This release note provides information about the latest release of OS MasterMap (OSMM) Topography Layer, released to customers on 19 February 2024.
The following table contains product counts for this release of OSMM Topography Layer data. The dates shown are extraction dates, not release dates.
| OSMM Topography Layer | Count on 14/12/2023 (Previous Release) | Count on 01/02/2024 (Current Release) |
|---|---|---|
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.
In this release 7 minor errors were detected, which is 1 more than the 6 errors found in the last refresh. Of these errors, 1 has existed since the previous refresh. 6 of these are minor issues – these are minor issues with no visible issues, and there is 1 serious error of a double digitised line.
We aim to have all errors resolved prior to the next release as part of ongoing quality improvements.
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:
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.
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:
The next release of OS MasterMap Topography Layer is scheduled for 02 April 2024.
| Geographic Area | Minimum Area Size for Land Cover | Minimum width |
|---|---|---|
| Geographic area | Minimum Area Size for Land Cover | Minimum Width |
|---|---|---|
| TOID | Location (i.e. XY coordinates) |
|---|---|
Total Feature Count
506 917 679
507 375 850
Count of Topo Area
126 804 006
126 911 673
Count of Topo Line
349 295 187
349 600 457
Count of Topo Point
4 345 063
4 362 057
Count of Topo Bline
532 991
532 911
Count of Topo CartoSym
3 745 400
3 763 697
Count of Topo CartoTxt
22 195 032
22 205 055
Total Count of Deletes
333 884
352 971
Count of Topo Area deletions
70 410
72 340
Count of Topo Line deletions
231 489
246 393
Count of Topo Point deletions
3 420
4 698
Count of Topo Bline deletions
828
433
Count of Topo CartoSymcc deletions
7 670
11 208
Count of Topo CartoTxtcc deletions
20 067
17 899
Total Count of Inserts
767 416
811 142
Count of Topo Area inserts
176 713
180 007
Count of Topo Line inserts
526 812
551 663
Count of Topo Point inserts
15 012
21 692
Count of Topo Bline inserts
391
353
Count of Topo CartoSym inserts
18 520
29 505
Count of Topo CartoTxt inserts
29 968
27 922
Total Count of Modifications
515 536
600 677
Count of Topo Area Modifications
246 717
294 892
Count of Topo Line Modifications
254 055
291 597
Count of Topo Point Modifications
254
326
Count of Topo Bline Modifications
955
628
Count of Topo CartoSym Modifications
45
132
Count of Topo CartoTxt Modifications
13 510
13 102
COU Size (bytes)
347 863 984
386 470 897
Urban
0.1hectares (ha) (1 000m²)
5m
Rural
0.1hectares (ha) (1 000m²)
10m
Mountain and moorland
1.0hectares (ha) (10 000m²)
10m
Urban
0.1hectares (ha) (1 000m²)
5m
Rural
0.1hectares (ha) (1 000m²)
5m*
Mountain and moorland
0.1hectares (ha) (1 000m²)*
5m*
osgb1000000175416836
332000, 721912.22
osgb1000000230216079
335945.87, 440115.421
osgb5000005128685631
578813.895, 172187.251
osgb5000005327816366
265014.445, 842929.902
osgb5000005328747598
400486.093, 278819.54
osgb5000005154766496
617199.12, 165232.91
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.
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):
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):
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):
| 5km Tile | OS Grid Reference | Coordinates (OSGB36) |
|---|---|---|
| 5km Tile | OS Grid Reference | Coordinates (OSGB36) |
|---|---|---|
| 5km Tile | OS Grid Reference | Coordinates (OSGB36) |
|---|---|---|
NS4505
NS 47825 05240
247790.7, 605224.0
NX3540
NX 37464 41871
237419, 541979
NX6550
NX 68975 51146
268968, 551139
