Comparisons Between Different Interpolation Techniques

Abstract

Digital terrain models are key tools in land analysis and management as they are directly employable in GIS systems and other specific applications like hydraulic modelling, geotechnical analyses, road planning, telecommunication, and many others. TIN generation, from different kind of measurement techniques, is ruled by specific regulations. Interpolation techniques to compute a regular grid from a TIN, are, instead, still lacking in specific regulations: a unitary and shared methodology has not already been made compulsory in order to be used in cartographic production while generating digital models. Such ambiguity obviously involves non univocal results and can affect precision, which can lead to divergent analyses on the same territory. In the present study different algorithms will be analysed in order to spot an optimal interpolation methodology. The availability of the recent digital model produced by the Regione Piemonte with airborne LIDAR and the presence of sections of testing realized with higher resolutions and the presence of independent digital models on the same territory allow to set a series of analysis with consequent determination of the best methodologies of interpolation. The analysis of the residuals on the test sites allows to calculate the descriptive statistics of the computed values: all the algorithms have furnished interesting results; all the more interesting, notably for dense models, the IDW (Inverse Distance Weighing) algorithm results to give best results in this study case. Moreover, a comparative analysis was carried out by interpolating data at different input point density, with the purpose of highlighting thresholds in input density that may influence the quality reduction of the final output in the interpolation phase.

Spatial Representation of Surface Water Monitoring and Its Assessment Using Geostatistical and Non-Geostatistical Techniques in Gis

“…Spatial interpolation has continued to be an important tool for estimating continuous spatial environmental variables for effective decision making (Ikechukwu, Ebinne, Idorenyin, & Raphael, 2017). Interpolation tools available in geographical information systems are useful and allow the operator to easily perform different kind of elaborations and to display them graphically in order to show the results in a way intelligible also to non-skilled subjects (Garnero & Godone, 2013). Spatial interpolation techniques could be classified in two main groups: (1) mechanical or non-geostatistical technique in which included the Spline method and (2) geostatistical technique in which included Kriging method.…”

Impact of the grid cell size and interpolation methods on earthwork volume calculation

“…Kar nekaj avtorjev je opravilo analizo različnih metod interpolacij na kakovost izdelanega digitalnega modela višin (npr. Gumus in Sen, 2013;Garnero in Godone, 2013;Bater in Coops, 2009;Erdogan, 2009). …”

Credibility of 3D Volume Computation Using GIS for Pit Excavation and Roadway Constructions

“…The Regularized Spline creates a smooth, gradually changing surface. The Tension Spline creates a less smooth surface with values more constrained by the sample data range (Garnero and Godone, 2013).…”