Planetary Remote Sensing and Gis: the Convergence of Software, Techniques

Introduction: Geographic information systems (GIS), and more specifically remote sensing, have been used within the geosciences for well over two decades. In that time, the ability to handle a variety of increasingly voluminous data (both vector and raster) has allowed continued data analysis and exploitation within mainstream GIS. The uptake and use of GIS has not been mirrored within the planetary sciences, partly because of: 1. the origin of much research within astronomy ; 2. lack of digital data; 3. the geo-centric nature of many GIS. The rapid advancement in the quantitative facilities of GIS has seen extensive application on Earth, with more limited use within planetary remote sensing. This abstract briefly explores how we are now seeing a convergence between the use of GIS, application of new techniques and availability of data. Software: GIS software products were historically based around their application domain (e.g. remote sensing). Generically, this meant software oriented around raster (e.g. Clark Labs IDRISI) or vector (e.g. ESRI ARC/INFO) processing. Developments over the last decade has seen the integration of vector and raster data models in to single, unified, products, that can handle large data sets, in different coordinate systems and consistently apply quantitative processing. It is particularly notable that ESRI's ArcMap integrates raster and vector visualisation and processing within one graphical user interface. With the release of version 9.0 ArcMap natively supports coordinate systems of planetry bodies. However commercial GIS are proprietary systems and support of planetry bodies is limited. For example, within ERDAS Imagine there is currently no way that a Martian coordinate system can be added by the user. It is hopeful that work by the Open Geospatial Consortium (OGC) [1] will make the inclusion of coordinate reference systems easier. Quantitative Techniques: One of the benefits brought through the use of mainstream GIS applications is the simplified working environment and implementation of a variety of quantitative techniques. This can involve simple procesing such as contrast enhancements or convolution filtering [2], through to more complex techniques like principal components analysis or fourier transforms [3]. In understanding the evolution of planetary bodies, it is necessary to map the geographic distribution of surface features. A 1:200,000 scale series of topographic maps was planned for the Mars96 mission [4]. The loss of the mission meant that this project was delayed until the