1.
Live Geoinformation with
Standardized Geoprocessing Services
Theodor Foerster, Bastian Baranski &
Harald Borsutzky
AGILE 2012

2.
What is your initial thought on Geo
Web Services?
http://purl.net/ifgi/isw2011

3.
Performance

4.
Scalability

5.
Usability

6.
Research @
Integration of Geodata
and Processes
Live
Geoinformation
Origin of Communication
Geodata of Geodata

7.
Web Service interaction
Current
Desired
Improved user experience
Improved performance & scalability

8.
Web Processing Service (WPS)
Data Information
WPS
Process 1
GetCapabilities Process 2
DescribeProcess Process n
Execute

9.
Requirements
• Progressive transfer
• Handling, processing, creating of geodata
streams
• Loss-less encoding and transfer of geodata
• Interoperability & portability

10.
Approach
• Asynchronous communication
• Input/output as reference
• Start processing immediately after receiving
the first piece of data
• HTTP Live Streaming

11.
HTTP Live Streaming
• HTTP-based Media Streaming Protocol
• Sequence of small HTTP-based file downloads
• M3U playlist containing media chunk or sub-
streams

12.
Playlist examples
#EXTM3U
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1280000
http://example.com/low.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2560000
http://example.com/mid.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=7680000
http://example.com/hi.m3u8
#EXTM3U
#EXTINF:8,
http://priv.example.com/fileSequence2680.ts
#EXTINF:8,
http://priv.example.com/fileSequence2681.ts
#EXTINF:8,
http://priv.example.com/fileSequence2682.ts

13.
Streaming WPS

14.
Tweaks
• Example playlist endpoint
– http://host:port/wps/playlist?id=123&pol
lingRate=10
• Polling rate
• Update of playlist
– New items
– Remove retrieved items

15.
Use case
• Generalization
– Simplifying street geometries
• Data
– OpenStreetMap
– Available in playlist format
• Implementation
– 52°North WPS – pluggable & extensible
– GWT Client

16.
Processing of OSM data

17.
Processing of OSM data

18.
Processing of OSM data

19.
Processing of OSM data

20.
Demo

21.
Evaluation - memory footprint
Streaming approach
Reference

22.
Evaluation - performance
Time elapsed (ms)
Number of features

23.
Implementation available
www.52north.org/wps

24.
Outlook
• Enhance other services with HTTP Live
Streaming
– Data and sensor services
– Workflows & scheduling
• Extend to other use cases
– Live analysis of plane tracks (ADS-B) & ship tracks
(AIS)

25.
Conclusions
• Live Geoinformation
– Data  information
– Streaming
– HTTP Live Streaming
• Improved performance & scalability
• Improved user experience
• Processing of potentially unlimited streams of
sensor data
• Relevant for other service types

26.
Thanks for your attention!
swsl.uni-muenster.de
@tf_tweetz