Comments for Alastair Aitchison

Comment on Loading Ordnance Survey Open Data into SQL Server 2008 by Factivism | Voice of the DBA

Factivism | Voice of the DBA — Mon, 29 Apr 2013 17:53:09 +0000

[...] along the way. By showcasing your knowledge of data in some way, perhaps even explaining how to load the data, you get experience and practice in both a technical area, as well as in communicating your [...]

Comment on OGR2OGR Patterns for SQL Server by alastaira

alastaira — Fri, 26 Apr 2013 05:38:56 +0000

Hi, that error simply means that the command prompt can’t find the OGR2OGR program. You either need to get your I.T. department to add the location of the ogr2ogr executable to the command path, or you need to use the “cd” command to change into whatever directory OGR2OGR was installed into (e.g. cd c:\Program Files\OGR2OGR) but if it was installed on a server for you, you’ll likely not know where that is.
Yes, OGR2OGR will create tables for you.

Comment on OGR2OGR Patterns for SQL Server by Ryan W.

Ryan W. — Thu, 25 Apr 2013 22:08:13 +0000

Hello

When I run the following code:

ogr2ogr -f “MSQLSpatial” “MSSLQ:server=SQL\SENEXSQL1;database=ESRIShapefilesDB;trusted_connection=yes;” “tl_2010_us_zcta510.shp” a_srs “ESPG:4269″ -lco “GEOM_TYPE=geography” -lco “GEOM_NAME=geog4269″ -nln “tblUSAZCTA” -progress

I get an error saying ‘ogr2ogr’ is not recognized as an internal or external command, operable program or batch file. I know this is a simple problem but I have little experience with command line prompts. IT installed the software on our server a couple of days ago so I don’t understand the error. Any ideas of what is causing this problem? Also currently the “tblUSAZCTA” table does not exists in the database. Will this script automatically create the table?

I recently brought your book. Thanks in advance!

Regards,

Ryan

Comment on The Google Maps / Bing Maps Spherical Mercator Projection by The Google Maps / Bing Maps Spherical Mercator Projection | :nine

The Google Maps / Bing Maps Spherical Mercator Projection | :nine — Tue, 23 Apr 2013 05:21:19 +0000

[...] The Google Maps / Bing Maps Spherical Mercator Projection – very good explanation of EPSG/SRID codes as they relate to using google or bing maps [...]

Comment on The Google Maps / Bing Maps Spherical Mercator Projection by Guillermo Biot

Guillermo Biot — Sat, 20 Apr 2013 00:02:28 +0000

Hi alastaira, thank you very much for your answer. I agree that 18m is not a big deal, maybe it’s a matter of precision, but as you comment, a third source matches exactly one of them. Indeed the GIS software I use also matches the bing maps location, so I would dare to say that google maps is wrong by 18m, I wouldn’t expect that “error” from google maps. I tried different positions around that area and all of them have the same amount of offset in the same direction (always East, North is correct), it’s not just random. I found out that this missmatching doesn’t take place in other cities that I checked and maybe it will be corrected on the next render/process of the google maps tiles. Do you think it would be worthy to notify the people working on google maps?

The big deal was that the missmatching was driving me crazy because I was using the lat/lon coordinates from google maps in that area and they didn’t match my maps on the GIS software. Obviously I thought the problem was at my side, on a datum translation.

Thank you again for your time.

Regards,

Guillermo