Rabu, 30 September 2009

Community Mapping in Malaysia

Jason W.Y LEE
Department of Multimedia Communications
Faculty of Arts and Social Science
Universiti Tunku Abdul Rahman
wylee@mail.utar.edu.my


Abstract
The availability of open source GIS based software has made it possible for hobbyist access to software that was once accessible by the expert cartographer. However, little attention has been paid to “free’ maps which are often deemed inferior in terms of quality. In this paper, I will review how one particular group of community “mappers”, namely “Malsingmaps” is changing the way maps are distributed in Malaysia. Two methods that are commonly used by community mappers for creating the maps will be demonstrated. The first method is collecting tracks using a handheld GPS unit and second method would be tracing vector images obtained from Google Earth. While the techniques used are not new to the GIS community, the success and power of community mapping is the number of volunteers that contribute to the community map. Community maps are constantly updated with new features added almost every week. Ultimately, community maps cannot replace commercial maps in terms of accuracy but is paving way in making GIS more accessible to the general public.

1.0 Introduction
When the United States military experimented with the Global Positioning System (GPS) in 1978, little did they know that almost 30 years later, the technology can be used from tracking vehicles to trekking for casual hiker. However, accuracy for civilian use was limited as intentional errors between 0 to 100 meters were introduced into public navigational signals by the military to prevent untoward attacks on US interest. This inaccuracy known as Selective Ability (SA) was finally discontinued (The White House, 2000) with an announcement made by then President Bill Clinton on May 1st 2000.

Recent developments in Geographic Information System (GIS) has led the prices of GPS receivers (GPSr) around the world to fall thus making it more accessible to the general public. Mobile devices such as phones and personal digital assistants (PDAs) are also now built-in with GPS capabilities. While GIS technology exists back in 2001, maps for the Asian region, especially South East Asia are often incomplete. GPSr vendors such as Garmin do not offer comprehensive maps for this region except for Singapore (MapSource - City select malaysia, n.d) .This perhaps was one of the main reasons for the low adoption rate of GPS as navigation devices coupled with the high prices of the GPS units in Malaysia.

The availability of open source GIS based software has made it possible for hobbyist access to software that was once for the expert cartographer. However, far too little attention has been paid to “free’ maps which are often deemed inferior in terms of quality. This paper, attempts to demonstrate how one particular group of community “mappers”, namely Malsingmaps is changing the way maps are distributed in Malaysia. A simple proof of concept track that is typically used by this community for creating maps will be reviewed.

2.0 Birth of a community
The lack of proper maps did not deter a group of GPS enthusiast to pursue their interest in this area. As early as mid-2003 a MSN forum was created for GPS enthusiast in Malaysia and Singapore to discuss their interest (Yong, 2005). The lack of proper maps has driven this group of mapping enthusiast to experiment with self mapping. While the growth was slow during the early years, the birth of Malsingmaps has propelled interest in mapping among many GPS enthusiast in Malaysia. Updated maps are released almost every month with the help of other mappers who contribute tracks using their GPSr which will be reviewed later in this paper.

To further improve mapping efficiency, the maps were divided into 9 map tiles covering Peninsular Malaysia (6 tiles), East Malaysia (2 tiles), Singapore (1 tile) covering three countries namely Malaysia, Singapore and Brunei. Several members were selected to be responsible for each tile where updates were to be compiled by them. In the early days, individual map tiles were updated on an irregular basis and maps were only available for Garmin users. However, over the recent years, as the community grew, the maps are now released simultaneously on a variety of format including for the two most popular GPSr format, namely Garmin and Mapking.

2.1 Collaborative Mapping in Malaysia
In order to determine the state of collaborative mapping in Malaysia, Malaysia’s leading community mapping group Malsingmaps was chose. Figure 1 illustrates the map of Klang Valley viewed at various resolutions using Garmin’s Mapsource of the map obtained from Malsingmaps’s official website.


Figure 1: Malsingmap’s Klang Valley Maps on various resolution using Garmin’s Mapsource

At 1km view, the major urban freeways that run along the Klang Valley are clearly visible in dark orange while the tolled highways are visible in dark blue. At the 500 meters, arterials roads are visible in black. Zooming in further reveals various points of interest (POIs) such as bank location, fast food outlets and traffic junctions.

Evidently, the work created by the community is no longer amateur. The maps are fully routable when used with a Gamin GPS unit. While the site was initially created to cater exclusively for Garmin users, the rapid adoption of GPS among Malaysian has lead the group to cater for another set of users, namely Mapking users (Mapking is a software written for the Smartphone and PocketPC platform and is popular in this region).

2.2 Community vs. Commercial Maps
Community maps are by no means perfect. To determine if community maps are on par with commercial maps, a comparison was conducted as illustrated in Figure 2. A visual comparison illustrates the similarities between the roads for both commercial and community map as illustrated in Figure 2. The power of community maps is in the additional POIs such as food stalls and petrol stations contributed by users that do not appear on many commercial maps.


Figure 2: Comparison between Commercial and Community Maps

Closer inspection on the community map reveals that the number of polyline points used are less compared with commercial maps thus making road curves look less smooth and roundabout looking jagged. This can be attributed to the fact that the community maps are drawn from tracks collected from users. However, the purpose of the community maps are for in-car navigation and therefore is not a major issue compared with completeness of the map.

To test the completeness of the community map, 100 roads were selected from around the Klang Valley including newer housing suburbs such as Kota Damansara to older one such as Setapak. A 100% match was found for all the pre-selected roads indicating that the maps were up to date. However, the same test could not be performed for “Commercial Map 1” as it dates back to 2002 and thus does not provide an accurate comparison for this paper.

It should be noted that commercial maps are by no means less superior to community maps. Commercial maps are created with precision and accuracy in mind while community maps are created for their completeness. Completeness in this sense would mean having all the latest roads and important POIs in the base map.

3.0 Authoring Maps
The notion of a group of amateurs creating a complex map of Malaysia could even have been thought as preposterous when not many developed countries around the world have detailed community maps. The availability of GIS freeware and shareware has lowered the barrier of entry to the world of GIS that was once exclusive to the experts. This paper attempts to recreate the two commonly used techniques used by Malsingmaps’s mappers to author these maps. The first method for data collection is done through a handheld GPS unit. The second method uses satellite imagery collected from Google Earth which is then traced to produce tracks.

3.1 Authoring using a GPSr
Using a handheld GPS receiver, a Garmin 60C unit was used to collect tracks around the Klang Valley. To improve trekking accuracy, an external antenna was attached on the roof of the vehicle giving it an average tracking accuracy of ±7 meters. The track logs were set to a 1 second interval to ensure that more road details are captured. The “lock on road” feature was disabled in the Garmin 60C unit to ensure that tracks are not locked to existing roads which renders the tracks useless. When possible, we drove on the far left hand corner of the road at a constant speed.

Once the tracks have been collected, several steps have to be taken before a simple vector map can be produced. Figure 3 illustrates the steps that were taken to produce Garmin’s IMG map format from the tracks that was collected but has no routing capabilities. GPSMapEdit and cGPSmapper are closely integrated thus making the entire conversion process of our proof of concept map from the raw tracks to the IMG Map format in less than 5 minutes.


Figure 3: Authoring using Garmin GPS60C

All the GIS software used in this demonstration such as GPSMapEdit, cGPSmapper and Google Earth are available for free except for Garmin’s Mapsource which comes bundled with the GPS receiver. cGPSmapper is a software that makes it possible to create base maps for Garmin’s close source and proprietary map format called IMG. The developer has created a free version but does not support routing. GPSMapEdit is a visual GPS authoring shareware that provides many advance features in GIS. However, we will mainly use this software to convert our Mapsource data into “Polish format”. Polish format is required by cGPSmapper for converting the collected treks into Garmin readable maps.

3.2 Authoring using Google Earth
The second method in authoring maps is tracing raster images. While this is not a new method for cartographers to create maps, it was not until recently when satellite images became more accessible. This is due to the introduction of Google Earth which has made it possible for almost everyone to obtain high quality satellite imagery for free.

In this paper, an area in the Klang Valley was selected for tracing in Google Earth. It should be noted that the Google Earth images has some offsets that needs to be corrected once the tracing has been done. A screenshot of the selected area is captured with the latitudinal and longitudinal grids enabled for referencing from Google Earth. There are several methods in which the roads can be traced using software such as Garmin’s Mapsource, OziExplorer or GPSMapEdit. Once the roads has been traced, it has to be calibrated approximately 0.00015 west (Mapping with Google earth, 2007). The points traced from the raster image are ready for conversion using a similar process in Figure 3.

4.0 Conclusion
While there is some doubt on the accuracy of community maps, the purpose that the maps were created was simple: to be used as a base map for in-car navigation and recreational purposes. The power of community maps are in the large number of volunteers or mappers as they call themselves who constantly submit updates and corrections back to the community. It is also interesting to note that the community maps also cover many interior areas of Peninsular Malaysia but are limited to major roads.

Undoubtedly, the community maps are not by any means not the most complete maps available. However, in comparison with commercial maps which are very costly, the community maps narrows the digital divide in the GIS community. The efforts taken by the Malsingmap community is indeed commendable. From the birth of the community in 2003, the community is 45,000 members strong and growing by the day as the adoption of GPS increases with inbuilt GPS capabilities in mobile phone handsets

5.0 References
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