QGIS 2.0.1. missing Google Mercator CRS

QGIS 2.0.1: Where’d Google Mercator Go? (And How to Get It Back!)

So, you’re firing up QGIS 2.0.1, ready to bring in some of that sweet, sweet Google Maps goodness, and… wait, where’s Google Mercator? Don’t panic! You’re not alone. This little head-scratcher has tripped up plenty of folks since the release. The good news is, it’s not really missing, just hiding under a different name. Let’s get you sorted out.

CRSs: The Rosetta Stone of GIS

Think of Coordinate Reference Systems (CRSs) as the Rosetta Stone of the GIS world. They’re what let your map talk to the real world, translating those X and Y coordinates into actual places on Earth. QGIS? It speaks thousands of these languages.

The “Missing” Google Mercator: A Case of Mistaken Identity

Here’s the deal: QGIS 2.0.1 doesn’t shout “Google Mercator!” from the rooftops. Instead, it’s hanging out incognito as “WGS 84 / Pseudo Mercator,” or if you’re into code, EPSG:3857. Yep, that’s your Google Mercator right there.

The Fix: When you’re hunting for it in the CRS selection box, type in “WGS 84 / Pseudo Mercator” or “EPSG:3857.” Problem solved!

Basemaps and the Crashing Conundrum

Okay, so finding the right CRS is half the battle. The real reason you’re probably here is to add a basemap, like Google Maps, right? And maybe you’ve run into a brick wall of crashes using the OpenLayers plugin. I’ve been there, trust me. Even with “on-the-fly” reprojection enabled, things can still go south.

Let’s Troubleshoot Those Basemaps (and the Crashes!):

• “On-the-fly” to the Rescue: First things first, make sure “on-the-fly” CRS transformation is actually on. It’s the magic sauce that lets QGIS juggle layers with different coordinate systems. You’ll find it under Settings -> Options -> CRS. Tick that box!
• QuickMapServices: Your New Best Friend: Ditch OpenLayers for a bit and give the QuickMapServices plugin a whirl. It’s generally more stable and gives you access to a bunch of different basemaps. Seriously, it’s a lifesaver.
• Preload Power: Try preloading some vector data from your area of interest. It sounds weird, but it can sometimes prevent those pesky crashes. Think of it as giving QGIS a little something to chew on.
• Transformation Troubles? Sometimes, the issue isn’t the basemap itself, but a conflict with another layer, especially raster images. Restart QGIS, open your satellite image or other layers first, and then add the next one to see if it causes the crash. It’s a process of elimination, but it can pinpoint the culprit.

Rolling Your Own: Defining a Custom CRS

Feeling adventurous? If you need a CRS that QGIS doesn’t offer out of the box, you can actually create your own. This is a bit more advanced, and you’ll need to get cozy with the PROJ projection library.

Here’s the DIY Approach:

Project vs. Layer: Know the Difference!

One last thing: keep in mind that there’s a difference between your project’s CRS and the CRS of your individual layers. Your project CRS is the overall coordinate system for your map, while each layer has its own. QGIS is pretty good at reprojecting layers on the fly to match your project CRS, which is super convenient.

A Word of Caution About Google Mercator

While Google Mercator (EPSG:3857) is popular, it’s not perfect. It treats the Earth as a sphere, which introduces distortions, especially the further you get from the equator. For projects where accuracy is paramount, consider using a local projection or UTM.

The Bottom Line

So, the “missing” Google Mercator in QGIS 2.0.1 isn’t really missing at all. It’s just rocking a different alias. Once you know where to look, and you’ve got a handle on those basemap troubleshooting tips, you’ll be back to mapping like a pro in no time!