Esri’s ChangeMatters site gone?

For several years now, I’ve been using Esri’s ChangeMatters site to help students get an early taste of the power of remote sensing.  They get excited about the ways in which we can use the long history of satellite imagery to do science, and, let’s face it, look at cool pictures of the earth.

For those who haven’t tried it, it looks like this:

Image result for esri change matters

You simply choose a date range, and an image type (IR, true color, etc.), and watch the magic happen.  The third pane displays vegetation change.  You can move the map in any of the panels, and the other two update.  My students are tasked with finding a place of interest to them, noting the changes, and then doing a little digging to find out what event(s) caused the change they see.

So this week, I trot out my trusty assignment, and students immediately let me know that the site is redirecting them to something else that doesn’t seem to do what I’m asking them to do.

The original link,, now redirects to a page with some beautiful imagery and a swanky new interface.  Visitors are encouraged to “Try it live”, and that button takes you to a page with four options, Landsat Viewer, Landsat Explorer, Arctic Landsat Viewer and Antarctic Landsat Viewer, which are bewildering to the geospatial novice.

For my purposes, since I wanted students to look at images side by side, I chose the Landsat Explorer option.  It features the Swipe interface, which I didn’t see in the Viewer (if I missed it, apologies, but I was trying to quickly push out new instructions for my class).  Here’s the quick and dirty update I cobbled together for my students; hopefully it will help some of you who have suddenly discovered you need to update your assignments as well.

If you are using the old link, and get redirected, click Try it live, then select Landsat Explorer.

The new link is  (If it takes you to a story map, scroll all the way to the end until the toolbar pops up on the left.)

  1. Enter a place you’d like to view in the upper left.
  2. On the tools on the left, select the wrench.  Set the rendering to Color Infrared.
  3. Next, click the clock to set a timeline.  Set the date you want for the first image, then click the little blue arrow in the upper right of that box.  Set the date for the second image.
  4. Right below the clock button is the Swipe tool (looks a bit like the elevator door symbol).  Click that and you’ll get a divider in the middle of the screen that you can swipe back and forth and look at the changes – you’ll see the first image you picked
  5. If you want to look at different bands, set the renderer (wrench tool) to the bands you’d like to see, then reset the timeline.

Unfortunately, this site seems to have a less complete image set, so you may have to do a little exploring to find a place that has imagery for multiple dates.  If you’re not finding stuff, try setting the cloud filter a little higher (not too high, or you’ll get nothing but clouds!).

Spend some time exploring, then continue on with the activity prompt.


Hacking the Firefly Basemap

Related image

John Nelson, the name to know in Firefly Cartography, has been making these eye-catching gems for probably a decade now.  And, true to form, he’s always trying to find ways to make them more accessible to anyone who wants to make them.

Toward that end, he released a nifty Firefly Basemap Starter Pack a short while back, and my students were overjoyed that they could simply download the ArcGIS Pro project file, skip all that imagery gathering, desaturation stuff and get right to the fireflies.

Enter disappointment.  Whether it is something to do with our IT configuration here on campus, or student file management skills, many of my students found that the basemap project was cantankerous, losing data sources or just plain not displaying.  Every time they sat at a new computer to work on the project, they had to re-download the project file and then rebuild their maps.

So, to make their lives (and mine!) easier this semester, I set about hacking John’s project.  Many years ago, when he was still keeping the firefly technique for his own personal glory, he introduced a blog post on Severe Satellite Basemaps, which the savvy reader will spot immediately as the foundations for the firefly technique.  This post details downloading Blue Marble images from NASA and desaturating them, for a dramatic backdrop to your data.

I’m generally a pretty lazy person, so rather than wade through all of those beautiful images (they’re a glorious place to get lost), I figured I’d just ride John’s coattails and dissect his Pro project instead.  This way, he’s done all the hard work of collecting the images, setting up the layers and customizing them, and I can simply bask in the sunlight of having fewer student issues, and also tricking them into working a little harder for that firefly-y goodness.  (See, John? I can make up words too!)

So, if you’re having some challenges with that Pro pack yourself, or you just want a little peek into John’s genius/madness, here’s how to do it yourself:

Getting the Goods

Grab that starter package from here.   Because of our IT policies, we’re still in Pro 2.2, so the Open in ArcGIS Pro option doesn’t work for us, but the Download option does.

Simplify your life, or at least your Contents pane.  John built in some nifty, scale-dependent layers on the side, and as you zoom in and out, you’ll notice that only one of these displays at a time.  Zoom to the level that you want for your basemap, identify which of the groups (0-5) is displayed, then remove the rest of them, just to make life less confusing.  My students will be working with data for North America, so I zoomed in there, which turned out to be group 2, given my screen size. YMMV.

Get coordinated.  In my map, although the map frame is displayed in Web Mercator, the individual image tiles all act like they don’t know they have a coordinate system, so exporting the raster layers proved a little tricky.  So, I exported the vector layers first, because they’ve got it together, and will export as WGS 1984.  Once you export one of them and let Pro add it to your map, the raster export tool will now let you choose that layer as a CS for the raster export.

Only take what you need.  If you look closely, you’ll see that Coast and CoastGlow are the same layer with different symbology treatments.  Same for LatLongOceans and its glowy counterpart.  So just export one of each, and then you can reuse them in your new basemap (more on that later).  Same for the Color and Black and White imagery layers – they’re just duplicates, symbolized differently.  I also poked around to see which tiles were displayed in my North America extent, and chose only to export those couple of tiles, but choose whichever ones are visible in your extent, or take them all.  It’s your disk space.

To vignette or not vignette?  The vignette effect is pretty subtle, but can be pretty cool.  In my chosen extent, it barely shows up, so I decided not to export it, but you do you.

You should now have all the layers you need: a Coast layer, a LatLongOceans layer, a set of image tiles, and optionally, vignette layers.

Putting it all back together

Here’s where I reveal John’s secrets.  For reassembly, I recommend a fresh Pro project, just to get rid of any lingering whatever that caused my students such grief.

  1. Set your map frame background to Black.  (This is also a great time to set your display CS – see previous post on Projections and their misuse.)
  2. Bring in your image tiles, and group them.  Name this group Color, and set it to 80% transparent
  3. Copy the Color group, and paste it into your map frame.  Rename it Black and White, and move it to the bottom of your layers.  Set the group to 30% transparent.
    1. Set the Symbology for each layer in this group to Stretch, and use the default grayscale ramp.
  4. Add in your LatLongOceans layer.  Symbolize as Unique Values, using the field DEGREE5.  Remove all values, then add back in just the Y value.
    1. Change the symbol to something bright blue (although an orangey-yellow can look pretty cool, too), set the line weight to 0.5pt and the layer to 80% transparent
  5. Copy LatLongOceans and paste it into your map frame.  Rename as LatLongOceansGlow and move it underneath LatLongOceans.
    1. Adjust the line weight to 5pt and the layer transparency to 95% transparent
  6. Add the Coast layer to your map.
    1. Set the fill color to No color and the outline to Sahara Sand, 0.5 pt, and make the layer 75% transparent.
  7. Copy Coast and paste it into your map frame.  Rename as CoastGlow and move it underneath Coast.
    1. Adjust the outline to 3 pt and set the layer to 95% transparent.
  8. Optional: Add in the vignette layers.  These should already be suitably transparent, but feel free to adjust.

And there you have it.  You should now have a a snazzy but low-key basemap ready for firefly-ification.

With thanks to @John_M_Nelson for allowing me to ruthlessly dissect his contributions!


Projections, or enabling a Flat Earth

Projections are a hard concept for students.  Fundamentally, they understand that to represent the round earth on flat paper (or a flat screen), something’s got to give.  We talk about developable surfaces, and distortion, and why it’s important to project data layers correctly for analysis and visualization in our foundations course, and in almost every course after that, there are a number of students who still seem to miss the point.

“But my GIS software just draws everything together, regardless of projection, so why does it matter?”

“But I projected my data, why does my map still look wrong?”

“But it is projected – it’s in WGS1984!”

I will never have the deep understanding of projections that my NACIS colleagues Bojan Šavrič and Tom Patterson wear like a badge (or at least a t-shirt).  But projections are a fundamental part of what we do as spatial researchers and cartographers, so everyone needs to know at minimum that choosing the right projection is important to measurement, navigation and aesthetics.

How do we teach students about projections and why they matter?

There are some fun videos out there that cut up globes, or flatten oranges, which gets them thinking about the challenges of representing the round earth on a flat surface, but not so much about the distortion in a specific area.  Others have projected the human head in multiple ways, to help them understand the distortion, but mostly students wonder why the heck you’d do that, because they are obviously all wrong, rather than understanding the relative strengths and weaknesses of each projection.

They seem to get the idea that distortion happens, and that we mainly want to control it in our area of interest (also known as making it somewhere else’s problem).  But they’re not quite to the point of making a solid connection between why you’d use one particular projection over another.

How do we get students to think about choosing the right projection for the job?

This is a trickier question, and I’d love to hear what the rest of you are doing.  I used to use one that outlined a few scenarios for students to create a basemap (e.g. need a map of the Andes region that preserves shape, or need a map of the contiguous US that preserves area), and have had mixed results.  Often, students are trying to use projections designed for the whole world, and then just moving a central meridian or standard parallel.  Not unworkable, just not ideal for areas smaller than a continent.  Recently, I switched to a small multiples version, using the same country (China) throughout, and having them thoughtfully compare 6 different projections, modified for that part of the globe.  Initial results look promising, but we’ll see if that carries forward into other assignments where they have to decide for themselves how to flatten that part of the earth.

Obviously, #notallstudents.

We have some fantastic students who come through our program and win awards and go on to do great things with maps.  But I want to reach a larger percentage of them, and I want to stop looking at maps of the US in Web Mercator.

I understand if you nodded off somewhere in the first paragraph.  If you made it this far, thanks for reading what amounts to a little bit rant, a little bit call for help.   I’d love your thoughts on how you teach projections.


Here are some resources I’ve been sent since posting this (more as they are suggested):

Define Projection or Project?, a nice post that adds some clarity on the Define Projection tool in ArcMap/Pro by Heather Smith

A nice post (with hand-crafted artwork!) on coordinate systems, with a side order of Plate-Carrée, by Lyzi Diamond



The first week in Pro, it’s a doozy!

Let me start with a little context: In our program, we want to prepare students for as many types of GIS environments as we can.  So, we start them out in ArcMap, which still has a strong fanbase, then expose them to Pro in a couple of courses, and multiple open source options in the later courses.

The students have been in ArcPro for about a week now, and for most of them, it’s the first time they’ve touched this shiny new version of ArcGIS.  It’s a tough slog.  By this point, they have two or three other geospatial courses under their belts, enough to start really feeling comfortable with ArcMap, and now we’re asking them to remember all the concepts, but chuck out most of the techniques they’ve learned.

It’s a bit like getting into a rental car and not being able to figure out how to work the windshield wipers, but all the time, with everything they’re trying to do.  They know the button is there somewhere, but nope, that’s the cruise control – oh, there it is, now does it go up or down?  Fortunately, crashing ArcMap seldom results in lasting injuries.

So I start them out with a heavily step-by-step introduction to both the interface and map design principles.  (Shameless book plug: Chapter 2 closely resembles this lab.  Link below.)  Here are the places where they often stumble:

  1. Creating a new map.  I provide a starter project (.aprx) file for them to get them past the first obstacle of having no map at all, as this is almost always bewildering to users of ArcMap who are accustomed to having a map window pop up right away, and instead get a dashboard of stuff they don’t know how to process.  We’ll deal with that particular balrog in a future lab.
  2. What is this “stuff” in my new map?  When you insert a new map, you get a complimentary set of layers that, frankly, I don’t know why you’d want.  There’s a setting in the Options where you can set the default basemap to None, which I did immediately on my own computer.  I don’t need someone else’s base layers in my map, and we prohibit students from using pre-designed layers in this class anyway, since it’s all about them learning to design their own stuff.   But guess what?  That setting doesn’t stick when you’re in a laboratory setting, so every time they log into the computer, they have to do that again (or delete layers from every new map).
  3.  Folder connections don’t stick.  They’re a little bit used to this, as even in ArcMap, the connections went away when the computer profiles reset (in our case, every night), but in Pro, every time you start a new project, you have to make new folder connections, even on your own computer.  The folks at Esri have provided some very plausible reasons for this, relating to organizations that have 8,000 years of folder connections stacked in their Catalog window, but I find it frustrating.  I’d prefer something like a setting in Options, or even something IT policy could determine, like a “keep alive” setting that disconnects them after x days, or x days of non-use.  Anyway, you need to remind your students to make folder connections every time they open Pro (which is sometimes a lot with new users who may rage quit, or opened the wrong lab project, etc.).  Also, trying to coast without them often results in empty results when browsing for data.
  4. OMG, my map is gone! Translation: I’ve added a Layout, and it’s empty.  I actually love this, because it means I can make multiple layouts in my project, and pick and choose which maps go in which ones, which is super awesome, and thanks so much to the Pro team for adding this one 🙂  However, for ArcMap users used to flipping over to Layout view and finding all their data frames there in a heap waiting to be organized, it’s a little traumatic.  So, you’ll want to prepare your students for this.

For us old dogs who have been using ArcMap since the dawn of time, there’s also the challenge of troubleshooting in Pro.  It crashes less often, but there are some funky little things (like the empty folder windows noted above) that only crop up when you have 30 students doing things 30 different ways and pushing buttons you’d never think of pushing yourself.

If you’re teaching in Pro, I’d love to hear your top stumbling blocks with students in the comments.

Happy mapping!

Disclaimer: One of the key components of this blog will be talking about teaching students in ArcGIS Pro, and the conversion from ArcMap to ArcPro as a coordinated effort across our program.  I receive no compensation from Esri or its affiliates for these posts, but I did write a book last year called Mapping with ArcGIS Pro, which you might find useful if you’re starting out with maps or ArcPro.

Teaching Cartography

It’s the start of a new year, when we’re supposed to start new things, right?  Okay, technically we’re in the second month already, but the first weeks of the semester are always a little hectic, so here we are.

I’ve been encouraged by my peers to get a blog going about things related to the way I teach cartography, common things students struggle with, etc.  There are lots of great blogs out there on the general condition of maps, some insightful (and sometimes pithy!) critiques, and some that are just showcases for maps old and new, good and bad.

Here are a few of my favorites:

(this list could go on for days, so I’ll just stop now and mention others as they are relevant to the topic at hand)

This is not one of those blogs.

For starters, all of these people have spent time and care choosing a blog template that works for their style, and in some cases is a work of art in itself.  After months of browsing templates in a deliberate attempt to delay starting this process, I have elected to go with a pretty basic look.  Clean, we’ll call it.  Classic.  Yeah, that’s it.

My intention here is to share some of the challenges faced by novice cartographers, and hopefully some good advice for others out there who are transferring this time-honored skill to others.  In particular, I want to create a subset of posts specific to using ArcGIS Pro, as using that software in a lab setting is very different than using it on your own machine.

So welcome, and I hope you’ll drop in occasionally.  If you’re a fellow educator, I look forward to your responses to future posts to see how you do things.