QGIS

Supporting the Folk

Ever since taking the dive into FOSS4G (Free and Open Source Software for Geo) I’ve always wondered “Can I do support?” and if you’ve remotely followed the business you’ve seen me float out different ideas for software support and mostly they’ve been rehashed examples I find from other companies and my past experiences with ESRI. That’s one of the main complaints from people “There isn’t any support” which is 100% wrong – there’s plenty of support it’s just different support.

The last two months found me providing QGIS and Geoserver support to two different companies. QGIS support really turns into the old 80/20 rule. 80% of the problems are commonplace and 20% are something I have to research. So far QGIS support hasn’t been that bad. I try to bill every 15 minutes and round down and overall it’s been somewhat fun.

Support Options

Geoserver was a whole different beast. I can get it installed and I can share out the common services quickly and easily. What I learned is there is a lot of flexibility built in that I didn’t know about. So research. Re-installations. Docker. Luckily this support contract was a troubleshooting/research oriented job – so a short duration and a lot of reading and learning.

My approach to support In my opinion has always been backwards. If you look at ESRI Support you buy “Whatever” and you pay maintenance for “whatever”. You get QGIS and you also get the width of breadth of about 3 different software packages. Geoserver you’re getting a lot of functionality and there is cross pollination with QGIS. So how do I make this worthwhile? Retainer basically. The support has to be different – and like I said above – half of the 80% were just data problems. Most of the time what was left was “you really need to upgrade QGIS”.

Anyway – excuse the lengthy babble on support. I end this all to say I’m probably going to make a push to do support on a retainer model. Spell out what I will and won’t do – and do what I can/can’t. I’ll help you with software, data, and tell weird jokes. You not only get Free software but you get an old guy with 30 years in the Geo field. Dang. 30 years. Well – that’s not quite depressing but it’s getting there.

QGIS Fun: Geometry by Expressions

One question last week: “Why don’t my buffers come out right in EPSG:4326”. That launched into an explanation starting off with “Well….the Earth is round…”. We ended up discussing the buffer tool and “surprise” you can’t easily buffer in EPSG:4326. You really need to learn about your local projections.

Of course I am wondering “Can you buffer in EPSG:4326 in QGIS?” I can do about everything else. Lets say you have points to buffer and they are WGS84, your buffer tool will complain about your data being in degrees (but it will run):

Notice the orange exclamation point next to degrees

If I were in a database (postgis) I’d use st_transform and shove my data temporarily into a local coordinate system and be happy…..but I’m in a desktop piece of software………..but – if you’ve worked with the field calculator any amount of time you’ve got a transform function that allows you to reproject data when using an expression. I also have a buffer function. I can also interact with the geometry of the layer.

QGIS now comes with a processing tool called “geometry by expression” that will allow me to use functions from the field calculator to work with geometry.

What is happening: I’m telling QGIS I want to buffer these points that are in EPSG:4326 10,000 Feet. Before I buffer them please shove them into EPSG:2274 so the 10,000 feet makes sense to me.

All that is left is to take my new layer and redefine it to 2274 – because I’m sneaking around QGIS’s nifty projection tools to create a layer with 2274 coordinates in a layer that thinks it should be in 4326. Confusing? A little – BUT – it’s possible. I could set this up in a model if I was going to do this constantly.

What did I tell the client? Reproject your data into a local projected coordinate system. What did I do – probably something I shouldn’t have BUT it shows how flexible QGIS has gotten in the last bit.

Hail Halloween

The TN 911 Project

So next week is the TN GIS meeting at Montgomery Bell State Park. Which will be the first conference I’ve walked into in 2 years and 2 months. I’m doing two things while I’m there – well three:

Walk a lot
Teach an OSM workshop
Give a talk on the 911 project.

So – the 911 project. I actually haven’t said much about it in a while. Well…..it’s gotten interesting.

Back in 2000 I did a talk on PostGIS day about how this had worked and by that point the project was about 2 years old. At that point I had talked to a lot of people in TN on the project and the general feel was that this was a lone wolf project – in other words no one else would want to use it. Plus I was getting a little anxious on how to grow it. I was even advertising it as a “server” – which yes it’s all housed in postgresql/postgis with QGIS as a front end.

So I did something weird and tossed it up on github and started working on it. Cleaning up code. Issuing tickets to myself and generally working. Out of nowhere Kyle Snyder came in and cleaned up some code. Now there’s two of us “doing things”.

So what’s the point? Well the point is I hope more counties in TN actually use it. I’m going to discuss it next week and show a running example. Basically at this point we just about have the TN NG911 standard 95% “running” as published in the manual. Hopefully by next week we have some instructions. I’ve got a few menus set up for QGIS. You get a ton of flexibility “out of the box”. Plus all this cleanup is going to be good for Henry County as I’ll use it to update what they have after some more testing.

The next big thing is I’ve been experimenting with PyQGIS and the discussion between myself and Kyle has been “what can we offload to QGIS and what does postgis do better?”. Do we set up QGIS to do address ranges on roads? Maybe we set up some pre-address or auto-addressing. Possibly that’s a processing toolbox thing. What if we work it all out and leave it as a PostGIS script? We’ll figure it out.

Anyway – It’s pretty exciting. It is a bit messy currently. Kyle’s teaching me about Github Projects. I’m explaining my insane ideas. We’re pushing and pulling all that we can. It is nice to dump all this out into the open for everyone to pick at – maybe someone else in the 911 “address maintenance space” finds it useful.

Need some help? Yell.

Exploring QGIS April 27th-28th 2022

So NRGS has a Exploring QGIS class coming up on April 27th and 28th of 2022. This is a gentle introduction to the the best FOSS4G desktop software you’ll ever use.

Here’s how it’s going to go:

Software: QGIS 3.22
Location: Virtual
Dates: April 27th -28th 2022
Two days from 12 to 4 EST
$175 – Register here!
Certificate for all attendees
Because it’s been just a bit – 20% off with Code QGISRocks

So what do we cover? A little bit of everything from the interface to processing, to editing, to making a map. It’s all recorded. It should be fun. Bring other data. Bring Questions. Bring a good sense of humor.

Can’t afford a ticket? Gimme a shout!

Come take a class and support the QGIS Project! To date we’ve pushed about 980 dollars US back to the QGIS Project.

QGIS, 3DEP, and You

I did a demo the other day for some foresters and I almost wanted to walk into traffic by the end of it. Not because of anything with QGIS and LiDAR – but I think I finally got “Virtual Fatigue”.

Part of the demo worked amazingly well. If you’re not familiar with TN’s LiDAR Program most (I think all) of the state is covered in free LiDAR. Yes Free. You can grab a county’s worth of LiDAR data and get to work. Here’s the other thing you need to know – it’s in zLas format. Yes – zLAS – the most annoying of the formats. I have to uncompress it using LAS Liberator. Then there is about 20 minutes of hoping I’m not at the corner of 4 tiles. It’s painful.

PDAL has been the engine that has been making LiDAR viewable in QGIS for a couple of versions now. I don’t tend to use it a lot (because I don’t do a ton of work with LiDAR) but when needed it it’s invaluable. For me the entire crunch of doing anything with lidar has been:

up to a 50 GB Download for an entire county
Conversion from zlas to laz
Define the vertical and horizontal projection of a tile using PDAL.

For the demo I wanted to do something “lidar” for a group of foresters to show them that FOSS4G works and we’re not just some weird hobby. I knew PDAL was being used on the backend of the USGS LiDAR Explorer but had not used it.

You can select an area (this is only for the US) and ONLY GET THAT AREA. I picked a pine plantation that had been partially thinned. I select the area using the interface. Choose my download format and PROJECTION PARAMETERS and then something cool happens. I generate a PDAL Pipeline JSON file and from the command line:

pdal pipeline process.json

I drag and drop the output of the above process into QGIS:

My life just got a lot easier and my blood pressure dropped like 10 points. LiDAR in TN is no longer a multi-hours scripted affair full of yelling. It’s literally pick what you want and then do the thing you want to do. QGIS gets easier. GRASS gets easier. Probably easier for the ESRI users also.

Anyway – check out LiDAR explorer from the USGS (especially if you’re in TN). It’s worth a few minutes of digging to learn about this tool.