LandSerf 2.3 User's Guide

1. Introduction

Chapter 1 LandSerf allows you to visualise and perform analysis on spatial data. It is primarily designed to be used with surface and elevation models, but will work with most types of 'GIS' data. It supports rasters, vectors, TINs and other models of elevation. This section includes a summary of command line options and functionality accessible via LandSerf's menus and toolbar.

2. Getting Data In and Out of LandSerf

Chapter 2 In addition to its own file format, LandSerf supports many common GIS and spatial data file formats including rasters and vectors from ArcGIS and GRASS, EDX, Ordnance Survey, US Geological Survey and the visualisation software Terragen, TerraExplorer ('BT' files) and VistaPro. Raster and vector data can be output as GIS files in a range of formats, text for spreadsheets and other software, and web formats including, SVG, KML, VRML and XML. Data may be imported and exported directly from and to Garmin GPS receivers.

3. Creating, Editing and Transforming Data

Chapter 3 New rasters can be created using polynomial expressions or fractal simulation. The spatial boundaries of rasters and vectors can be edited along with other supplementary data. Data can be reprojected between latitude/longitude and a variety of coordinte systems. Rasters can be rectified using on screen selection of ground control points. Vector maps can be digitized on screen. DEMs may be transformed into TINs or contour models. TINs can be transformed to DEMs.

4. Visualising Spatial Data

Chapter 4 Rasters can be visualised as interpolated colour maps, as shaded relief maps, or combined hue-intensity, hue-saturation or blended maps. Vector contours and TINS may be displayed separately or overlaid on rasters. Colour tables associated with raster and vector maps can be edited graphically or numerically.

5. Viewing and Navigating in 3 Dimensions

Chapter 5 LandSerf can view surfaces as if in 3 dimensions. A virtual camera can be 'flown' over a surface in real time to produce more realistic terrain visualisations. Images and vector maps may be draped over the surface to provide contextual information. Various viewing parameters such as haze density, camera field of view, lighting etc, can be altered interactively.

6. Getting Information From Spatial Objects

Chapter 6 Raster and vector header information (title, bounding area, map projection, min/max values etc.), and colour tables may be displayed. Rasters can be interactively queried for attribute values, or multi-scale parameters. Numeric raster cell values can be overlaid onto raster maps for detailed analysis. Univeriate statistics, fractal dimension, variograms, scatterplots and frequency histograms can be calculated from raster data.

7. Performing Analysis on Surfaces

Chapter 7 A variety of surface parameters (slope, aspect, curvature etc.) and surface features (channels, ridges, peaks etc.) may be calculated from elevation models. Analysis can be performed over a range of scales and spatial extents. The degree of scale-dependency can be quantified and visualised.

8. Scripting with LandScript

Chapter 8 LandSerf can also be controlled via script commands using the landuge LandScript. This can be used as a batch or macro languge to mimic GUI controled functions, or as a map algebra calculator. It can also be used for lower level control of rasters and the development of spatial algorithms.