Big Just Got Bigger! Surprises in managing large map collections Ian Holmes EDINA
Big Just Got Bigger!Surprises in managing large map collections
Ian HolmesEDINA
EDINA
delivers online services
Based at Supported by
Vision: To be integral to the quality and productivity of research and education, in the UK and beyond.
Geo-Services
Digimap
• An online mapping and data delivery service• Originally built to provide access to Ordnance Survey
(GB) maps and data - a ‘virtual map library’• Launched in January 2000• Content extended to include:
– Historic OS maps– British Geological Survey data– Marine maps and data (UKHO via Seazone)– Environment data (Centre for Ecology and Hydrology)– Aerial imagery (Getmapping)
• Subscription service with around 65,000 users
Digimap Collections
• Ordnance Survey• Geology• Historic• Marine• Environment• Aerial
Accessing the data: online mapping via Roam
Accessing the data: online mapping via Roam
• Annotation• Data import/export • Save/open• Printing• Measurement tools• No spatial analysis
Accessing the data: forward use
Basket options:• version• format• layers
1: Select area
2: Select data
3: Add to basket
Accessing the data: forward use
• Forward use: Data Download• GIS and CAD users• Access raw data in different formats• Previous versions of data
Digimap for Schools
Digimap for Colleges
Aerial Imagery
• Recent venture with Getmapping• Highest resolution national (GB) dataset: 25cm• Annual updates
Data currency
Data currency
Mosaic – hard edges
Mosaic – data detail
Mosaic – following features
Challenges
• User expectation: now is good
• Sharing data across multiple platforms
Moore’s Law
• Microchip performance doubles every two years
Source: http://www.gotw.ca/publications/concurrency-ddj.htm
Decreasing cost of disk space
Source: http://www.mkomo.com/cost-per-gigabyte-update
Aerial imagery in numbers
• 243,869 1km tiles• 1.7TB• JPEG format
Challenges: mapping
Challenges: mapping
Challenges: mapping
Challenges: printing
Challenges: downloading
Using the data in GIS
• OS MasterMap Building Height Attribute• 25cm aerial imagery• VectorMap Local Raster• OS Terrain 5
Using the data in GIS
OS MasterMap Topography Layer
• Most detailed mapping available
• Supplied in GML format• Provided in GML, DWG and
File Geodatabase formats
Summary
• User expectation/performance– caching
• Currency• Disk space, backup, redundancy
Any questions?