2010 Haïti
earthquake
VOIGT (S.), SCHNEIDERHAN (T.) et al.
CARTE ETRANGERE, CARTE THEMATIQUE, COHERENCE DES DONNEES, DOMMAGE,
DONNEES MULTISOURCES, KOPERNIKUS, ORGANISATION DU TRAVAIL, RISQUE
NATUREL, SEISME, SPATIOCARTE
N° notice
A2011-381
Résumé d’auteur The paper reports on the activity of the Center for Satellite based Crisis Information (ZKI)
of the German Aerospace Center (DIM) in the aftermath of the devastating earthquake in
Port-au-Prince, Haiti on 12 January 2010. DLR/ZKI closely coordinated with the
European Global Monitoring for Environment and Security (GMES) program and the
International Charter Space and Major Disasters, AH DLH/ZKI damage maps are based on
a specific analysis approach, including preprocessing procedures and visual
interpretation on a grid-basis. As the satellite-based mapping response globally was so
extensive for this event, problems resulting from the large number and inconsistency of
satellite maps generated internationally are addressed. In order to avoid this kind of
"mapping challenge" in future the setting-up of an international working group to
elaborate global guidelines and cooperation procedures for better coherence of
international satellite rapid mapping efforts for extreme events such as the Haiti
earthquake is suggested.
Titre
Auteur(s)
Source
Mots clés
Seismic-zonation of Port-au-Prince using pixel- object-based imaging analysis
methods on Aster GDEM
YONG (S.), HOUGH (E.), COX (E.) et al.
ANALYSE D'IMAGE NUMERIQUE, CARTOGRAPHIE THEMATIQUE, CLASSIFICATION
PIXELLAIRE, DONNEES MULTITEMPORELLES, IMAGE TERRA-ASTER, MODELE
NUMERIQUE DE TERRAIN, SEISME, ZONE A RISQUE
N° notice
A2011-380
Résumé d’auteur We report about a preliminary study to evaluate the use of semi-automated imaging
analysis of remotely-sensed DEM and field geophysical measurements to develop a
seismic-zonation map of Port-au-Prince, Haiti. For in situ data, V s30 values are derived
from the MASW technique deployed in and around the city. For satellite imagery, we use an
ASTER GDEM of Hispaniola. We apply both pixel- and object-based imaging methods on
the ASTER GDEM to explore local topography (absolute elevation values) and classify terrain
_______________________________________________________________________________________
types such as mountains, alluvial fans and basins/near-shore regions. We assign NEHRP
seismic site class ranges based on available V s30 values. A comparison of results from
imagery-based methods to results from traditional geologic-based approaches reveals
good overall correspondence. We conclude that image analysis of RS data provides
reliable first-order site characterization results in the absence of local data and can be
useful to refine detailed site maps with sparse local data.
Titre
Auteur(s)
Source
Mots clés
Evaluation of the RPC model as a replacement for the spaceborne InSAR phase
equation
ZHANG (G.), FEI (W.), LI (Z.) et al.
AJUSTEMENT DE PARAMETRE, IMAGE RADAR, INTERFEROMETRIE PAR RADAR A
ANTENNE SYNTHETIQUE, MODELE GEOMETRIQUE DE PRISE DE VUE, MODELE PAR
FONCTIONS RATIONNELLES, PHASE
N° notice
A2011-387
Résumé d’auteur Synthetic aperture radar interferometry (InSAR) is an alternative to conventional
stereoscopic SAR for extracting relative or absolute terrain elevation information.
However, for different InSAR data-sets, the auxiliary parameters are different, which
introduces differences in the SAR interferometry rigorous sensor model (RSM). The
Rational Polynomial Coefficient (RPC) model is a generalised sensor model which makes
full use of the auxiliary parameters of the satellite images, and the coefficients of the
model are then solved by fitting the model to the RSM. Some work has been carried out
previously to validate its substitutability for the SAR RSM, which is based on the Range–
Doppler equations. Further, this paper aims to prove that the RPC model can also be
used as a replacement for the InSAR phase equation and can be widely applied on
different types of InSAR data-sets. Based on numerous tests, the modelling error of the
RPC is analysed. This study found that the RPC model is suitable for InSAR data-sets
and it can be used as a replacement for the phase equation.
Titre
Auteur(s)
Source
Mots clés
Damage assessment of 2010 Haïti earthquake with post-earthquake satellite image
by support vector selection and adaptation
KAYA (G.), MUSAOGLU (N.) et ERSOY (O.)
ANALYSE COMPARATIVE, CARTE THEMATIQUE, CATASTROPHE NATURELLE,
CLASSIFICATION MULTITEMPORELLE, CLASSIFICATION PAR MACHINE A VECTEURS DE
SUPPORT, DOMMAGE, IMAGE SATELLITE, SEISME
N° notice
A2011-433
Résumé d’auteur Remote sensing technology is a powerful tool to extract regions damaged after an
earthquake. There are two methodological approaches in detection of earthquake
damage: mono-temporal and multi-temporal. Especially for providing effective emergency
management, the mono-temporal approach is generally preferred in extraction of
earthquake damage as it does not depend on availability of pre-earthquake imagery. For
this purpose, a novel method called support vector selection and adaptation (SVSA) has
been introduced to detect the damaged regions from a post-earthquake image. In this
study, the SVSA method was applied to the region where the Haiti Presidential Palace
and Cathedral is located, and the damaged regions were identified. The performance of
the SVSA method in identification of the damaged regions was evaluated by comparing
the thematic maps obtained by classifying pre- and post-earthquake images. Additionally,
the damage patterns for the city of Port-au-Prince were estimated by the SVSA.
_______________________________________________________________________________________
Signal processing
Titre
Auteur(s)
Source
Mots clés
Interpolating atmospheric water vapor delay by incorporating terrain elevation
information
XU (B.), LI (Z.W.) et ZHU (J.)
DEGRADATION DU SIGNAL, INTERFEROMETRIE PAR RADAR A ANTENNE SYNTHETIQUE,
INTERPOLATION SPATIALE, MODELE NUMERIQUE DE SURFACE, PROPAGATION DU
SIGNAL, SIGNAL GPS, SIGNAL RADAR, VAPEUR D'EAU
N° notice
A2011-374
Résumé d’auteur In radio signal-based observing systems, such as Global Positioning System (GPS) and
Interferometric Synthetic Aperture Radar (InSAR), the water vapor in the atmosphere will
cause delays during the signal transmission. Such delays vary significantly with terrain
elevation. In the case when atmospheric delays are to be eliminated from the measured
raw signals, spatial interpolators may be needed. By taking advantage of available terrain
elevation information during spatial interpolation process, the accuracy of the
atmospheric delay mapping can be considerably improved. This paper first reviews three
elevation-dependent water vapor interpolation models, i.e., the Best Linear Unbiased
Estimator in combination with the water vapor Height Scaling Model (BLUE + HSM), the
Best Linear Unbiased Estimator coupled with the Elevation-dependent Covariance Model
(BLUE + ECM), and the Simple Kriging with varying local means based on the Baby
semi-empirical model (SKlm + Baby for short). A revision to the SKlm + Baby model is
then presented, where the Onn water vapor delay model is adopted to substitute the
inaccurate Baby semi-empirical model (SKlm + Onn for short). Experiments with the
zenith wet delays obtained through the GPS observations from the Southern California
Integrated GPS Network (SCIGN) demonstrate that the SKlm + Onn model outperforms
the other three. The RMS of SKlm + Onn is only 0.55 cm, while those of BLUE + HSM,
BLUE + ECM and SKlm + Baby amount to 1.11, 1.49 and 0.77 cm, respectively. The
proposed SKlm + Onn model therefore represents an improvement of 29–63% over the
other known models.
Titre
Auteur(s)
Source
Mots clés
Space-time equalization techniques for new GNSS signals
ANANTHARAMU (P.), BORIO (D.) et LACHAPELLE (G.)
GPS WORLD, vol 22, n° 10, [01/10/2011], pp 36 - 41
ANTENNE GNSS, DONNEES SPATIOTEMPORELLES, SIGNAL GNSS, TRAITEMENT DU
SIGNAL
N° notice
A2011-419
Résumé d’auteur Spatial and temporal information of signals received from multiple antennas can be
applied to mitigate the impact of new GPS and Galileo signal's binary-offset sub-carrier,
reducing multipath and interference effects.
Spatial geodesy
Titre
Auteur(s)
Source
Mots clés
High-precision GNSS receivers
BLANCO-DELGADO (N.)
INTERFERENCE, PERTURBATION IONOSPHERIQUE, POSITIONNEMENT PAR GNSS,
QUALITE DES DONNEES, RECEPTEUR GNSS, SIGNAL GNSS, VENT SOLAIRE
N° notice
A2011-415
Résumé d’auteur What will the new GNSS signals bring to the user of high-precision receivers? This article
provides a brief overview of what users can expect from GNSS systems that are currently
in the modernisation/development stage, looking at new signals and emerging techniques
including coverage of GNSS developments such as GPS, Galileo, GLONASS and
Compass/Beidou. In view of the planned timeframe, what we can do to improve the
robustness of our receivers with a special focus on interference and the upcoming solar
maximum?
Titre
Auteur(s)
GLONASS modernization
URLICHICH (Y.), SUBBOTIN (V.) et al.
_______________________________________________________________________________________
Source
Mots clés
N° notice
Résumé d’auteur
GPS WORLD, vol 22, n° 11, [01/11/2011], pp 34 - 39
CONSTELLATION GLONASS, GLOBAL NAVIGATION SATELLITE SYSTEM, SIGNAL GLONASS
A2011-439
The GLONASS-K satellite, transmitting a CDMA signal in the L3 band, inaugurates a new
era of radionavigation signals for both the Russian system and for international GNSS
interoperability. As demand for high-precision services through duel- or triple- frequency
user equipment increases, GLONASS will come to the forefront. The 2014 GLONASS-K2
satellite will have an FDMA signal in the L1 and L2 and L3. The overall constellation
update will be completed in 2021. Another 2014 launch will fill the Russian SBAS orbit
constellation with three geostationary space vehicles.
Spatial geodesy applications
Titre
Auteur(s)
Source
Mots clés
Simulation study of the influence of the ionospheric layer height in the thin layer
ionospheric model
BRUNINI (C.), CAMILION (E.) et AZPILICUETA (F.)
ALTITUDE, CONTENU TOTAL EN ELECTRONS, DONNEES GNSS, ERREUR SYSTEMATIQUE,
MODELE IONOSPHERIQUE, PROPAGATION IONOSPHERIQUE, SIMULATION, VARIATION
SAISONNIERE
N° notice
A2011-377
Résumé d’auteur This work aims to contribute to the understanding of the influence of the ionospheric layer
height (ILH) on the thin layer ionospheric model (TLIM) used to retrieve ionospheric
information from the GNSS observations. Particular attention is paid to the errors caused
on the estimation of the vertical total electron content (vTEC) and the GNSS satellites
and receivers inter-frequency biases (IFB), by the use of an inappropriate ILH. The work
relies upon numerical simulations performed with an empirical model of the Earth’s
ionosphere: the model is used to create realistic but controlled ionospheric scenarios and
the errors are evaluated after recovering those scenarios with the TLIM. The error
assessment is performed in the Central and the northern part of the South American
continents, a region where large errors are expected due to the combined actions of the
Appleton Anomaly of the ionosphere and the South-Atlantic anomaly of the geomagnetic
field. According to this study, there does not exist a unique ILH that cancels the vTEC
error for the whole region under consideration. The ILH that cancels the regional mean
vTEC error varies with the solar activity and season. The latitude-dependent conversion
error propagates to the parameters of the model used to represent the latitudinal variation
on the vTEC on the ionospheric layer, and to the IFB, when these values are
simultaneously estimated from the observed sTEC. Besides, the ILH that cancels the
regional mean vTEC error is different from the one that cancels the IFB error and the
difference between both ILH varies with the solar activity and season.
Titre
Auteur(s)
Source
Mots clés
Accuracy assessment of the GPS-TEC calibration constants by means of a
simulation technique
CONTE (J.), AZPILICUETA (F.) et BRUNINI (C.)
ANALYSE DIACHRONIQUE, CONTENU TOTAL EN ELECTRONS, GPS EN MODE
DIFFERENTIEL, IONOSPHERE, PROPAGATION IONOSPHERIQUE, RAYONNEMENT
SOLAIRE, VARIATION SAISONNIERE
N° notice
A2011-435
Résumé d’auteur During the last 2 decades, Global Positioning System (GPS) measurements have
become a very important data-source for ionospheric studies. However, it is not a direct
and easy task to obtain accurate ionospheric information from these measurements
because it is necessary to perform a careful estimation of the calibration constants
affecting the GPS observations, the so-called differential code biases (DCBs). In this
paper, the most common approximations used in several GPS calibration methods, e.g.
the La Plata Ionospheric Model (LPIM), are applied to a set of specially computed
synthetic slant Total Electron Content datasets to assess the accuracy of the DCB
estimation in a global scale scenario. These synthetic datasets were generated using a
modified version of the NeQuick model, and have two important features: they show a
realistic temporal and spatial behavior and all a-priori DCBs are set to zero by
construction. Then, after the application of the calibration method the deviations from
_______________________________________________________________________________________
zero of the estimated DCBs are direct indicators of the accuracy of the method. To
evaluate the effect of the solar activity radiation level the analysis was performed for
years 2001 (high solar activity) and 2006 (low solar activity). To take into account
seasonal changes of the ionosphere behavior, the analysis was repeated for three
consecutive days close to each equinox and solstice of every year. Then, a data package
comprising 24 days from approximately 200 IGS permanent stations was processed. In
order to avoid unwanted geomagnetic storms effects, the selected days correspond to
periods of quiet geomagnetic conditions. The most important results of this work are: i)
the estimated DCBs can be affected by errors around +8 TECu for high solar activity and
+3 TECu for low solar activity; and ii) DCB errors present a systematic behavior
depending on the modip coordinate, that is more evident for the positive modip region.
Surveying
Titre
Auteur(s)
Source
Mots clés
State-of-the-art total stations
FERREIRA (R.) et SANTOS (V.)
LEVER TOPOGRAPHIQUE, PRECISION DES DONNEES, SURVEILLANCE D'OUVRAGE,
TACHEOMETRE ELECTRONIQUE, UTILISATEUR
N° notice
A2011-378
Résumé d’auteur In the last few years, the computer revolution has brought about a different approach to
engineering and construction projects. Thanks to automated processes, engineers can
now produce a much higher level of detail and accuracy in their projects. These changes
have significantly increased the level of responsibility within the role of land surveyor in
particular. Surveyors nowadays have more data and information to handle while facing
ever-increasing demands for high-quality topographic products such as construction site
surveys, land ownership and utility management. One of the most important tools
surveyors use is the total station which, having been used for decades merely for the
storage of observations, coordinates and simple mathematical calculations, has recently
evolved into a powerful, integrated field computer. This article will review the newest total
station technologies for performing land surveys, and how they are being used by
surveyors.
Titre
Auteur(s)
Source
Mots clés
GNSS rapidly gains ground
VAN SANTEN (R.) et SIEBRING (R.)
CANALISATION, LEVER SOUTERRAIN, POSITIONNEMENT PAR GNSS, TRAVAUX DE
TERRAIN
N° notice
A2011-379
Résumé d’auteur GNSS, short for Global Navigation Satellite System, is rapidly gaining ground as a tool in
many different areas of work. Dutch contractor A. Hak is one of the companies at the
forefront in terms of incorporating this technology's many applications into its everyday
operations. A prime example of a project in which A. Hak has embraced GNSS is the
construction of the North-South Route, a major gas pipeline that will run from the province
of Groningen in the north to the province of Limburg in the south of The Netherlands. It is
a project that involves a lot of precision digging.
Web geomatics
Titre
Auteur(s)
Source
Mots clés
At the crossroads of geovisualization: How the GeoWeb changes the way of
mapping the world
FISCHER (F.)
CARTOGRAPHIE PAR INTERNET, FONCTIONNALITE, GEOWEB, LOGICIEL DE
CARTOGRAPHIE, MEDIA, POSITIONNEMENT PONCTUEL PRECIS, STYLE
CARTOGRAPHIQUE, VISUALISATION
N° notice
A2011-424
Résumé d’auteur The GeoWeb brings up more and more new ways of mapping the world that put the
traditional distance-based god's eye view of the map on the edge. Thereby the need for a
_______________________________________________________________________________________
changed perspective on mapping from an object resulting of a process to being a
composition of practiced mapping functionalities becomes ever more obvious in order to
explain how they do work in the world. This article give a short overview about the
changing landscape of mapping from the author's point of view.
Titre
Auteur(s)
Source
Mots clés
3D simulation in the cloud
SHIBATA (K.)
GEO:GEOCONNEXION INTERNATIONAL, vol 10, n° 10, [01/10/2011], pp 28 - 29
INFORMATIQUE EN NUAGE, MODELE 3D DE L'ESPACE URBAIN, NAVIGATION, REALITE
VIRTUELLE, SIMULATION, TEMPS REEL
N° notice
A2011-436
Résumé d’éditeur Kota Shibita outlines a new cloud-based tool that gives access to interactive virtual reality
3D city models in real time.
_______________________________________________________________________________________

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