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#1
LukeEdAllen

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Hi everyone,

I am trying to geocode a bunch of addresses using postcodes into http://www.gpsvisualizer.com/geocode to get the long/lat coordinates. I then intend to bring them into ArcMap in a textfile and display them.

I just wanted to ask (I know there is going to be some level of inaccuracy) will this lat/long that are displayed back after putting in a british postcode (for eg, CF37 1TH) work ok within the british national grid projection?

Just wanted to run this by everyone as I am quite vague with different projections - and wondered if because it was an american websitesite it might be a bad idea to use?

thanks for any help

Luke

#2
gregsd

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Hi everyone,

I am trying to geocode a bunch of addresses using postcodes into http://www.gpsvisualizer.com/geocode to get the long/lat coordinates. I then intend to bring them into ArcMap in a textfile and display them.

I just wanted to ask (I know there is going to be some level of inaccuracy) will this lat/long that are displayed back after putting in a british postcode (for eg, CF37 1TH) work ok within the british national grid projection?

Just wanted to run this by everyone as I am quite vague with different projections - and wondered if because it was an american websitesite it might be a bad idea to use?

thanks for any help

Luke


Why don't you use OS CodePoint Open to geocode the addresses in ArcMap? Sorry, I can't tell you how as I only use MapInfo, but it should be fairly easy to do.


Greg Driver

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#3
LukeEdAllen

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Hi everyone,

I am trying to geocode a bunch of addresses using postcodes into http://www.gpsvisualizer.com/geocode to get the long/lat coordinates. I then intend to bring them into ArcMap in a textfile and display them.

I just wanted to ask (I know there is going to be some level of inaccuracy) will this lat/long that are displayed back after putting in a british postcode (for eg, CF37 1TH) work ok within the british national grid projection?

Just wanted to run this by everyone as I am quite vague with different projections - and wondered if because it was an american websitesite it might be a bad idea to use?

thanks for any help

Luke


Why don't you use OS CodePoint Open to geocode the addresses in ArcMap? Sorry, I can't tell you how as I only use MapInfo, but it should be fairly easy to do.



Hi Greg, many thanks for that - Im assuming I would just take the easting and northings from this csv file for each postcode I require and import them into my own table?

#4
gregsd

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Hi everyone,

I am trying to geocode a bunch of addresses using postcodes into http://www.gpsvisualizer.com/geocode to get the long/lat coordinates. I then intend to bring them into ArcMap in a textfile and display them.

I just wanted to ask (I know there is going to be some level of inaccuracy) will this lat/long that are displayed back after putting in a british postcode (for eg, CF37 1TH) work ok within the british national grid projection?

Just wanted to run this by everyone as I am quite vague with different projections - and wondered if because it was an american websitesite it might be a bad idea to use?

thanks for any help

Luke


Why don't you use OS CodePoint Open to geocode the addresses in ArcMap? Sorry, I can't tell you how as I only use MapInfo, but it should be fairly easy to do.



Hi Greg, many thanks for that - Im assuming I would just take the easting and northings from this csv file for each postcode I require and import them into my own table?



Luke,

The way I'd do this in MapInfo would be to open the CodePoint data and create a 'table' with a point for each postcode based on the x, y coordinates. There is then an option to geocode the addresses by matching the postcode to that in the CodePoint data and assigning the matched address the point from the CodePoint data.

I'm sure someone on here will be able to tell you the best approach to doing this in ArcMap.

Greg.


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#5
LukeEdAllen

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[/quote]


Luke,

The way I'd do this in MapInfo would be to open the CodePoint data and create a 'table' with a point for each postcode based on the x, y coordinates. There is then an option to geocode the addresses by matching the postcode to that in the CodePoint data and assigning the matched address the point from the CodePoint data.

I'm sure someone on here will be able to tell you the best approach to doing this in ArcMap.

Greg.
[/quote]

Hi greg, thanks for the response again --- I might be interpreting this wrong but the way I would do this would be to just take the postcodes I need into a new csvfile.... create my own columns for address (which I know) postcode (which I know) and another field as a comment of what type of feature it is, house/shop/doctors etcetc. I would then look up the same postcode in the codepoint data and copy its eastings and northings into my own csv file under easting and northings columns. Finally I would input this new csv into arcmap and display it as a point file using the eastings and northings...

Now is this a really inefficent way to geocode or something? I have sort of teached my self geocoding and I dont claim to be a GIS super guru so I would be more than open to feedback if this is a really inefficent way to do it - I hope I make some sort of sense. :)

Thanks again, :)

Luke

#6
Nick H

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Hello Luke, I don't think there is way of producing a CSV containing postcodes, street addresses and grid references using any of the OpenData datasets.

The Codepoint data has postcodes and grid references, but no addresses. The Locator data has street addresses and grid references but no postcodes. Great care has been taken to ensure that it is not possible to combine automatically the data from the two sets.

So it looks as if you might be best off selecting one of these datasets, Codepoint or Locator, thinning it out as required and then adding the missing data by hand, using Google, or what ever, as you suggested.

None of the OpenData layers have been made easy to use. There are a few reasonably decent layers but most of OS OpenData is a rag-bag of old tat I'm afraid.

Regards,
Nick.
Caversham, Reading, England.

#7
gregsd

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Hi Luke,



I don’t think there’s a wrong way to do it and I guess it does depend on the tools you have to hand!

With MapInfo, we can open a text/csv/excel file with a list of addresses and postcodes and then match the postcodes to the CodePoint data and assign a point for each matching postcode automatically.
So we don’t have to manually match the postcode, copy the coordinates and then create the points as this is all done in one operation. Your approach does seem to be labour intensive, especially if you a lot of addresses to geocode!



May be this might help -

http://webhelp.esri....le_of_addresses



Let us know how you get on.

Greg.


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#8
LukeEdAllen

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Hi Guys, thanks for the responses.

Greg - thanks for the link... have been reading it and I think to geocode using that method you must use an address locator within ArcGIS... for this I think it requires that you have some form of street dataset with an address attribute.

The work I am doing doesnt really use this - I am basically using a boundary file just like this one in the following image http://oem.bmj.com/c...22/F1.large.jpg - Lower Super output Areas - basically these are boundaries used for statistical analysis with census data etc.

Its not really necessary for me (I dont think) to use street data so I guess I need to use long/lat and easting and northings to geocode my point features onto a map like this.

Again I would have to agree with you that my method is abit long winded especially if you have to geocode 100 + supermakets etc but I dont think there is a way to automate it unless your using street data with an address attribute that ArcGIS can use.

Maybe I'm wrong those :)

#9
LukeEdAllen

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Hi guys, I've looked into geocoding within ArcGIS and have came across an address locator function, however, this uses street network data to geocode an address - for the USA the general dataset used is called Street Map - does anyone know which dataset would be used for the UK?

I did look at the OS Mastermap ITN dataset or is this more for road routing analysis?

Thanks for any help :)




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