You can make that map!
Have you wanted to fly Wings of Glory over a basemap of your very own home? Or have a historical landing ground as the battle ebbs and flows? Yes, there's some great terrain and maps out there and with this primer it will show how you can find that terrain for a basemap, so fill your inks and get your printer ready!
Hello, Capt Moonbeam at your service. I make maps day and night, and for fun as well! And here's how you can too. In this how to, we'll install software called "G I S", interact with data service; and if you like download 'big data' and make it map ready. I also use this tool to bring in photos and scale them to the ground, like the model of the Möhne dam being game-ready for your Dambuster. What you want to map is up to you!
Getting started. You'll need a computer that can fire up good graphics, as you'll be running a G I S - Geographic Information System - called Quantum GIS (known as QGIS). This is an open source tool developed by many online users, is free, and allows access to a wide range of data.
You'll have a tool like your favourite Earth exploring viewer, except now you can control what you want in your map! No more cut and paste screenshots, as you'll tap into the very satellite data. The best bit is you control the scale of the map - zoomed in for straffing, zoomed out for dogfights, and a bit more for high-altitude work. More on scale later.
Because QGIS is always being developed, I can't say which version to use. However, look for the "most stable" release that matches the capability of your machine.
https://qgis.org/en/site/forusers/download.html
Once installed, the way to look at the screens is you have a map view and a map layout or composer. The composer is the thing you'll get printed out, so thinking what size you can print.
And where's the satellite map you promised, Moonbeam!?!
Here it is. In QGIS 3 versions, you'll need to find your Browser layers. You may have to open it by selecting, from the top - View / Panels / Browser. You'll see an "XYZ Tiles" and here's where the fun begins. Right mouse click for a new connection.
Then type in the URL place your favourite map path. At present (20200509) the connection is http://mt0.google.com/vt/lyrs=s&hl=en&x={x}&y={y}&z={z}
Terrain, or relief, is
http://mt0.google.com/vt/lyrs=t&hl=en&x={x}&y={y}&z={z}
as sometimes a map with a hint of transparent terrain looks more rugged and in 3D.
You can now control the world at your fingertips!
In QGIS 2, it's slightly more fun. Open up the Plugins/Manage and Install Plugins ...
In QGIS 2 versions, the plugin is OpenLayers, and will be Web / OpenLayers. However, the tool may be broken, or need some special file. That's the other side of open source, always improving.
Now to make a map that can be printed.
First you create a layout - the guts of what you're looking for. Under Project / New Print Layout ... or in older versions of QGIS Project / New Composer ... a piece of virtual paper turns up. We'll add our map to this, and it will be the thing we send to the printer.
To change the page size and orientation, right mouse click to Properties / Item Properties and the options should be on the right of the page.
To see the map, Add Item / Add Map - and drag over the page. To check the correct scale, in the Items under the Item Properties, look to the Main Properties and select the scale you like.
"Drag boxs" appear on the map, for you to resize the graphic. If you want to move the content, select Edit / Move Content. If you want to reposition the frame, select Edit / Pan Layout. It takes a while to get used to, but it'll work :-)
Then you can save your layout or composition to a file type, and have it printed! [I'd like to have a shout out to Dario Calì for the fantastic maps you make, my method here is nothing compared to your inspirational maps!]
Scale! About scale - there's often questions in the forum about what scale to use. I looked at the size of Buckingham Palace on the target card and compared the size of the actual building, and came to a scale of 1:11,880. You may get a different value, but that scale allows me to have a Dornier's eye. So at the bottom of your data view, select the scale that works. Yes, the data may be pixelated, but the trick here is when you save the composer/layout file through an image manipulator's filter to smooth, blend, and sharpen those areas I want.
Now to add something special - more imagery!
For a Dunkirk map I used the standard background world map, but to blur modern details and extend into the Channel a bit I overlaid a dataset from "Sentinel-2" - this is where it may get tricky. Sentinel-2 is a fantastic platform of the European Space Agency that has resolution of about 10 metres, but you will need to blend the data layers to create your satellite image. Here' how!
There are a range of data downloaders, but the one I prefer is from the United States Geological Survey (USGS) "EarthExplorer." https://earthexplorer.usgs.gov/ EarthExplorer requires a free registration, but then you can zoom to where you want data. EarthExplorer has a handy tab system to get data. 1. select the map area "Use Map" or put dots where you want. Then, 2. select your data. I use Sentinel - Sentinel-2, but you could use others.
My top 10 tip for EarthExplorer: it goes from the International Date Line across the world to the International Date Line - you can't cross it. So if you go from Hawai'i to Henderson Field, ya have to go the long way ...
Then press "Results" which appear in your 4th tab. Now we look for an image that fits our needs, time of year [snow] or with lots of clouds. You can also filter on how much cloud you want in the setup. A fun one data source is the Declassified data but there's a shopping trolley with a fee attached; so I've used the Sentinel-2.
A note of caution the Sentinel-2 will cover an area much larger that you want. Or, your area is in the middle of two images. That's generally where most wars are fought, on the join of four mapsheets. As each scene can be quite large compared to a standard aerial image, do check the "Browse Overlay" Want realistic clouds? They'll be there. So select what looks good for you. At any time you can go back to tab 1 Search Criteria for another area, or and choose another tab 2 Data Sets, to get the right area and your preferred data. Then you're ready for download.
It may be a pain, but for best results download the larger file size from the formats EarthExplorer returns.
They'll be WinZipped up, so unzip them and put it into a new folder. The files to display in QGIS are in a folder called "IMG_DATA" along way down the directory tree, the files we want are wheelbarrow_B02.jp2, wheelbarrow_B03.jp2, and wheelbarrow_B04.jp2 - where wheelbarrow is the big long file name!
The breakdown of the wheelbarrow, name, is the location of the scene in a mapping format (called Universal Transverse Mercator, or UTM for short), and the time it was taken at Zulu time.
The beauty about this data is I can choose what image I want, when I want; summer or winter, and with interesting clouds or clear blue sky.
Now for some crunching. Sentinel-2 sees parts of the spectrum we see as coloured light as "bands" of red, green, and blue. We have to add those bands to QGIS and use the Raster Calculator to recombine them to make a single layered image. Add the ..._02, ... _03, and ..._04 files. These are the blue, green, and red bands. Open the Raster / Miscellaneous / Merge
The merge tool can look different between versions, you're looking to add the files
at the [...] button.
Select the three file the _B04.jp2, _B03.jp2, and _B02.jp2 files, and select either Layer Stack or "place each input file into a separate band." I go back through the filenames of the layers added, and change _B04 to _B02, and _B02 to _B04; or make the layer _B04 come first and _B02 last. That puts the red, green, and blue files in order for the layer stack. You can also make the file as a virtual file, but I like to save these files for another time.
The end result has to be a .TIF file, so I like to save it with as the same filename as a .JP2 file, but then save as _RGB.tif.
And let it run! You should have a colour image to view.
if it doesn't look right, open the layer's properties (right mouse click) on the layer name in the layer list, and change the symbology from red to blue, and blue to red. That usually works :-)
Once I've made my map and exported it as a TIF file, I like to do some smoothing in a tool like GIMP or IrfanView, especially to sharpen up some areas or smooth out others. A filter I like is the blur, which I think makes a product not so edgy and brings attention to the planes that fly over it.
If you've got an aerial photo, like a reconnaissance report from over the trenches, you can put it into your map. The tool is in QGIS under Raster / Georeferencer. There's a tutorial on how to do this https://www.qgistutorials.com/en/doc...ng_basics.html or web search for "QGIS georeferencing" as the speific button to push may change in future releases.
My top 10 tip here is a trick for all comers - the coordinate system. Like your map that has a reference, your georeferencing will be done against a frame of reference. This is the "EPSG: " number at the bottom of your map frame. EPSG is a quick way to say "I've got the coordinate reference system of my map sorted, here's where the data slots into all the other data layers" and there's thousands of them around the world. Over Britain there's the 1936 National Grid EPSG:27700 - you may like to select that before any mapping over London or the White Cliffs, as it will make your layout look less distorted. When saving the rectified result, let the EPSG of the map frame be the new data too. It will help when you share your file with others, and ensure other scales can be made with it in the future.
There's a tonne of functions in QGIS - like 3D terrain views and having 'live feeds' but that's for another time.
OK, that's probably enough from Moonbeam. I trust you've now got a tool to make playable map bases of wherever you like - be it Hell's Corner, Horsell Common, or Henderson Field.
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