London50_RGB 2017.sid (1 file):


This file contains aerial imagery of the City of London, stored in a multiresolution seamless image database (MrSID, Generation 3 format).  The image pixel resolution is 10 cm, and the data is compressed at a ratio of 50:1.  The file size is approximately 4.6 GB.


The image data is adjusted to reference ‘grid’ units of measurement.  However it should be noted the aerial imagery is not suitable for accurate measurements and/or scaling.


Coordinate system:

UTM, Zone 17


NAD 83, 6° projection

Central Meridian:

81° West


1:15400 (approx)


April 2017

Pixel resolution:

10 cm

File size:

4.6 GB

Source format:





London50_RGB 2017.sdw (1 file):


This MrSID World file contains georeferencing information which is used to position the imagery data stored in the SID file in real-world coordinates.  The file size is approximately 1 KB.


Please be aware the SID and SDW files must be co-located in the same folder location to ensure the imagery data can be used correctly by compatible software.


Please refer to the LizardTech website www.lizardtech.com for additional technical information about the MrSID file format and for support related to Plug-ins, viewers, tools and utilities that can be utilized to view and manage MrSID files.