AdaTheDev/Ordnance-Survey-Code-Point-Data-Importer — Issue #1: Needs to adhere to Positional Quality Indicator
Author: AdaTheDev
Created: 2012-01-19 20:33:29+00:00
State: open

Positional Quality Indicator field in the CodePoint data files indicate the level of accuracy of the coordinates supplied.

From OS User Guide:
10=Within the building of the matched address closest to the postcode mean determined automatically
by Ordnance Survey.
20=As above, but determined by visual inspection by NRS.
30=Approximate to within 50 m of true position (postcodes relating to developing sites may be within
100 m of true position).
40=The mean of the positions of addresses previously matched in ADDRESS-POINT but that have
subsequently been deleted or recoded (very rarely used).
50=Estimated position based on surrounding postcode coordinates, usually to 100 m resolution, but 10 m
in Scotland.
60=Postcode sector mean (direct copy from ADDRESS-POINT). See glossary for additional information.
90=No coordinates available.

So, if quality = 90 then there are no coordinates available but currently those are still imported and could be affecting the calculated district/sector averages.