[Talk-us] MassGIS Building Import Start

[Paul Norman]

A couple of initial comments: 

 

Has some kind of simplify been run on the data? Although most of the
buildings are quite good some of the curved ones are overnoded (e.g.
http://took.paulnorman.ca/imports/massgis/noded.png)

 

If your documentation conflicts with the requirements of the import
guidelines
(http://wiki.openstreetmap.org/wiki/Import/Guidelines#Use_a_dedicated_user_a
ccount) around a dedicated account it may lead to people importing your data
getting blocked.

 

You've asked for a check of the reprojection in the data directory but I
don't actually see a data directory anywhere. Could you provide a link?



From: Jason Remillard [mailto:remillard.jason at gmail.com] 
Sent: Wednesday, December 12, 2012 5:15 PM
To: talk-us at openstreetmap.org; imports at openstreetmap.org
Subject: [Talk-us] MassGIS Building Import Start

 

Hello Everybody,

 

I would like to kick off the MassGIS building import. This following is
copy/paste from the current wiki (
http://wiki.openstreetmap.org/wiki/MassGIS_Buildings_Import). The external
links will work on the wiki.

 

--------------------------

 

On Dec, 2012  <http://wiki.openstreetmap.org/wiki/MassGIS> MassGIS released
a high quality data layer for all
<http://www.mass.gov/anf/research-and-tech/it-serv-and-support/application-s
erv/office-of-geographic-information-massgis/datalayers/structures.html>
buildings in the entire state of MA. Previously
<http://wiki.openstreetmap.org/wiki/MassGIS> MassGIS only had buildings for
Boston and its nearby suburbs.

The plan is as follows.

Source Data License

All  <http://wiki.openstreetmap.org/wiki/MassGIS> MassGIS data is in the
public domain. See  <http://wiki.openstreetmap.org/wiki/MassGIS> MassGIS
page, and talk-us
<http://lists.openstreetmap.org/pipermail/talk-us/2012-December/thread.html>
archives for detailed discussion. A previous (incomplete) version of this
data that covers the Boston area has already been imported.

>From the MA Secretary of state Office
<http://www.sec.state.ma.us/pre/prepdf/guide.pdf> Frequently Asked
Questions, first question is

What records are public?

Every document, paper, record, map, photograph, etc., as defined by law,
that is made or received by a government entity or employee is presumed to
be a public record

>From the MA Secretary of state
<http://www.sec.state.ma.us/arc/arcres/residx.htm> Duplication Services,
last section.

Records created by Massachusetts government are not copyrighted and are
available for public use. Copyright for materials submitted to state
agencies may be held by the person or organization that created the
document. Patrons are responsible for clearing copyright on such materials.
For more information on copyright law, please see the U.S. Copyright
Office's web page at lcweb.loc.gov/copyright.

Scripts

A script was written to convert MassGIS shp files to OSM file. Each town has
its own zip. Inside of the zip is two OSM files. The first file has all of
the buildings, the second file has only the buildings missing from OSM. This
has been completed, data is
<https://docs.google.com/a/twincoastmetrology.com/folder/d/0B6HixOxli_6ldGVk
REtxdk5lWGM/edit> here. jremillard will update these files. The scripts used
for the shape to OSM conversion are also at the same link as the data.

Status Tracking

A google docs
<https://docs.google.com/spreadsheet/ccc?key=0Ar0iC0thXzOjdFc4c3diOGZiNlNtX2
ZoOVNacTE3R3c> spreadsheet will be used to track progress on each town.
People helping with the import will be able to claim a town, mark as town as
already building complete, or mark it as "skip" for the final automated
import because of data problems.

Who Is Doing This

So far OSM users ingalls and jremillard are working on the import. We will
work on getting as much help as possible.

Getting Help

Use the MA osm database extract to get a list of users that have added 10 or
more buildings in 2012. We will contact these users and ask if could help
with the import. Not completed.

Manual Imports - Step 1

It is expected that users doing the town by town import will use their
normal osm accounts. The
<https://docs.google.com/a/twincoastmetrology.com/folder/d/0B6HixOxli_6ldGVk
REtxdk5lWGM/edit> data will be download into JOSM, visually inspected,
fixing any problems, then uploaded.

Schema

The OSM files that are in the ZIP file will only be tagged with
building=yes.

The MassGIS building STRUCT_ID will not be included. First, MassGIS made no
attempt at preserving the STRUCT_ID when they updated the data set to
include the entire state. The MassGIS STRUCT_ID, is based on X,Y centroid,
when they updated the building locations, all of the ids changed. Second, No
actual scenario came up in the discussion on why somebody might want to link
the OSM structure back to the MassGIS data. In fact, nobody could come up
with a case where previous imports that did include the original id turned
out to be useful to somebody. Thirdly, if somebody really, really does need
to link the OSM building to the MassGIS source layer, they can always link
them them based on the building centriods of the two sets, and to get even
more precision, rolling the change sets back to the import time and doing a
more exact match will always be possible. Basically, the STRUCT_ID is
redundant with the actual building geometry. Lastly, including the STRUCT_ID
is not free. It will be confusing to future mappers. What to do with the
STRUCT_ID, when a building is moved, deleted, or copied/ pasted? The wiki
will not have this tag documented, it will not be clear what it is for. If
even one fix is not made because of confusion over the STRUCT_ID tag, we
will have lowered the final quality of the map for no apparent benefit.

Credit

Credit to MassGIS will be included in all changeset comments. It will read
as follows Building Structures (2-D, from 2011-2012 Ortho Imagery) - Office
of Geographic Information (MassGIS), Commonwealth of Massachusetts,
Information Technology Division. No source tag will be used on the buildings
themselves. See
<http://lists.openstreetmap.org/pipermail/talk-us/2012-December/thread.html>
talk-us archive for a discussion. By including the credit in the change
comment, it does not need to be managed by future mappers who will be
correcting/improving on the data. For the people that want to know where
specific data came from, the change history on the way will have all the
needed information.

Automated Import - Step 2 - Project Completion

Sometime after May 2013, the towns that have not been imported by hand or
marked as "skip" will be imported directly by an automated script. This
automated script will done under its own account. This script has not been
written yet.

-------------------------

The import has been added to the catalog page. 

 

Omitting of the source tag, and massgis::id tag have already been discussed
in talk-us. People where going both ways, but I would like to skip them at
outlined above. However, we need help more than we need to get our way! If
you feel strongly about the id and source tag, sign up to import a bunch of
towns by hand and we can be made to change coarse.

 

The user account has not been discussed yet. I am hoping to get some
guidance. We are planning on using our own accounts on the "hand" imports.
The automated import at the end of the project will get its own account,
which I think is intention of the import guidlines wiki. If this is not
acceptable, and we in fact do need our own account for each hand imported
town, I will make a new OSM account, and give out its password out to
everybody that asks for it to do the import. 

 

The last area I would like some help on. Could somebody look at the script
in the data directory and verify that the MassGIS datum was correctly
converted to the OSM datum. The output data is well aligned visually, but I
have been warned in a private email that messing this up will results in < 1
meter error, which may not be apparent with a visual inspection.

Thats it!

Jason

 

 

 

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