Page 1 of 1  David Jonas Project Manager, South East Asia, AAM Hatch d.jonas@aamhatch.com.au Malaysia is well-placed as to allow recent advances in technology giving impetus to the Geographical Information Systems that currently exist in the country. There are numerous GI Systems in Malaysian Government departments, large corporations and smaller consultancies. These systems could serve their masters better when they are fuelled with the most important component of a GIS: appropriate data. Developments in survey technology now allow datasets to be collected which previously were simply too expensive or time consuming to be considered. The extent and resolution of these new datasets range from millimetres to metres. Highly precise equipment can define complex structures to millime- tre accuracy; highly efficient techniques can capture and present a whole country on a simple desktop PC. GIS managers no longer have to rely on existing "hand-me-down" datasets, they can commission the data built for their own purposes. What used to be the weakest link in the GIS chain, "Data In", can now become a sound foundation for the entire system. Developments in technology require the need to balance the enthusiasm associated with enabling new technology with a reflection on previous learning. With technology, comes a word of ‘encouragement’ and note of ‘reflection’. Encouragement: Current professionals in spatial sciences need to embrace these new technologies. Technology by itself offers new tools to apply known principles. A spatial science professional is well versed in the fundamental principles of geometry, redundancy and error theory. Every development in survey technology in the last century has served to reinforce the need to adhere to these fundamental sciences. As the implementation of geometry and mensuration has escaped from the survey department to the wider community, the need for a sound understanding of geometry, redundancy and errors has increased. The opportunities for professionals have opened up markedly. Twenty years ago, the spatial science professional's main clients came from engineering departments. Nowadays, their clients are from industries as diverse as taxi operators, marketing executives, economists, conservationists and managers.  Fig. 1 Digital image with 5cm pixels GPS is the best example of this trend. Ten years ago, GPS was touted as being the death of the spatial professional as any layperson could position himself with simple held-held devices. In reality, the widespread adoption of GPS has lead the way in introducing the benefits of spatial data to the whole community. Reflection: The reflection comes as an extension to the Encouragement: Do not adopt technology for technology's sake. Whilst technology offers a new range of tools for the toolbox and allows one to measure features not previously possible, as in any craft, one must select the most appropriate tool for the task. The Malaysian community needs professionals to review the task at hand, assess the tools available, and adopt the technology which best serves the client's needs. THE TECHNOLOGY One of the interesting characteristics of recent developments is that most technologies are converging. Total stations are now available with built-in GPS receivers. Terrestrial Laser Scanners (TLS) now record responses from the visible spectrum so that they can reconstruct a "photograph" of the target object. What is a TLS if not a "multi-measurement, automatic total station"? This convergence of technology supports the earlier premise that these new tools are merely manifestations of the fundamental principles of measurement. Whether the resection comes down from GPS satellites, individually by total station observations, or en masse from terrestrial laser returns is immaterial, as long as the professional is applying it. Recognising that recent advances are all intertwined, the following description of the technology available to fuel Malaysian GISs is presented alphabetically. Bathymetric LiDAR - Light Detection and Ranging (LiDAR) has been around for a while (see below), but Bathymetric LiDAR is now offering surface definition to those concerned with what is happening beneath the water surface. Using different wavelength lasers from standard LiDAR systems, the bathymetric lasers will penetrate water from 0 to 50m in depth, depending upon the clarity of the water. Penetration depths are measured in "secchi depth", i.e. lower a 20cm diameter disk (with alternate black and white quadrants) into water; the depth where the disk disappears from sight is equivalent to one secchi depth. Bathymetric LiDAR systems can penetrate two to three times this secchi depth. Using this definition, coral quays off the islands off Kota Kinabalu will have good penetration, whilst the laser would not penetrate the muddy waters of the Klang River beyond a few decimetres. There are two commercial Bathymetric LiDAR systems now available in the commercial world; they are achieving survey accuracies of IHO order 1 (0.25m vertical and 2.5m horizontal). They offer typical survey coverage of 350km2 per day, achieving in one day what conventional ships cover in a week.  Fig. 2 JUPEM’s CORS locations Digital Aerial Cameras - Aerial survey cameras have remained essentially unchanged since the 1930's. Certainly, lenses and films have evolved over time and Forward Motion Compensation and stabilised mounts have aided low-level photography. However, the quantum leap forward arrived in the last couple of years with Digital Aerial Cameras. This revolution in survey is equivalent to the handheld digital cameras one now sees in use atop KL Tower or around Penang Island resorts. Digital Aerial Cameras incorporate and integrate all of the recent developments of aerial cameras, but replace the filmrecording medium with high resolution, multispectral digital sensors.
Distributed Datasets - Software is now available which permits GIS users to access multiple datasets spread across the world with remarkable ease. Imagine a TNB repair crew using Microsoft Explorer in a remote part of Terengganu to call up satellite imagery stored in the US, and overlaying it with an electricity network diagram held in Cyberjaya, the JKR Road center line diagram to provide access details and JUPEM's cadastral layer to advise who owns the property in difficulty. Software such as CubeWerx utilising OpenGIS standards provides the seamless interface to serve datasets stored in different locations using everyday Internet Explorer browsing software or within popular GIS displays. See http://www. cubewerx.com.au/ozdemo13a.html for but one example of distributed datasets; this sample shows several layers, all stored on different servers in different organizations. Google Earth - Headline examples of Distributed Datasets are Google Earth, and its Microsoft response, Virtual Earth. Google Earth has propelled the community's awareness and interest in spatial data to new levels. Professionals would do well to direct clients to this site. Encourage them to type "Kuala Lumpur, Malaysia" into the Fly To window; zoom into KLCC to see the cars in the car park; explain that the long shadows to the West (and few cars on the road) suggest the image was taken early morning. This promotes the concept that technology is introducing new clients to the power of spatial data. Professionals of spatial sciences can also take advantages of Google Earth. Even the free viewer accepts locally- held GIS datasets added to the display by way of Keyhole Markup Language (KML). GPS - Global Positioning System (GPS) has definitely "escaped" from the survey department and embraced by the wider community. Recent events relevant to the Malaysian GIS community include: CORS Networks - Continuously Operating Reference Stations (CORS) are now available in Malaysia, with JUPEM offering a network of stations across the country. The "Malaysian Active GPS System (MASS)" offers a reliable, inexpensive and well-distributed GPS infrastructure for the Malaysian community. With permanent base station data available, surveyors can use half the number of GPS receivers, or double their rate of progress, for many projects. Galileo - the first Galileo satellite was launched late last year. When operational in 2008, the European community will have 30 satellites, complementing the GPS constellation of 27. Equipment manufacturers are already designing receivers to log data from both GPS and Galileo satellites; the software to process from different constellations has been around for some time. Effectively doubling the number of satellites available will not significantly improve the accuracy of Satellite positioning, but it will dramatically increase the redundancy to improve the reliability of positions and reduce the blackspots and poor geometry situations. This will be particularly useful for operations in obscured areas such as cityscapes and mine sites. The Russian constellation Glonass is planning to have 18 of their satellites in orbit by 2007. Multi-base station reduction - Accurate differential GPS has always relied on computing the errors at one GPS receiver (the "rover"), based upon the computed errors at a second receiver running over a known mark (the "base"). This assumption meant that the rover had to be "reasonably" close to the base, otherwise the assumption that the errors at the base apply to the rover would break down. Rover-base separations range from 5km to 50km for accurate work, or up to a couple of hundred kilometres if less accurate pseudo-range solutions were acceptable. Multi-base station reduction software is now available to compute the errors at the rover based upon a number of surrounding base stations. This allows accurate positioning of the rover at distances of many hundreds of kilometres by interpolating the errors from numerous surrounding bases. The concept of multi-base station reduction complements the use of CORS networks. Centimetre accuracy is now possible with a single receiver at Kuala Lipis using JUPEM stations at Ipoh, Kuantan and KL.  Fig. 3 LiDAR data capturing LiDAR - LiDAR (also known as "Airborne Laser Scanning") was commercialised in 1994 but is still a technology yet to be embraced and exploited in Malaysia. LiDAR is a survey technology that uses a measuring laser from an aircraft (fixed wing or helicopter). The measuring laser reflects from the ground, trees, buildings and powerlines below to define the shape of the ground and everything on it to an accuracy of 15cm. Measurements can be taken every metre or more if required. The measuring laser can penetrate gaps in the vegetation to record the ground below, which makes it eminently suited to the tropical regions of Malaysia. The high-density data allows good definition of complex landforms such as cityscapes, flat areas such as mudflats or narrow features such as power transmission lines. The efficiencies of automatic data collection from an aircraft revolutionises broad-acre mapping for flood mapping, infrastructure design and power line maintenance - all applications with relevance in Malaysia at the time of the Ninth Malaysian Plan (RM9). Satellite Imagery - The commercial availability, accuracy, and accessibility of sub-meter satellite imagery from the IKONOS and QuickBird satellites have redefined the market for remote-sensing products in Malaysia. Combined with the 2.5m offering from SPOT-5; consumers now have access to a range of imaging platforms to meet specific requirements. This growing user-base includes plantation, forestry, engineering, town planning, environmental monitoring, and security / surveillance operations. The industry is well served by a growing base of local consultants offering products and services tailored to varied requirements. Imagery can be ordered from archive, or the satellite can be tasked to capture specific site. Archive coverage is driven both by user orders and the priorities of the satellite providers. Archive availability and persistent cloud cover for new orders may limit the uptake of high-resolution imagery. A quick examination of the available high-resolution image archives shows South East Asia and Central America as the most difficult regions to acquire acceptable (less than 20% cloud cover) new imagery on order. Archive coverage over Malaysia is patchy, but growing by the week, with most major urban centers covered, and many transportation routes linking these centers available at high-tomedium resolutions. Coastal regions are targeted due to their sensitivity.
Terrestrial Laser Scanning - The ground-based version of LiDAR, Terrestrial Laser Scanning (TLS) involves a revolving laser on a tripod and measuring millions of 3D points at accuracies and point separation at millimetre levels. This technology has particular application to support Malaysia's growing industrial and energy sectors. We now have a method to measure the precise location, size and shape of complex structures such as oil refineries and processing plants. In one case study the author was involved in an expansion to a major processing plant that involved 521 tie-ins. The new components were made offsite and, when fitted to the existing works, all bar 3 did not fit perfectly (and those three were due to design changes, not survey error). Other relevant applications include deformation measurement, façade mapping for historical buildings, dam-deformation measuring and any other complex or deformed feature definition. Thermal Imagery - Heat can be a informative parameter and technology now exists to accurately measure and analyse thermal anomalies. Applications relevant to the Malaysian economy are: Electricity hotspots - where thermal hotspots indicate weaknesses in the asset, locate electricity losses and indicate potential failures Geothermal areas - where mapping thermal anomalies in structures or landforms help to indicate structural weaknesses and potential landslips Pipeline defects - where leaking water, oil or gas can be detected rapidly from aircraft- mounted thermal sensors THREE DIMENSIONAL VISUALIZATIONS The GIS community has long been searching for more effective methods of presenting three-dimensional information to the wider community. Soft- ware is now available to present reality and design in readily recognisable formats. Such software can be presented with position only, position and texture, or position and imagery, with each step increasing the effort required and the reality level. Many packages allow visualisations incorporating pre-defined flight paths; others reformat the data into 3D models and offer display software to allow the user to zoom and pan to see areas of interest, drawing on threedimensional data directly from GIS databases Video Mapping - Video imagery provides a wealth of visual information in a form with which everyone is familiar. The GIS community has not readily adopted video because there was no efficient means to spatially reference the imagery until now. Packages are now available which embed the GPS position of every frame into the data-track of the digital video file. Add-ons to ArcView, Mapinfo or stand-alone viewers can then read, display and position the video in its correct spatial location. This becomes a very valuable tool, especially for those outside of the GIS community and are not comfortable reading maps or cannot wait for aerial photographs to be mosaiced. CLOSING COMMENTS Although not claiming to be an exhaustive coverage, the above presentation has described some of the technologies available to fuel the GIS systems located throughout Malaysia. Some of these techniques are embraced or standard procedure elsewhere, others are just coming on-line. All are available to the Malaysian GIS community now. These techniques should be considered and balanced with existing techniques. Used appropriately, new enabling technologies offer significant cost savings and will help stretch the data-collection further. As with all new developments, they call for a fresh approach to implementation. Existing methods might be most economically performed in 10km components; new methods require a review of this. Alternative techniques may be more economically collected in 100km components, offering faster, more detailed and more accurate datasets for significantly less. Technical advances offer significant cost savings and performance improvement if used appropriately. Therein lies the challenge for the whole GIS community. There are plenty of others who have gone before you and are willing to share their experiences and insights.
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