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  • Causes and consequences of error in digital elevation models
  • Bibliography ; Digital elevation model ; Error ; Methodology ; Model ; Physical geography ; Typology
  • This paper reviews research on the understanding, modelling and propagation of error in DEMs, with the aim of presenting a comprehensive statement of the issues surrounding these topics : sources of error in DEMs, error models, error propagation
  • , visualization of error, error correction and fitness for use.
  • Error propagation in quantitative spatial modelling. Applications in Geographical Information Systems
  • Error ; Geographical information system ; Modelling ; Spatial statistics ; Statistics
  • This book deals with the different aspects of the problem of error and error propagation in GIS. It is restricted however to the propagation of quantitative attribute errors in logical, empirical and conceptual models that are used in, or with GIS
  • . This means that neither positional error nor the propagation of qualitative or categorical errors are dealt with. - (AGD)
  • Evaluation of model performance when the observed data are subject to error
  • This paper addresses the effect of observational errors on the mean squared error, the mean bias error and the mean absolute deviation through the derivation of a statistical framework and Monte Carlo simulation. Examination of scaled differences
  • between modelled and observed values, where the differences are divided by the estimated standard errors of the observed values, is suggested as a diagnostic tool for determining whether random observational errors are significant.
  • The empirical determination of house prices, error correction mechanisms and the correction of errors. (Followed by the reply of J. G. Nellis)
  • The encoding-error model of pathway completion without vision
  • Distance ; Error ; Model ; Navigation ; Route ; Simulation
  • The model accounts for errors in short-cutting to complete a triangular pathway by individuals deprived of visual input. It assumes that systematic error arises from components of navigation concerned with encoding an internal representation
  • Variations in multiscale curvature distribution and signatures of LiDAR DTM errors
  • Digital elevation model ; Error ; Geomorphometry ; LiDAR ; Model ; Remote sensing ; Statistical analysis
  • Análisis estadístico ; Error ; Geomorfometría ; LiDAR ; Modelo ; Modelo numérico de terreno ; Teledetección
  • This work analyzes Minimum Curvature distributions to identify the statistical signature of 2 types of LiDAR-DTM errors (outliers and striping artifacts) in the derived estimates, rather than morphology itself. The analysis shows the importance
  • of modeling these errors correctly, in relation to the scale of analysis and DTM resolution, in order to have reliable curvature estimates. Nine DTMs of different morphological areas are considered, and grouped into a training dataset (without errors
  • ) and a test dataset (with errors). This study shows that the curvature distributions are impacted upon differently by striping artifacts and outliers, and that these are clearly distinguishable from the signal of morphological features : a scale-dependent
  • change in curvature distribution can therefore be interpreted as the signature of these specific errors, rather than morphology.
  • Point-counting technique for fission-track dating of tephra glass shards, and its relative standard error
  • Dating ; Error ; Geochronology ; Methodology ; New Zealand ; North Island ; Quaternary ; Statistics ; Tephrochronology
  • In this work, the AA. consider a procedure called point counting that significantly reduces the counting times, but also introduces an additional source of error. They study this additional error and provide a simple formula for estimating
  • the relative standard error of a fission-track density determined by the point-counting technique. In conclusion, this study has shown that, especially for very low track densities which are typical of Quaternary tephra, the point-counting technique can
  • Measuring neighbourhood spatial accessibility to urban amenities : does aggregation error matter ?
  • Accessibility ; Aggregation ; Error ; Residential environment ; Statistics ; Urban area ; Urban district ; Urban infrastructure
  • Aggregation error arises when a single point is used to represent a neighbourhood. The spatial accessibility to three types of recreational amenities in Edmonton, is used to assess whether aggregation error affects the measures. Exploratory spatial
  • data analysis techniques are used to examine aggregation-error effects on spatial accessibility.
  • Estimation and propagation of error in measurements of river channel movement from aerial imagery
  • Aerial photography ; Channel geometry ; Data processing ; Error ; Methodology ; Photointerpretation ; Stream
  • Detailed methods are presented for the estimation of errors in quantifying channel migration rates that can be easily applied to GIS-based analysis of planform change. In addition, the impact of relaxing assumptions regarding error independence
  • between image dates and systematic registration errors is presented and discussed.
  • Errors in regional nonsurvey input-output models: analytical and simulation results
  • Climatology ; Error ; Pluviometry ; Precipitation ; Slovenia
  • Climatología ; Error ; Eslovenia ; Pluviometría ; Precipitación
  • Precipitation data are important for hydrology, climatology, geography etc. Discussed are systematic errors that occur at the standard method of precipitation measurements using rain gauges. The components of the systematic error are related
  • Ring permeametry : design, operation and error analysis
  • Error ; Methodology ; Permeability ; Reliability ; Soil ; Soil properties
  • This paper describes an alternative ex situ core permeametry technique that is field based. The potential sources of precision and bias error within the method are quantified and their effect on the uncertainty of permeability estimates
  • Reducing errors in rainfall estimates through rain gauge location
  • Facility location models are examined as a framework for generating rain gauge networks designed to reduce errors in mean areal precipitation.
  • Error ; Information ; Location ; Simulation ; Spatial analysis ; Spatial statistics ; Statistics
  • The AA. propose a statistical model for incorporating location error into spatial data analysis. They investigate the effect of location error on the spatial lag, the covariance function, and optimal spatial linear prediction.
  • The effect of common sources of regression error on benefit estimates
  • The AA. explore how the assumptions about sources of error influence estimates of recreation benefits.
  • Data base ; Error ; Geographical information system ; Numerical model ; Photogrammetry ; Simulation ; Slope ; Slope gradient ; Spatial analysis ; Statistics
  • The AA. show that errors in slope and aspect depend on the spatial structure of digital elevation models (DEM) errors. They propose a general-purpose model of DEM errors in which a spatially autoregressive random field is added as a disturbance term
  • to elevations. In addition, they propose a general procedure for propagating such errors through GIS operations. In the absence of explicit information on the spatial structure of DEM errors, they demonstrate the potential utility of a worst-case analysis
  • . A series of simulations are used to make general observations about the nature and severity of slope and aspect errors.
  • Using sediment fingerprints to assess sediment-budget errors, North Halawa Valley, Oahu, Hawai, 1991-92
  • Aeolian features ; Aerosol ; Error ; Hawaii ; Methodology ; Sediment budget ; Suspended load ; Tropical zone ; Watershed
  • Reliable estimates of sediment-budget errors are important for interpreting sediment-budget results. The AA. modified the sediment fingerprinting approach to qualitatively evaluate compensating errors in an annual (1991) fine sediment budget
  • imbalances provide a measure of compensating errors in the sediment budget.
  • Predicting ordinary kriging errors caused by surface roughness and dissectivity
  • The aim of this paper is to determine the association of ordinary kriging (OK) estimated errors with the local variability of surface roughness, and to analyse the suitability of probabilistic models for predicting the magnitude of OK errors from
  • surface parameters. The results underscore the importance of the role of the local diversity of relief properties in increasing or decreasing the magnitude of interpolation errors. The newly developed dissectivity parameters provide useful information
  • for terrain analysis. The study also provides constructive guides to understanding the local variation of interpolation errors and their dependence on surface dissectivity.
  • Reporting error in the census and surveys
  • Enquiry ; Error ; Great Britain ; Methodology ; Population ; Population census ; United States of America
  • Investigating DEM error patterns by directional variograms and Fourier analysis
  • Error ; Methodology ; Relief ; Spatial autocorrelation ; Spatial structure ; Statistics ; Topography ; Variogram