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DEFRA Noise Data API

Hi,

I'm using the modelled noise data such as 'Road Noise - LAeq 16h - England Round 3' by downloading GEOJSON files from the spatial data platform. Is there an API I can use to download the data instead? I've found one for flooding but coming stuck re: noise.

Many thanks

Matthewvincent //

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Hi,

Sorry - I have been able to get the required information via a WFS request however all the results for a GEOJSON are returned in WGS84 format whereas I have requested EPSG:27700 format. The request I am using is:

https://environment.data.gov.uk/spatialdata/road-noise-lden-england-round-3/wfs?service=wfs&request=getfeature&version=2.0.0&typenames=Road_Noise_Lden_England_Round_3&outputFormat=geojson&bbox=187260,522610,188375,523144&srsName=EPSG:27700

Please could you assist?

 

Matthewvincent 0 votes //
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Hi Matthew,

We're looking into this, and we'll let you know when we have an answer.

Thanks,

Dan, DSP team

Data Services Platform team 0 votes //
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Hi Dan,

Thanks for your reply.

Could you also confirm whether there is an positional offset between the WFS data and the WMS data? Just to illustrate my point, please see a screenshot of the online Map service for a random area where the noise is coloured as per the key and the properties are grey boxes:

When I map the same data downloaded using a WFS request (and taking property locations from Ordnance Survey), I get the following results:

 

The noise area is shaded blue and properties are red markers.

I think actually, that the area circled dark blue should really sit over the area circled green for it to match. I therefore think there is some sort of offset built into the WFS data.

For clarity, I also experience the same problem when mapping flood data.

Please could you assist?

Happy to provide more info if required.

Matthewvincent 0 votes //
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Hi Matthew,

There shouldn't be an offset. I have connected to both the WMS and WFS feeds of the noise data in QGIS, and they are opening in EPSG27700, and both in exactly the same location (the only difference is that WFS isn't colour coded). The positions seem to match up with property points as expected.

So the issue may be with the way in which you are processing or transforming the data. I'm not sure how I can help with this.

For future reference, you may be better raising things like this via the DSP Report An Issue service at https://support.environment.data.gov.uk/hc/en-gb/requests/new

Regards,

Dan

Dan Haigh 0 votes //
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Thanks, Dan.

It must be to do with my conversion between 4326 and 27700 in that case. Do you know if there is a solution for outputting to EPSG: 27700 as this will probably solve the issue?

Matthewvincent 0 votes //
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Matthew,

I'm sorry but I haven't heard back from our technical team regarding the coordinate transformation yet.

Dan

Data Services Platform team 0 votes //
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Hi Matthew,

The advice from our technical team is: GeoJSON format uses WGS84, we would recommend the customer uses an output format which supports British National Grid (EPSG:27700).

I guess this means it's not possible to transform the coords into a different projection.

Regards,

Dan

Data Services Platform team 0 votes //
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