Although open source softwares (OSS) for GIS and Remote Sensing are rapidly expanding and improving in the global context, there has been uncertainty at higher education institutions in developing countries, such as the department of forestry (Dfo) at Unitech, Papua New Guinea (PNG), regarding appropriate GIS softwares and hardware to acquire and use for teaching and research purposes. The paper briefly describes the characteristics of some mature OSS and discusses their main capabilities, advantages and disadvantages. Their adoption in the Dfo curricula may be advantageous in the long term, considering issues of learning curve steepness, versatility, affordability, effectiveness, and documentation available on them.
Open Source Software; GIS Software; Forestry Education
GIS is a key technology for developing countries in domains such as environmental protection, urban management, agricultural production, deforestation mapping, public health assessment, and socioeconomic measurements. It is defined as a system of software components that maintain a spatially aware database, provides analytical tools that enable spatial queries of the database, allows the association of locations with imported graphical data, and provides graphical and tabular output. The open source components are distinguished by the availability of source code under free and/or open source software licences, by access to infrastructures such as version control systems for source code, bug trackers, mailing lists and at partly organised communities, and by the documentation of external dependencies in the build and install system (
costs and of promoting indigenous technological development.
Large scale environmental and socio-economic applications compel OSS to include significant spatial analysis capacities to meet the needs of end-users [
Most third year students at Dfo understand the use and usefulness of maps and basic surveying tools, often needed when they are employed either by PNG Forest Authority, NGOs, logging companies or private projects; in many cases at remote areas with the challenge to solve practical problems in situ. Most of them are also financially able to purchase a personal computer, have intermediate computer skills, and can access the internet. However, besides the high acquisition cost of latest digital data, most areas in the country are of difficult access, and inter institutional coordinations to implement the highly publisized Reducing Emissions from Deforestation and forest Degradation (REDD) mechanism, negotiated since 2005 by the United Nations Framework Convention on Climate Change (UNFCCC), are still weak. Only few PCs at the Dfo are in working status (for GIS), and the license for propietary GIS software seldom can be renewed on time. Even though there are no preliminary subjects on cartography, the one on GIS has to be completed in 13 weeks. Other inconveniences are frequent cut downs of power supply, narrow internet bandwidth connection, low graduates continuity rate on GIS projects (less than 10% of them), and budget shortage to upgrade labs and equipment.
Users are concerned on the long-term maintenance of their files and applications, the sustainability of OSS projects, and costs of data conversion (commercial GIS products use proprietary data formats) [
New projects are appearing in the internet with enhanced capabilities and new applications with different levels of complexity (
Released in the 1980s at the Construction Engineering Research Laboratory (CERL) of the United States Army for military applications; evolving into one of the most comprehensive, general purpose OSS. GRASS
(http://grass.osgeo.org) is a raster/vector GIS combined with integrated image processing and data visualization
subsystems. It includes hundreds of modules for management, processing, analysis and visualization of geo-referenced, spatial data. GRASS uses both an intuitive graphical user interface as well as command line syntax for ease of operations. Approximately 200 of the modules that are available in GRASS GIS are integrated in pull down menus [
Conceived by Gary Sherman [
graphical features across the web using platform-independent calls. The fusion with the uDig software project is ongoing, adding 3D visualization and further GIS analytical capabilities to uDig. There are over 100,000 Qgis users worldwide [
MapServer creates map images from spatial information stored in digital format. It can handle both vector and raster data and render over 20 vector data formats, including shapefiles, PostGIS and ArcSDE geometries, OPeNDAP, Arc/Info coverages, and Census TIGER files [
It was initially developed and distributed by ITC Enschede (International Institute for Geo-Information Science and Earth Observation) in the Netherlands two decades ago for use by its researchers and students [
Bangladesh, using data of the April 1991 cyclone. The project produced several maps of the expected number of casualties per village and population category caused by cyclone flood events with return periods of 5, 10, 20 and 50 years. Prior to this, maps of the flood depth per return period, population density and population vulnerability to flooding have to be made. For the calculation of the flood depths, a DTM and a linear flood-decay model were used.
PostGIS is a spatial database extender for PostgreSQL object-relational database. It adds support for geographic objects allowing location queries to be run in the simple features of SQL specification from the Open Geospatial Consortium (OGC) [
GeoTools is a Java library for geographic information system (GIS) applications to be used by programmers building spatial data applications, rather than by end users looking to make maps. It is now in its second version and is used as the base of several well known OSS products including GeoServer, uDig, and GeoVISTA studio [
The User Friendly Desktop (uDig) Internet GIS, designed by Refractions Framework Research (http://udig.refractions.net) is a frequent framework for building other GIS platforms and applications like DIVA-GIS, and the Distant Early Warning System for Tsunamis (DEWS). It provides viewing and editing for a variety of data formats, including the usual file-based layers (shapefiles and rasters), PostGIS layers, WMS, WFS, Oracle Spatial, and DB2 that cover most of common data needs (
An open-source collection of computer software tools for processing and displaying xy and xyz datasets, including rasterisation, filtering and other image processing operations, and various kinds of map projections. Written in C, It was originally developed in 1988 by Paul Wessel and Walter H. F. Smith and is currently hosted
at the University of Hawaii. The letters GMT originally stand for Gravity, Magnetism and Topography, the three basic types of geophysical data as most of its users are geoscientists. Besides its strong support for the visualisation of geographic data sets, the software includes tools for processing and manipulating multi-dimensional datasets.
It has of 60 specialized map making commands which output to publication-quality PostScript format making possible to fill the gap in hard copy map production which has troubled GRASS users for long [
GMT stores 2-D grids as COARDS-compliant netCDF files and comes with a comprehensive collection of free GIS data, such as coast lines, rivers, political borders and coordinates of other geographic objects. Users convert further data (like satellite imagery and digital elevation models) from other sources and import them. GMT stores the resulting maps and diagrams in PostScript (PS) or Encapsulated PostScript (EPS) format. Users operate the system from the command line enabling scripting and the automation of routine tasks. More or less comprehensive graphic user interfaces are available from third parties, as well as web applications, bringing the system’s functionality online.
It was designed to meet Brazil’s challenges on natural and human resources monitoring. It operates as a seamless geographical data base with a large volume of data, without being limited by tiling schemes, scale and projection [
The design goal for TerraLib is to support large-scale applications using socio-economic and environmental data. TerraLib supports coding of geographical applications using spatial databases, and stores data in different database management systems including MySQL and PostgreSQL. Its vector data model complies with Open Geospatial Consortium (OGC) standards. It handles spatio-temporal data types (events, moving objects, cell spaces, modifiable objects) and allows spatial, temporal, and attribute queries on the database [
Is a GIS tool designed to be a multi-user editor of geographic vectorial data stored in a TerraLib model database. It engages land use and land cover classification tools as well as spatial operations between vector data, allowing transitions analysis among other applications. TerraAmazon keeps work time records for project control. It’s functionalities are extensible through plugins, such as the already existing TerraImage (PDI) and TerraPrint (plotting). The assignment of a date to this geometry establishes the creation of a scenario. It is possible to create many scenarios for the same geometry by assigning different dates to it. TerraAmazon has two user levels: Administrator and Operator [
A GIS originally developed at Goettingen University in Germany. The core development and software maintenance team has moved to the University of Hamburg, Germany. Version 2.0 in 2007 was the second major release of the SAGA program. The interim version 2.0.5, July 2010, is an upgrade. SAGA is a hybrid GIS with emphasis on grid (raster) functions. Vector data layers as shapes data layers. The shapes format is a non-topological vector format developed by the Environmental Systems Research Institute (ESRI). ESRI allows the shapes format to be used in noncommercial software. Vector files (and Point Cloud data layers) used with SAGA are in the shapes format.
The Application Programming Interface (API) as well as module libraries are Dynamic Link Libraries (DLL) not independ executables, and are accessed through a front end program. A Graphical User Interface (GUI) is one of the two SAGA front ends; it is a Windows-like implementation that allows to control the system [
The parameter dialog of the modules is split into a Data Objects section (further subdivided into grids, shapes and tables) for input and output datasets and an Options section with further parameters required by the module [