- TRACE QUANTUM GIS HOW TO
- TRACE QUANTUM GIS PORTABLE
- TRACE QUANTUM GIS SOFTWARE
GRASS: Modernized GIS manager and WMS support gis.m: Michael Barton, Cedric Shock r.in.wms: Sören Gebbert & Jachym Cepicky. TRACE QUANTUM GIS HOW TO
How to use GRASS GIS? GRASS startup screen. Geodetic Datums of Gauss-Boaga Geodetic datum: “peninsular datum” 'Monte Mario to WGS 84 (4)','Position Vector 7-param. Italy: Gauss-Boaga Fuso Ovest ESRI PRJ-File for Fuso Ovest (g.proj -w in GRASS) PROJCS], PRIMEM, UNIT], PROJECTION, PARAMETER, PARAMETER, PARAMETER, PARAMETER, PARAMETER, UNIT] EPSG codes: Gauss-Boaga/Monte Mario 1: EPSG 26591 Gauss-Boaga/Monte Mario 2: EPSG 26592. Italy: Gauss-Boaga Coordinate System Gauss-Boaga Transverse Mercator projection 2 zones ( fuso Ovest, Est ) with a width of 6✣0' longitude Each zone is an own projection! False easting: Fuso Ovest: 1500000m (1500km) Fuso Est: 2520000m (2520km) False northing: 0m Scale along meridian: 0.9996 – secante case, not tangent case Ellipsoid: international (Hayford 1909, also called International 1924) Geodetic datum : Rome 1940 (3 national datums local datums to buy from IGM). versus Vector Topology - points, centroids, lines, boundaries - in topology centroid and boundary form an area - single boundaries for adjacent areas Advantage: - less maintenance, high quality Disadvantage: - slower computations Switzerland Original Pruned each boundary is a single line, divided by two polygons (UTM32N projection) Map generalized with v.clean “prune” algorithm in topological GIS GRASS OGC Simple Features versus Vector Topology. 
points, lines, polygons - replicated boundaries for adjacent areas Advantage: - faster computations Disadvantage: - extra work for data maintenance - in this example the duplicated boundaries are causing troubles Switzerland slivers Map generalized with Douglas-Peucker algorithm in non-topological GIS gaps (Latitude-longitude) OGC Simple Features versus Vector Topology Simple Features.Vector data model Vector geometry types Point Centroid Line Boundary Area (boundary + centroid) face (3D area) Geometry is true 3D: x, y, z Line Faces not in all GIS! Node Node Vertex Vertex Segment Segment Segment Node Boundary Vertex Vertex Vertex Vertex Centroid Area.
Raster data model Raster geometry cell matrix with coordinates resolution: cell width / height (can be in kilometers, meters, degree etc.) y resolution x resolution. image processing 3D Voxel data for volumetric data 2D/3D Vector data with topology Multidimensional points data Orthophoto Distances Vector TIN 3D Vector buildings Voxel Spatial Data Types Supported Spatial Data Types 2D Raster data incl. 
TRACE QUANTUM GIS PORTABLE
GRASS GIS Brief Introduction Developed since 1984, always Open Source, since 1999 under GNU GPL Written in C programming language, portable code (multi-OS, 32/64bit) International development team, since 2001 coordinated at ITC-irst GRASS master Web site: GNU/Linux MacOSX MS-Windows iPAQ.Neteler neteler at ITC-irst, Povo (Trento), Italy (Document revised November 2006)
TRACE QUANTUM GIS SOFTWARE
The GRASS GIS software GIS Seminar Politecnico di Milano Polo Regionale di Como M. The GRASS GIS software (with QGIS) - GIS Seminar
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