Meeting with a City of Dallas GIS Analyst on Wednesday

Hackerspace Civic Hacking
#1

Hi folks,

One of the GIS analysts for the City of Dallas is having lunch with me on Wednesday. This is just a 1:1 event for me & him, but if any of you have ideas, concerns, or suggestions for the Dallas GIS department, let me know on this thread and I’ll pass them along.

The GIS (Geographic Information Services) department is responsible for collecting & maintaining geospatial data regarding tax parcels, zoning, thoroughfares, capital improvements, and all sorts of other things the government needs in order to make more informed decisions. As you can probably guess based on my Civic Hacking chairmanship, I am very interested in Open Data and would like to see more of it posted on existing portals such as https://www.dallasopendata.com/

As concerned citizens (or at the very least, people with app ideas), Open Data can give all of us the power to spot trends, make more informed decisions, and hold government accountable for their duties & promises. It can also reduce a city’s IT costs because applications can be developed by interested individuals at hackathons and open-sourced, rather than by some contractor likely to develop something proprietary that goes over budget and over time and is out of date before it’s even completely rolled out.

This is a great opportunity to establish a partnership for some really amazing & meaningful projects, so wish me well – better yet, share your thoughts & ideas here below, and then come to our next Civic Hacking meeting!

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#2

I wish you well, I cannot think of any requests to make to the GIS analyst.

It is my understanding that the Civic Hacking group wishes to take GIS analysis into our own hands for our own purposes. There is a lot of data out there, we just need to figure out how to get it and how to use it. Not to mention figuring out what it is we want to do with it.

When is the next Civic Hacking meeting?

At the last Civic Hacking meeting I said I would look into figuring out what businesses where around DMS, and I have found them in a database at the Dallas Public Library -> databases -> ReferenceUSA. You need to have a Dallas Public Library card to access it.

#3

It has been some time since I worked in this part of the country, but the metroplex used to have extremely high resolution (6" pixel) digital orthophotography, but its public use was highly restricted. Indeed they used to require the public to purchase the imagery at high price.

It would be interesting to know the most recent date available for such data, and what the current license terms are.

#4

North Central Texas Council of Governments (NCTCOG) sells these maps for the North Texas area.
http://www.nctcog.org/ris/GIS/aerials.asp

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#5

I see they still like the taxpayer to pay twice for this data.

#6

So it looks like it’d be around $3,500 to $4K to acquire all the imagery for Denton County alone. Not unreasonable for a municipality or business to pay, but certainly out of the reach of our little group. Nevertheless, that’s an intriguing resource; thanks for sharing!

I would tentatively plan on the next Civic Hacking meeting being 2 weekends from now, on Saturday May 30 after the Six Sigma class. Or, sometime during the week next week might be good (maybe next Monday or Tuesday). Let’s not meet on Memorial Day Weekend. I will go over the lunch discussion, plus we need to wrap up the design of the Makers Markers map. Anyone who is good with QGIS (or wants to see what it can do) is encouraged to come, as we will be hopefully finalizing the design and producing a file that can be printed on a plotter at a nice resolution.

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#7

This should help y’all more… BTW the USGS national map viewer is free.
http://nationalmap.gov/viewer.html

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#8

@mrcity said “Not unreasonable for a municipality or business to pay, but certainly out of the reach of our little group.”

That was my concern back in the day. The cities (and their taxpayers) already paid to have these images flown and processed. If you are a city member you have free access to the imagery data; however, the public that paid for it does not. I don’t know if their funding approach for the imagery has changed since I looked into over a decade ago, but their ‘fees’ haven’t changed much over that time so I doubt it.

If your intent is to acquire GIS data for projects for your group, I strongly suggest set-up up a Postgres/PostGIS database server to hold the GIS and thematic data. It works well with QGIS, ArvView, and GRASS and for QGIS at least will provide you’ll the means to do spatial queries that QGIS itself is not capable of making.

Also, if you haven’t looked at it, I strongly suggest looking at GRASS, it is an open source GIS package that has less emphasis on map making and much more emphasis on spatial and raster analysis.

#9

As I understand it, the aerial images which NCTCOG sells are prepared by private companies (see FAQ).

NCTCOG is a planning group which cities can choose to join or not. Presumably cities join NCTCOG because the value they provide is worth the subscription fees.

Because of mass purchasing, NCTCOG enables these cities to purchase these images at a lower rate than they could if an individual or city dealt directly with the private company. If a private citizen or company pays to acquire these images through NCTCOG, I don’t think that you can say they are paying “twice” to acquire these images.

#10

@amacha

Yes, that was what they said back when I first had an issue with this. At the time the Bruton center at UTD was organizing this. The problem I have is that this private company is contracted with and paid by a consortium of public entities to fly and produce these images–not simply to purchase something they produce themselves. Indeed at the time the public consortium provide specification that the private contractor had to produce the images to.

When I had someone look into the accounting for this, the cost the public agencies were paying should have covered that companies ENTIRE cost to produce these images. At least when I compare the cost to similar projects I have run for other municipalities across the country.

This is similar to a situation back in the mid 90’s when the City of Irving GIS department tried to charge me $6000 to acquire their parcel data base for use with a project I was performing for DFW airport. In that case, our client was willing to have lawyers remind them that state law only allowed them to recoup their costs for copying the data. BTW, we had a quote of over $50,000 from the Dallas County Appraisal district for a similar set of PUBLIC data.

The client when I was dealing with the digital orthophoto issue was not willing to involve lawyers. So they just paid for the data. It just annoyed me since the data was produced with public tax dollars.