.svg?alt=media&token=1e8c5cb8-8313-4dee-9a83-897615d7ab1f)
.svg?alt=media&token=52cad126-f5f3-479b-a4fe-3db53f640273)
January 2024
This release note provides information about the latest release of OS MasterMap (OSMM) Topography Layer, released to customers on 04 January 2024
OSMM Topography Layer product count
The following table contains product counts for this release of OSMM Topography Layer data. The dates shown are extraction dates, not release dates.
Total Feature Count
506 484 147
506 917 679
Count of Topo Area
126 697 703
126 804 006
Count of Topo Line
348 999 864
349 295 187
Count of Topo Point
4 333 471
4 345 063
Count of Topo Bline
533 428
532 991
Count of Topo CartoSym
3 734 550
3 745 400
Count of Topo CartoTxt
22 185 131
22 195 032
Total Count of Deletes
482 784
333 884
Count of Topo Area deletions
78 620
70 410
Count of Topo Line deletions
360 998
231 489
Count of Topo Point deletions
3 993
3 420
Count of Topo Bline deletions
591
828
Count of Topo CartoSymcc deletions
9 635
7 670
Count of Topo CartoTxtcc deletions
28 947
20 067
Total Count of Inserts
915 049
767 416
Count of Topo Area inserts
214 888
176 713
Count of Topo Line inserts
624 246
526 812
Count of Topo Point inserts
16 055
15 012
Count of Topo Bline inserts
398
391
Count of Topo CartoSym inserts
21 829
18 520
Count of Topo CartoTxt inserts
37 633
29 968
Total Count of Modifications
681 711
515 536
Count of Topo Area Modifications
289 725
246 717
Count of Topo Line Modifications
369 012
254 055
Count of Topo Point Modifications
374
254
Count of Topo Bline Modifications
674
955
Count of Topo CartoSym Modifications
57
45
Count of Topo CartoTxt Modifications
21 869
13 510
COU Size (bytes)
402 922 509
347 863 984
New formats available
Alongside GML format, OSMM Topography Layer is also available in GeoPackage and vector tiles formats (from March 2023). Please see the Getting Started with GeoPackage and Getting Started with Vector Tiles guides for more information on using these new formats. The product is supplied as an online download. You can download data in its various formats from the OS Data Hub.
Discrepancies
In this release 6 minor errors were detected, which is 20 less than the 26 errors found in the last refresh. Of these errors, 2 have existed since the previous refresh – these are minor issues caused by conflict (where the geometry of adjacent feature has not been updated to match), but there are no visible issues.
Land cover refinement changes
The land cover specification for rural geographies has been refined. The Mountain and Moorland refinement was completed in 2022.
The rural geography updates began capture in May 2022. The initial updates fed through to the July 2022 release of OSMM Topography Layer, with the multi class land cover polygons completed in December 2022. The single class land cover polygons will continue to feed through to product from April 2023.
The following two tables articulate this specification refinement:
Old land cover specification
Urban
0.1hectares (ha) (1 000m²)
5m
Rural
0.1hectares (ha) (1 000m²)
10m
Mountain and moorland
1.0hectares (ha) (10 000m²)
10m
New land cover specification
Urban
0.1hectares (ha) (1 000m²)
5m
Rural
0.1hectares (ha) (1 000m²)
5m*
Mountain and moorland
0.1hectares (ha) (1 000m²)*
5m*
The asterisk symbol (*) shows which criteria have been refined.
The land cover specification refinement means that the rural land cover data within OSMM Topography Layer will become more granular, producing a more detailed view made up of smaller more numerous polygons. This provides users with more accurate data that meets each individual’s specific requirements. These changes are purely refinements and do not change the data attribution.
Annex A shows three examples of how the rural land cover refinement is being translated into OSMM Topography Layer.
Changed TOIDs
Numerous TOIDs (Topographic Identifiers) have changed since the last refresh, resulting in a visual difference in the data. The list below shows a sample of changed TOIDs and their locations that you can use as 'lookup samples' to validate that your latest supply has updated correctly:
osgb1000000168404255
328579.99, 958515.98
osgb5000005152517605
348374.945, 431019.423
osgb1000001824692637
541419.437, 101834.574
osgb1000000385134315
188967, 835637.5
osgb5000005299962750
416833.55, 444757.47
osgb1000000013827617
508743.536, 482017.503
Next release
The next release of OS MasterMap Topography Layer is scheduled for 19 February 2024.
Annex A: Rural land cover specification refinement examples
Below are three real-world examples of how the rural land cover specification refinement has affected the data within OSMM Topography Layer. The examples showcase three areas in southern Scotland where the specification refinement has broken up one land polygon within the Topographic Area Feature Type into smaller, separate polygons.
Example one
Location of example area one:
NS4505
NS 47825 05240
247790.7, 605224.0
TOIDs for example area one:
OSMM Topography Layer (July 2022): osgb1000000316775097
OSMM Topography Layer (August 2022): osgb5000005297485451, osgb5000005297485455, osgb5000005297485456
Source imagery of example area one for comparative purposes:
Data before the rural land cover specification refinement update (OSMM Topography Layer – July 2022):
Data after the rural land cover specification refinement update (OSMM Topography Layer – August 2022):
Example two
Location of example area two:
NX3540
NX 37464 41871
237419, 541979
TOIDs for example area two:
OSMM Topography Layer (July 2022): osgb1000000318639911
OSMM Topography Layer (August 2022): osgb1000000318639911, osgb5000005298080383, osgb5000005298080465
Source imagery of example area two for comparative purposes:
Data before the rural land cover specification refinement update (OSMM Topography Layer – August 2022):
Data after the rural land cover specification refinement update (OSMM Topography Layer – October 2022):
Example three
Location of example area three:
NX6550
NX 68975 51146
268968, 551139
TOIDs for example area three:
OSMM Topography Layer (July 2022): osgb1000000319079420
OSMM Topography Layer (August 2022): osgb1000000319079420, osgb5000005298106224
Source imagery of example area three for comparative purposes:
Data before the rural land cover specification refinement update (OSMM Topography Layer – August 2022):
Data after the rural land cover specification refinement update (OSMM Topography Layer – October 2022):
Last updated
