pemetaan digital; peta onlie

1. Web Mapping
By Musnanda Satar

2. Pengertian
• Web mapping is the process of designing, implementing,
generating and delivering maps on the World Wide Web
and its product. While web mapping primarily deals with
technological issues, web cartography additionally studies
theoretic aspects: the use of web maps, the evaluation and
optimization of techniques and workflows, the usability of
web maps, social aspects, and more. Web GIS is similar to
web mapping but with an emphasis on analysis, processing
of project specific geodata and exploratory aspects.[1]
Often the terms web GIS and web mapping are used
synonymously, even if they don't mean exactly the same. In
fact, the border between web maps and web GIS is blurry.
Web maps are often a presentation media in web GIS and
web maps are increasingly gaining analytical capabilities.

3. Perkembangan Web Maping
• The advent of web mapping can be regarded as a major
new trend in cartography. Previously, cartography was
restricted to a few companies, institutes and mapping
agencies, requiring expensive and complex hardware and
software as well as skilled cartographers and geomatics
engineers. With the rise of web mapping, a range of data
and technology was born - from free data generated by
OpenStreetMap to proprietary datasets owned by Navteq,
Google, and others. A range of free software to generate
maps has also been generated, alongside proprietary tools
like ArcGIS. As a result, the barrier to entry for creating
maps on the web has shifted from that of the paper atlas
and other traditional cartography.

4. Tipe Web Mapping
• Analytic web maps
These web maps offer GIS analysis, either with geodata provided, or with geodata uploaded by the map user. As already mentioned, the borderline
between analytic web maps and web GIS is blurry. Often, parts of the analysis are carried out by a serverside GIS and the client displays the result of the
analysis. As web clients gain more and more capabilities, this task sharing may gradually shift.
• Animated web maps
Animated Maps show changes in the map over time by animating one of the graphical or temporal variables. Various data and multimedia formats and
technologies allow the display of animated web maps: SVG, Adobe Flash, Java, QuickTime, etc., also with varying degrees of interaction. Examples for
animated web maps are weather maps, maps displaying dynamic natural or other phenomena (such as water currents, wind patterns, traffic flow, trade
flow, communication patterns,social studies projects, and for college life, etc.).
• Collaborative web maps
Collaborative maps are still new, immature and complex to implement, but show a lot of potential. The method parallels theWikipedia project where
various people collaborate to create and improve maps on the web. Technically, an application allowing simultaneous editing across the web would have to
ensure that geometric features being edited by one person are locked, so they can't be edited by other persons at the same time. Also, a minimal quality
check would have to be made, before data goes public. Some collaborative map projects:
• Dynamically created web maps
These maps are created on demand each time the user reloads the webpages, often from dynamic data sources, such as databases. The webserver
generates the map using a web map server or a self written software. Bhoosampada by Indian Space Research Organizations.
• Online atlases
Atlas projects often went through a renaissance when they made a transition to a web based project. In the past, atlas projects often suffered from
expensive map production, small circulation and limited audience. Updates were expensive to produce and took a long time until they hit the public. Many
atlas projects, after moving to the web, can now reach a wider audience, produce cheaper, provide a larger number of maps and map types and integrate
with and benefit from other web resources. Some atlases even ceased their printed editions after going online, sometimes offering printing on demand
features from the online edition. Some atlases (primarily from North America) also offer raw data downloads of the underlying geospatial data sources.
• Realtime web maps
Realtime maps show the situation of a phenomenon in close to realtime (only a few seconds or minutes delay). Data is collected by sensors and the maps
are generated or updated at regular intervals or immediately on demand. Examples are weather maps, traffic maps or vehicle monitoring systems.
• Static web maps
Static web pages are view only with no animation and interactivity. They are only created once, often manually and infrequently updated. Typical graphics
formats for static web maps are PNG, JPEG, GIF, or TIFF (e.g., drg) for raster files, SVG, PDF or SWF for vector files. Often, these maps are scanned paper
maps and had not been designed as screen maps. Paper maps have a much higher resolution and information density than typical computer displays of the
same physical size, and might be unreadable when displayed on screens at the wrong resolution.[5]

5. Kelebihan Penggunaan Web Mapping
• Informasi mudah disampaikan via web based
• Hardware dan software banyak tersedia,
bahkan banyak yang opensource
• Pemetaan dapat dilakukan dengan
menggunakan browser
• Perkembangan teknologi yang pesat
mempermudah proses bahkan sampai ke
pemetaan kolaboratif.

6. Kekurangan Web Mapping
• Masalah reliability
• Masalah di sumber data yang mahal,
disebagian besar negara data masih berbayar
• Masalah bandwith utk mengakses
• Masalah kualitas, tampilan, dll
• Masalah hak cipta
• Masalah privasi

7. Teknologi Web Mapping
The potential number of technologies to implement web mapping projects is almost infinite. Any
programming environment, programming language and serverside framework can be used to
implement web mapping projects. In any case, both server and client side technologies have to be used.
Following is a list of potential and popular server and client side technologies utilized for web mapping.
• Spatial databases are usually object relational databases enhanced with geographic data types,
methods and properties. They are necessary whenever a web mapping application has to deal with
dynamic data (that changes frequently) or with huge amount of geographic data. Spatial databases
allow spatial queries, sub selects, reprojections, geometry manipulations and offer various import
and export formats. A popular example for an open source spatial database is PostGIS. MySQL also
implements some spatial features, although not as mature as PostGIS. Commercial alternatives
are Oracle Spatial or spatial extensions of Microsoft SQL Server and IBM DB2. The OGC Simple
Features for SQL Specification is a standard geometry data model and operator set for spatial
databases. Most spatial databases implement this OGC standard.
• WMS servers can generate maps on request, using parameters, such as map layer order,
styling/symbolization, map extent, data format, projection, etc. The OGC Consortium defined
the WMS standard to define the map requests and return data formats, while other systems use
standards like Tile Map Service for a similar purpose. Typical image formats for the map result are
PNG, JPEG, GIF or SVG. There are open source WMS Servers such as UMN Mapserver and Mapnik.
Commercial alternatives exist from most commercial GIS vendors, such as ESRI
ArcIMS and CadCorp.