On Sun, Jun 23, 2013 at 1:12 PM, Bryce Nesbitt <span dir="ltr"><<a href="mailto:bryce2@obviously.com" target="_blank">bryce2@obviously.com</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br><div class="gmail_quote"><div>At SOTM-US (State of the Map US) I spoke to Steven Johnson of the Census Bureau on the issue of what data USPS actually has internally (as the Census Bureau has some special licensed access to this data).</div>
<div><br></div></div></blockquote><div>Yes, just to amplify: the Census Bureau purchases the Delivery Sequence File (DSF) from USPS on an ongoing basis (at least 2x/year). The use of the DSF dates from 1994 and Congressional authorization was required for the Bureau to use the DSF. The DSF served as the foundation for the Bureau's Master Address File (MAF). The DSF is by far the largest source of address data for the Bureau, in excess of 90%.<br>
<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="gmail_quote"><div></div><div>Apparently, the USPS does not even know the geocoordinates of most of their assets (e.g. post boxes, post offices, delivery addresses). They do have a near perfect database of <i>what</i> these assets are, just not the coordinates. And that itself is useful. Knowing a postbox exists is a huge clue to geocoding it. Knowing a postbox has been removed from service is a huge clue.</div>
</div></blockquote><div><br>Actually, I think I was referring to ZIP codes (but you're forgiven for not recalling the details. ;-) ). The USPS *does not* maintain ZIP codes as polygon features, because the ZIP code is associated with a delivery *point* (i.e. a postal address). The Census Bureau combines those into something known as "ZIP Code Tabulation Areas", which are an approximation created by drawing boundaries around a collection of *points* that have ZIP code in common. Many other commercial vendors create something similar. But there is no official database of ZIP code polygons. <br>
<br>As to whether USPS has coordinates/geocoded coords for all of the postal 'furniture' out there, that I don't know. <br><br><div>-- SEJ<br>-- twitter: @geomantic<br>-- skype: sejohnson8<br><br>There are two types of people in the world. Those that can extrapolate from incomplete data.<br>
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