Appropriate technology for low cost geological mapping Methodology The starting point for the project was a manual written by The British Geological Survey, entitled ‘Remote Sensing and image analysis: a practical training manual’ this contained information on guidance for the use of the technology available. This document was then marked up using eXtensible Markup Language (XML). XML is a document processing standard that allows text documents such as the manuals to be encoded with information to allow the retrieval of information as requested by the user. This is a highly useful and relatively new form of designing text formats, and produces files that are easy to generate and easy for a computer to read. (XML) allows text to be encoded with 3 broad types of information.
The text documents for this project were received in a variety of formats including Word documents and RTF files. The software we then used to convert these documents into XML files included WorX-SE, XMLSpy and Omnimark The map based front end for the project was developed using ArcIMS which is a web-based Geographic Information System (GIS) produced by the Environmental System Research Institute (ESRI). It allows the dissemination of GIS data and mapping services via the internet and it was decided that this was the best software for our purposes. ArcIMS has a simple browser interface and provides some of the standard tools present in Desktop GIS systems such as Arcview. Using ArcIMS however means that we are able to serve GIS data across the internet. An example of a standard GIS tool that we have used is the hyperlink function that has enabled us to link between the example satellite images and the countries map so that at the click of a button you are able to view an example image for that country. It was decided that a graphical means of displaying the data would be the most effective way of serving the data we needed across the internet. ArcIMS is easily customisable to fit our needs for the project, for example we have linked from the map using the country codes to retrieve county specific information to further guide the user. This map based front end is used to guide the user to the geographical area in which they are interested. ColdFusion is used for developing powerful web applications using an intuitive tag based scripting language. Examples of its use include the provision of database access and business intelligence solutions. For this project ColdFusion is used as the scripting language that links the ArcIMS software and the XML documents and performs file processing and manipulation. It is also used to create instances of the Microsoft MSXML COM object to allow server-side XSLT processing. XSLT and Omnimark have been used to extract relevant information from the XML data.  Fig. 2: Radarsat Image of the Bartica area illustrating the geological texture of part of the Precambrian basement Case Studies One of the most important concepts of the project is that the methodology must be appropriate in the context of the country’s skill base, infrastructure, geological setting and climate. Therefore 2 case studies were carried out in the contrasting climatic and geographic areas of Guyana and Mongolia. Guyana, in South America, is dominated by tropical rainforest and is obscured by cloud for most of the year where as Mongolia includes a range of climatic zones from arid to temperate. Prior to going into the field suitable remote sensing imagery (both satellite and airborne) was purchased and interpreted for use during the fieldwork. In conjunction with the imagery, GPS and laser ranging devices were used with traditional field mapping techniques to update existing maps and gather new information. To enable the continuation of the methodology after the departure of the BGS staff the local geologists and technicians were supplied with hardware and suitable training.  Fig. 3: Landsat TM image of the Bartica area, Guyana, showing uniform forest-covered Precambrian basement surface |