Step 1: Select Location
Step 2: Click on Map to select Tiles
Step 3: Options & Buy
OS MasterMap® Imagery (Aerial): 1km x 1km Tiles
Expertly colour-balanced and corrected for geometric distortions (orthorectified), OS MasterMap Imagery Layer is seamless aerial photography of the highest quality that is available off-the-shelf at a consistent and very detailed 25 cm resolution for the whole of Great Britain.
With effect from 1 March 2012 the pricing for OS MasterMap ® Imagery Layer data will be based on a single flat km2 price, calculated individually for each order as follows
|Whole km2 pricing||Licence fee per km2|
|Next 24 km2||£11.00|
|Next 9 975 km2||£5.44|
Discounts are then applied depending on how many terminals that the data has to be used on as well as the licence term.
£225 000 is the OS MasterMap Imagery Layer price for a one year contract, covering Great Britain, for use on 101 or more terminals.
1000m x 1000m
OS Aerial Support Section
Ordnance Surveys FAQs
What is the difference between geocorrected and orthorectified imagery?
OS MasterMap® Imagery Layer is fully orthorectified to provide a high level 1.1 m RMSE accuracy and correct alignment with our other detailed data.
Geocorrected imagery has been fitted to mapped features and does not include a digital terrain model (DTM) to compensate for ground height variations within the image. It has the advantage of being inexpensive to produce, and gives a good approximate fit to vector map data. But since it is not controlled to the National Grid or adjusted to compensate for the ground height variations, it does not inherently provide positionally or geometrically accurate imagery. Update is also a problem since the controls, being based upon mapped features rather than true location, are not necessarily stable.
Orthorectified imagery is created using National Grid control points and a DTM. This means that the distortions inherent in a flat photograph of a three-dimensional object (the earth's surface) are more completely and accurately corrected. An orthorectified image is positionally more accurate, and geometric fidelity (shape) is retained in all terrain, including hilly areas. Also, a consistent scale is maintained throughout the image (as per a map), and future imagery updates will be in the same position.
How closely does Imagery Layer align with other OS MasterMap layers?
All of OS orthorectified imagery in OS MasterMap Imagery Layer uses direct National Grid control or GPS with a suitable transformation in order to achieve our specified positional accuracy. This means that features will align very closely between the image and vector data, within the expected tolerances. The imagery is also revised at the same time as OS MasterMap Topography Layer as part of OS Integrated Revision Programme to ensure that the data layers are synchronised. Together these processes provide imagery that is positionally correct and temporally consistent to maximise interoperability between OS MasterMap layers and your own data.
What is the level of quality that Ordnance Survey has applied to its 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 my area of interest?
Every time a tile is added to your selection the date flown date is displayed besdie the tile reference... eg: NS5965 ( flown=2009-06-23 )
Also part of Ordnance Surveys ongoing commitment to maintenance, they continuously refresh OS MasterMap Imagery Layer as part of their cyclic integrated revision schedule. It is published via an interactive map that shows when different parts of the country were last flown.
What format is OS MasterMap Imagery Layer delivered in?
The OS MasterMap® Imagery Layer that we supply is 1km x 1km tiles in Tagged Image File Format (TIFF);
All files are accompanied by the relevant georeferencing files to enable integration in a GIS (.tfw and .xml files).
TIFF (approx 46.9mb) is one of the most commonly used lossless image formats. TIFF is primarily designed for raster data interchange, and is supported by numerous image-processing applications.
How do I georeference OS MasterMap Imagery Layer tiles?
All of the OS MasterMap Imagery Layer formats can be registered in a GIS or image-processing software. This is achieved in different ways depending on the format, either through the accompanying georeferencing files, header files or with metadata delivered with the image file. A national set of World files is available opposite.
The imagery user guide provides full technical details. Your software supplier will also be able to advise you on this matter.
In Imagery Layer, 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.
Can I obtain archived OS MasterMap Imagery Layer?
No. Ordnance Survey does not currently offer archived OS MasterMap Imagery Layer data, but an archive policy is being developed.
Will OS MasterMap Imagery Layer tiles include metadata information?
Yes, each OS MasterMap Imagery Layer tile is accompanied by a separate XML metadata file in a consistent format across every image in the layer. The metadata is extremely detailed and includes information ranging from imagery capture date to photographic lens focal length. The imagery user guide contains detailed technical information.
Does OS MasterMap Imagery Layer contain TOIDs?
As the OS MasterMap Imagery Layer is a raster product, unlike the other (vector) layers in the OS MasterMap product range, TOIDs® are not part of the data specification. However, OS MasterMap layers are designed to be used together in order to create a synchronised tool for analysis of many different types of data in a GIS. Thus other layers can be drawn over imagery to provide information, such as TOIDs.
- Raster - Flat
- Format: Tiff
- Large Scale
- Worldfile and XML supplied
- Best viewed at 1:1250 in GIS
- 96% of data is less than 5 years old
- 55% is less than 3 years old
- Risk Manageent
- Site Planning
- Property Development
- Asset Management
- Agricultural Services
- Environmental Monitoring
- 1, 2 and 3 years available
- Licence Number supplied with each purchase
Ordnance Survey Large Scale CAD (layered) data.
OS MasterMap Topography Layer in DXF or DWG with optional contours at 0.5m, 1m or 2m intervals.
1:10 000 Scale Raster provides a backdrop map product at a mid-scale on which you can overlay your information, to provide a geographic context for your data. Available in 5km x 5km and in Backdrop Colour (washout), Black and White or Colour.
OS 1:25 000 Scale Colour Raster is the digital form of Ordnance Surveys popular OS Explorer Map. The detailed representation of the countryside in a way that is easy to interpret makes it particularly suited for displaying environmental applications. 10km x 10km Tiles.
10k Vector data for CAD or GIS - OS Vector Map Local derived - not as detailed as the large scale OS Mastermap but this mid scale vector product is particularly useful for covering larger areas.