This document discusses Ordnance Survey Ireland's process for automating the production of 1:5000 scale raster maps from their vector data using Mapnik rasterization. Key points: - OSI previously produced paper 1:5000 maps but needed an updated digital raster product for emergency services. - Mapnik was used to style and rasterize OSI's 130-layer vector dataset representing topographical features. - The process involved creating 80 style rules in Mapnik to represent features, then rasterizing over 7,000 tiles covering Ireland at 1:5000 scale. - Challenges included inconsistencies in the source vector data and automating processing of the large dataset, which was addressed using FME and server-

1. National Map Production with
Mapnik Rasterizer
Ordnance Survey Ireland- Vector to Raster
Ciara Beddy
IMGS

2. Ordnance Survey Ireland- National Mapping
Agency
Ordnance Survey creates and maintains
Ireland’s mapping and related geographic
databases
Produces a number of mapping products in
a variety of scales in both digital and paper
formats
One of the main departments and products
produced by OSI are Large scale maps
(1:1000, 1:2500, 1:5000)

3. OSI Raster Mapping- 1:5000
OSI Raster product is derived from vector data and reproduced like for like
The existing vector (point, line, polygon and text) dataset is coded to represent
topographical features – Total of 130 possible layers
FEATURE_CODE DESCRIPTION GEOM
512 FENCE AND WALL POLYGONS POINT,LINE,POLY,TEXT
526 DECIDUOUS FORESTRY POINT,LINE,POLY,TEXT
527 CONIFEROUS FORESTRY POINT,LINE,POLY,TEXT
531 POLYGONS AND NAMES OF RIVERS POINT,LINE,POLY,TEXT
533 NAMES AND OUTLINES OF LAKES POINT,LINE,POLY,TEXT
550 MOTORWAY GEOMETRY POINT,LINE,POLY,TEXT
589 SOLID BUILDINGS POINT,LINE,POLY,TEXT
611 TOWNLAND BOUNDARY GEOMETRY POINT,LINE,POLY,TEXT

4. OSI Existing Raster Data
At present OSi have no
available resource to produce
a current 1:5000 raster product
Last produced in 2009, the
data is outdated
Poor Quality
Existing OSi Raster Dataset is in use by emergency callout services, Fire,
Ambulance and Police

5. MapnikRasterizer
OSi turned to IMGS & FME to automate the provision of a country wide raster dataset
Use of Mapnik Rasterizer to style the 130 feature codes

6. There are approx 7,000 tiles covering Ireland, each measuring
4000m x 3000m (1200ha). Each tile represents a 1:5000 raster
Tiles are made up OSi Vector data in a combination of scales
1:1000, 1:2500 & 1:5000
OSI Raster Mapping 1:5000 Coverage
1:2500 & 1:1000 NTF Tiles

7. Mapnik High Level Process
A total of 80 style rules are created that have one or more layers
associated with each.
Build complex styles very easily using the symbolisers in Mapnik
and simple .png files
Most commonly used Symbolizers ;
LINE PATTERN
POLYGON PATTERN
POINT- TRANSFORM

8. Demonstration

9. Challenges Source Data
Source Data– Inconsistency
Data stored in wrong layer
Duplicated data- Both line and polygon
You can use any of FME’s 460 transformers to validate the data and correct it
to meet the requirements before processing to Mapnik- The output was
greater than then input

10. Challenges- Running the data
The volume of data required to be processed needed a automation workspace and
run on Server

11. End Result
Vector GeoTIFF

12. Why is this transformer so powerful?
Graphic interface for
Mapnik
Sophisticated symbols &
Shading
Transformation
Possibilities
Automation