OS MasterMap Imagery Layer
When you need the visual feel for a location, the aerial photography of OS MasterMap® Imagery Layer gives you the real-world view.
Using our aerial imagery to check road markings, tree canopies or site entrances cuts down the need for site visits, so you can save money and manage time more efficiently.
For engineers, for surveyors, for planners, Imagery Layer is a revelation. It's aligned to OS MasterMap Topography Layer and incredibly detailed, expertly colour-balanced and corrected for geometric distortions.
OS MasterMap Imagery Layer is an off-the-shelf product for the whole of Great Britain. You can get it under perpetual use terms – ideal for projects – as well as fixed-term licences.
Active capture programme
More than 98% of our imagery is less than five years old; 66% is less than three years old. Check imagery currency on our interactive map.
OS MasterMap Imagery Layer uses the same source imagery that underpins our large-scale data updates. Our processing software produces true-orthorectified imagery, removing building lean from aerial imagery to give you a consistent top-down view.
Detail that's easy to interpret
You can easily spot properties with solar panels, conservatories and other home improvements, thanks to the layer's 25cm resolution. This makes the product ideal for planning and environmental monitoring.
|Key features||What this product offers|
JPEG, geoTIFF and ECW
XML format for each block, including day, month and year flown
Quarterly (February, May, August and November), as part of our 3-5 year cyclic revision programme synchronised with large-scale data updates.
Download or, for large orders, portable hard drive
Quarterly full supply or change-only update
How is this data supplied and what do I need to use it?
Orders of OS MasterMap Imagery Layer covering a large area are supplied on a portable hard disk. If the file size of your order is smaller than 2 Gb, you can get your data from our FTP server.
You'll need geographic information system (GIS) software to use Imagery Layer.
How do you ensure the quality of your imagery?
Ordnance Survey has invested considerable resources and worked closely with its imagery suppliers to provide orthorectified imagery that achieves the consistently high quality demanded by our customers.
Unlike other data sources, such as topographic data, imagery can be very subjective. It is difficult to quantify specific tolerances for atmospheric conditions, such as haze. We ensure that our suppliers adhere to a detailed set of quality levels for the key aspects of imagery with an emphasis on data quality over image appearance alone. For instance priority is given to ensuring detail such as road markings can be seen within shadows and to positional accuracy. These acceptable quality levels are summarised in the user guide and include:
- the photography and how it is captured;
- the standard of equipment used for scanning the imagery;
- the controls and height models used for orthorectification; and
- geometric fidelity (shape), absolute accuracy (position), radiometric accuracy (colour), image appearance (blemishes and obstructions) and mosaicking.
All suppliers are required to pass a detailed accreditation programme to ensure that they can consistently deliver to specification. As new imagery is flown it is rigorously tested against the acceptable quality levels to maintain standards throughout the production flowlines. Any imagery that does not meet the specification is rejected.
How can I find out the currency of imagery for my area of interest?
As part of our ongoing commitment to maintenance, we continuously refresh OS MasterMap Imagery Layer as part of our cyclic integrated revision schedule. We publish an interactive map that shows when different parts of the country were last flown.
For more detailed information, including planned flying and progress of imagery in production, please contact your account manager.
What do you mean by 'seamless' imagery?
The imagery in OS MasterMap Imagery Layer is seamless in that it is colour balanced and edgematched. This ensures that analysis of information across image boundaries is not seriously hampered by misalignment or inconsistency.
Variations because of time of day differences (for example, lengthening shadows, colour changes), time of year differences (for example, vegetation changes, river levels) and age differences (for example, new developments, and road changes) mean that some variation is inevitable and an overzealous attempt at imposing an artificial evenness would be misleading.
Great care is taken to ensure that imagery is 'stitched' together in a seamless manner to avoid distortion to features, such as buildings. We collect imagery in strips with a generous overlap between each photograph and then use seamlines to select the centre of each image.
The same principles are used to place new imagery updates into the layer. As the imagery is supplied by 1km x 1km tiles, these can contain more than one date of imagery. The date flown on the metadata will always be the oldest imagery present in the tile, however this is usually only a small percentage of the actual content.
OS MasterMap Imagery Layer is available under the following Licences:
Explore our data
You’re welcome to try out this data for free under our Data Exploration Licence.
Internal business use
When using OS data in your own business, you need our Framework Contract (Direct Customers) together with a data contract.
Creating products or services
To use this data commercially in your own products and services, or to distribute it, you will need to sign up to our Framework Contract (Partners) and a relevant defined use contract. This will vary depending on what you’re going to do with the data.
Collective mapping agreements
These products are available to members of public sector organisations under the following agreements:
Find out more in our Public sector licensing guide ›
This product is available under the: