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- Removal of Esri Image Services
Removal of Esri Image Services
Created: 18/12/2024 Updated: 02/02/2024
In line with Defra’s policy, and previous announcements, the DSP will concentrate on the provision of data in Open Standards - Esri Image services will not be supported or available from 15th December and are being replaced with equivalent WCS and WMS services.WMS show a summarised version of the elevation data, with the WCS services providing the elevation where Hillshade is also published.
We are also taking this opportunity to update to our existing Survey services – to support future data updates, LIDAR Composite DSM and DTM feeds shall be re-published with an updated endpoint, with the Year of release suffix being removed and now modified to describe First and Last Return. Existing services e.g.:
https://environment.data.gov.uk/spatialdata/lidar-composite-digital-terrain-model-dtm-1m-2022/wms
Shall be changed to the new format, alongside updated metadata, and remain consistent for future updates:
https://environment.data.gov.uk/spatialdata/lidar-composite-digital-terrain-model-dtm-1m/wms
Users will need to update to the new format, but shall be persistent for future updates, providing the most up-to-date data without users having to adjust annually. WMS urls have been updated. Guidance on using WCS are available as FAQs.
Web Coverage Services:
FAQs:
What image services does the DSP Support?
Web Coverage Services (WCS) are an Open Geospatial Consortium (OGC) supported standard for serving and retrieving multi-dimensional coverages over the web in geospatial applications including QGIS and ESRI ArcGIS Desktop. For further information on WCS please refer to: Web Coverage Service - Open Geospatial Consortium (ogc.org).
WCS enables users to request the ‘raw’ pixel data such as the elevation of a dataset. WCS services are available for the LIDAR Composite elevation models, SurfZone Digital Elevation Model (DEM) and Vegetated Object Model datasets. WCS services are supported in the latest available OGC version - 2.0.1.
Together with updated Web Map Services, Web Coverage Services provide an equivalent service to Esri image services, in a non-proprietary and open format.
How can I use WCS Elevation Services in ESRI ArcGIS Desktop / Pro?
To use the Web Coverage Services in ESRI ArcGIS Desktop please refer to the Adding WCS Services to ArcMap documentation. We are aware of some compatibility issues and are working towards resolving this issue. FAQs shall be updated in due course.
WCS in ArcGIS does not support statistics and raster datasets can only be viewed using a ‘stretch’ render. To apply a stretch render correctly you will need to manually enter the statistics for the datasets using the values in the table below into the symbology > statistics pane:
Table of values required to apply a stretch render to raster datasets.
Dataset | Min | Max | Mean | Std Dev |
-409.05 | 978.05 | 104.63 | 107.52 | |
-408.88 | 977.99 | 110.35 | 112.50 | |
-409.66 | 1326.96 | 105.15 | 107.30 | |
-322.65 | 1388.96 | 110.91 | 112.35 | |
-48.59 | 979.63 | 105.96 | 105.92 | |
-48.58 | 979.58 | 105.96 | 105.92 | |
-92.53 | 323.39 | 35.47 | 75.04 | |
0 | 70 | 1.19 | 3.89 |
How do I set No Data values in WCS?
The WCS returns GeoTIFFs with ‘NoData Value=-3.4028235e+38’. The GeoTIFF contains a 2D array of numbers, so it can’t contain a string saying ‘no data’ but rather it has some pixels with values =-3.4028235e+38. How this information is supplied is handled by the client and determines how this information is displayed.
For ArcGIS users, please refer to:
https://desktop.arcgis.com/en/arcmap/latest/manage-data/raster-and-images/nodata-in-raster-datasets.htm where users need to adjust their settings.
When I add a WCS into ArcGIS Pro, the service appears mainly or all black, is this right?
If this is happening, it’s probably due the default symbology being applied, a clue is if you can see infinity values displayed in your contents (see screenshot below).
This issue can be addressed by:
Right click the layer in the Contents panel and select the Symbology option.
In the bottom half of the Symbology pane, under the statistics option you can either;
a. Select DRA, if you are only interested in the extent of your current screen. With this option, the Map window will update to display a Greyscale image:
b. Alternatively, select the Custom option and manually set the minimum and maximum values manually:
I am unable to connect to the WCS in ArcGIS Pro using ‘Connections’ tool in the ‘Insert’ ribbon, how do I access the data?
Users can us the Make WCS Layer (Data Management) tool, which is licensed in all ArcGIS Pro license types (Basic, Standard and Advanced).
Steps to open a DSP WCS layer, are as follows:
Open the Make WCS Layer tool
Enter a WCS URL - https://environment.data.gov.uk/spatialdata/lidar-composite-digital-terrain-model-dtm-1m/wcs? but only up to the question mark after WCS as above
The template extent will populate itself, but users can change the extent of a layer or the current extent if required. Set a suitable name for the output layer. Users should see something as below - the Input WCS Coverage will change by itself after a user enters the above URL. When ready click Run.
Users can now apply the stretch as instructed at the bottom of the original instructions - Removal of Esri Image Services - DSP Knowledgebase - Data Services Platform Service Desk
The below example is using DRA (Stretch - 2SDs) over Princes Risborough.
