Digimap data in ArcGIS
Guy McGarva
EDINA Geo User Support
Ian Holmes
Poll
What is the one thing you most want to learn today?
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What map data is available from Digimap
How do I get the data from Digimap
What data formats should I use in ArcGIS
Tips on using ArcGIS
Other
Content
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What data is available?
How do I use Data Download to get data for ArcGIS?
What formats should I pick for using in ArcGIS?
How do I load data into ArcGIS?
How do I style my data?
Tips:
• Projections
• Processing
• Resources
Digimap Home Page
What data is available from Digimap?
• Ordnance Survey (OS) – Full range of OS maps and
data available including OS MasterMap and OS
OpenData
• Historic – Detailed historic OS maps from 18431990s
• Geology – Onshore and offshore geological datasets
• Marine – Marine and coastal zone data
• Environment – Land cover datasets
All data can be used in ArcGIS in one form or another!
How do I download map data?
• Data Download –
download OS and
other mapping
data for use in
ArcGIS
• There are similar
applications for all
other collections
Data Download in Other Collections
Using Data Download
Three steps:
1. Select area
2. Choose data
3. Add to basket options to change
format, version
and layers
Basket options
• Select version, format and layers in the basket.
• Options vary between map data products.
What formats should I use for ArcGIS?
Vector
• Shapefile – if available
• File Geodatabase –MM Topo and Building Heights
• GML (for OS MasterMap and VML) – only if needed
Raster
• TIFF – for raster
• ASC (for DTM)
Check format availability
• Check the
Information
boxes.
• Every product
in Vector Data
category
available in
Shape format.
• The most upto-date
contours are
also available
as Shape.
OS MasterMap Topography
• Recommend you take File Geodatabase
for use in ArcGIS (FGDB).
• Alternative: Take GML and convert to
Shape or File Geodatabase using tools
detailed in Help pages.
• Why would I convert GML?
- Can select the feature types you import
- Can merge several orders together
Use Productivity Suite to process GML
• Creates a File
Geodatabase
• Can select
Feature Types to
process
• Can process
multiple Chunks
and Multiple
Orders
• Required for ITN
to build
network dataset
Formats and conversion guidance
http://digimap.edina.ac.uk/webhelp/os/data_information/data_formats/new_data_translators.htm
Download zip file contents
• Within each zip file:
• Folder for each map
product
• Contents text file
• Citations text file
You must extract the data from the zip file before using the data in ArcGIS:
- Either use the Windows ‘built-in’ uncompress option “Extract All” available
when you right click on the zip file
- Or use software such as 7-Zip or WinZip to extract the data from the zip file.
Poll- Where do you get data?
What sources do you use to get data for ArcGIS, select
all that apply:
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Digimap
Built-in Esri Basemaps or Esri Portal
Data.Gov or other open portal
Your own data
Other source
Loading data into ArcGIS
Use the Add Data button
Select Folder Connections to add downloaded data
Can also “Drag and Drop” file into ArcMap
Adding raster data e.g. 25K Raster
- Select multiple files if you
want.
- Will automatically show files
that can be loaded e.g. TIF
files, Shapefiles, ASC or File
Geodatabase
- You might get a warning saying they
have missing spatial reference
information.
- Ignore for now.
Adding Shapefiles e.g. VML
- Select multiple feature
classes
- Note there are separate
feature classes for points ,
lines and areas
- There are separate feature
classes for each tile
- Example tile of VML without
syling
Adding File Geodatabase e.g. MM Topo
- Navigate to .gdb file
- Double click on it
- Feature classes in database
will be displayed
- Select all Feature classes
Displaying Data
If data is not visible,
Right Click on Layer
and click Zoom to
Layer.
It will zoom to the
extents of the
selected map sheet.
Styling vector data in ArcGIS
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Vector data (e.g. OS MasterMap, OS VectorMap Local) will not have
the same appearance as it does in Digimap, when viewed in ArcGIS
May want to consider styling the data to emphasise certain things on
the map, or to try and match the OS cartographic style
For more details see:
http://digimap.edina.ac.uk/webhelp/digimapgis/arcgis/standard_arcgi
s_functions/applying_style_files.htm
Styling options
In ArcGIS – do this in
Symbology tab of
map layer properties:
Option: apply a layer
or style file that
contains styling
information – find
available files in
Digimap Help pages.
Note: Data information pages for each product has a link to
a Style File on it
Style files from Digimap
• Digimap provides style
files for some vector
data products
• Need to look on the
product information
page
• Find this via the Data
Download Information
box  More info link
• Some can be
downloaded from OS
website
• Some products have the
Symbology file in the
download zip
Other sources of style files
For OS MasterMap:
• Productivity Suite:
– symbology files available with the software but must be used with data processed through
Productivity Suite:
http://www.esriuk.com/software/arcgis/productivitysuite/download#
• InterpOSe:
– provide a style file for ArcGIS with the InterpOSe installer
– Must be used with data processed through InterpOSe:
http://misoportal.com/data/interpose-for-digimap/
• These are data conversion tools often used with OS MasterMap – full details in
the Format and Conversion tools page mentioned earlier.
Projections and Transformation in ArcGIS
Need to think about, if:
• You are setting the Coordinate System on an existing
dataset
• You are overlaying data with different coordinate systems
• You want to overlay Esri Basemap data with OS data
• See:
http://digimap.edina.ac.uk/webhelp/digimapgis/index.ht
m#projections_and_transformations/transformations_in
_arcgis.htm
Otherwise: Data in WGS 84 and OSGB 36
What if you want to overlay data or use the Esri Basemaps?
• Most Esri Basemap data
is in WGS 84
• OS data is in OSGB 36
• Showing VectorMap
Local overlaid on the Esri
Imagery Basemap
• Errors of over 100m by
default
Common Geoprocessing Tools
• Merge
• Mosaic
• Clip
• For details see:
http://digimap.edina.ac.uk/webhelp/digimapgis/ind
ex.htm#arcgis/standard_arcgis_functions/viewing_d
ata_in_arcmap.htm
Vector data – Merge tool
• Where your download area covers
multiple tiles, possible to merge the
tiles into one
Image: OS Terrain contours in ArcMap,
before merge (SE England)
Raster data – Mosaic tool
Clip tool
• Where tiles are provided
in large sizes e.g. 100 x
100 km, possible to clip
them to smaller area
• To use the clip tool,
necessary to have a
Shape file of the smaller
area to use as the guide
Image: Vector Map District clipped to
smaller area in ArcMap
Poll
What software do you use most often with geospatial
data?
• ArcGIS
• QGIS or other open source software
• AutoCAD or other CAD software
• I don’t use any GIS/CAD software
• Other
Resources
• Digimap Resource
centre – access
help pages,
guides, FAQs,
videos, case
studies and more.
Help pages
Digimap Resource centre:
http://digimap.edina.ac.uk/webhelp/resources/index.html
PDF exercises
• Exercises available
for download
• PDF step by step
• Some with data
provided
Chat
• Usually manned in
office hours.
Poll
Today’s webinar:
• I learnt something new
• I didn’t learn anything new
• Was a good use of my time
• Was a poor use of my time
• Other