Scanned Maps

Thanks to Hank Riley, I've incorporated the ability for you to scan in maps (or capture images of them from the web or wherever) and use them for plotting the predicted track of your balloons.

Further thanks go to Dan Stephens for links to two programs/web services that will enable you to download some excellent maps from the net. See the Scanned Map Image Sources page.

The accuracy of the plot is dependent on the map being of the correct type of projection. The only type of map that will accurately plot is one with a mercator projection. That is, the distance in DEGREES (on the map) is equal in magnitude for both latitude and longitude regardless of the latitude of the map.

As you're probably aware, the closer to the poles of the planet the closer in distance the lines of longitude are. Some mapping programs ignore this and display longitude lines as perpendicular to latitude lines. What this means is that a degree of longitude is essentially equal to a degree of latitude when mapped on a computer screen in pixels. This makes mapping very easy, but the results look very strange close to the poles (mercator projection of say Greenland).

If you have some type of conic projection map, you might be able to manipulate it in something like Photoshop to stretch the map so it's in "mercator" projection. I did this in a couple of the examples below.

Step one is to obtain a "map". I put map in quotes because you can plot on anything that you can definitely identify two position points' latitude and longitude coordinates. In the examples below you'll see what I mean.

Next start Balloon Track and click "Scan Map". When that screen opens, select [File/Open Map] from the menu and load the map of your choice. It must be in one of three formats to be properly displayed - GIF, JPG or BMP.

Register the Map

When you first use a map, Balloon Track needs some information in order to determine the geographic coordinates of the map so that it may plot data on it.

While the map is displayed on your screen go to the menu and choose [File/Map Registration/Two Point Registration].

Next, move your cursor to a location on the "map" you can definitely and accurately point to and identify. Right click the mouse, and select "Point 1". A dialog box opens, you enter the latitude and longitude for that point.

Next pick another point and repeat the above procedure using "Point 2".

A hint here, opposite corners of the map (NW to SE or perhaps SW to NE)  are the most ideal locations to select the two point from as any slight pointing error should be somewhat smoothed out by the distance from one point to the other.

That's it! The map currently displayed on the screen is "saved" as the default map, and the coordinates represented by the map are also saved (in a file with the same full name of the map file with the addition of .dat on the end ... colorado.gif would have an accompanying colorado.gif.dat file it you had registered the map as described above). From then on, whenever you open that map, the coordinate system will be read in from the dat file, so you only have to register the map when you first use it.

Resizing

You will note on the Menu there is a [Form to Map Size] option. If you stretch the map it will get bigger but it will also get quite pixelated. Click this option and the map will resize to it's native resolution.

Here are some examples:

Since so many of you use Street Atlas here's an idea. I opened Street Atlas, sized the screen to cover the area of a typical flight and did a screen capture, then brought that capture into BT, registered it from data I took off the still open screen in SA and I was immediately in business.

I've added some new features to the scanned map screen that do not appear in the screen shots below but are evident above.

There is a new menu item, "Multiple Tracks". Click on this and a sub menu drops down offering True, False and Save to INI. Set to True you can run multiple predictions and they will "stack up" on this map. However, NOTE, if you close, maximize, minimize or resize the map, only the most recent prediction currently in memory will display.

The screen now has a status bar which shows the name of the map currently loaded (lower left) and the bearing and range from launch to touchdown (lower right). Also, the launch and touchdown locations on the map are annotated. It's hard to see the launch location annotation above but the touchdown is clearly indicated. The track now shows three "dots". The green circle bounded by a red border is the launch site. The solid red circle is the burst point. The red circle with the green border is the touchdown location.

If the screen captures below were captured with the current version of the program, all these features would appear on each screen shot.

The tracking and recovery team in Colorado uses this map. If you compare this flight track with the map immediately  below you'll note that the balloon starts out to the WEST of the interstate here and slightly east of it in the other map. This map is badly registered. The problem with this map is that I didn't get a good flat shot of it and it became somewhat distorted. But, I post this bad map as a reminder to get the best scan you possibly can. Also, no compensation is made for different cartographic projections. Only a mercator projection where each degree of latitude and longitude are represented at the same scale will plot correctly. So, this scanned map thing will never be as accurate as using the MapPoint option or the export of a track to Street Atlas.

The Map above is really to large to be useful, so I grabbed a close in shot of the north eastern quadrant of Colorado and got this map:

I took a snapshot of this area of the map with my digital camera, did some work in Photoshop to reduce the size of the picture, then brought it into Balloon Track and registered two points (one in the lower part of the Denver metro area, specifically the intersection of C-470 and I-25, the other up in Sterling which is about 1/3rd of the width of the map from the eastern border and about a quarter of the height of the map from the top, specifically in that case the intersection of I-76 and US 6. I ran a prediction in BT and the line above appeared.

I'm no artist, so I just took the Colorado Scanned map above and traced over it. The idea, you could draw out a map on paper or sketch one in the computer and use it. If you have any cartographers in your group, maybe they'd like to make a custom map of your area, who knows. I'm just having fun with a new option.

More examples:

I scanned this map from a little pocket map book I keep in the car.

This is a terrain wall map.

This is a Satellite picture from GOES x ... whichever GOES is currently on duty over the Pacific. One note here, that satellite picture is looking at Colorado from a position quite far to the South West of the state. So, every latitude and longitude line was skewed. I had to take the picture into Photoshop and "straighten" it out so I could use it for plotting purposes.

And of course, just to show off, here's a postcard of the State with the track drawn on it.

Recommendations:

Register your map with points as widely separated in BOTH latitude and longitude as possible.

You might want to scan in a map at very high resolution and keep it as a master. Then, when you know the general direction of your flight, use an image editor to select and save a smaller subsection of that map for actual plotting.

In most cases above I stretched the maps of Colorado so that the projection was altered. This resizes the map so that the longitude lines are the same distance apart regardless of latitude. This helps in getting a fairly decent plot as the program assumes that the distance between longitudinal lines is equal. I used Photoshop, but any decent editor should do. The smaller the territory the map covers the more accurate the plots will be.

Image Editors:

Photoshop - It's the industry standard and if you can justify it's expense a terrific editor ... but it is $600

Photoshop Elements - Is Photoshop too much of a shock to your budget (certainly understandable) take a look at its ligher weight cousin. It is a subset of the full program, but I think you will find just about every thing you need in it if you are just retouching graphic images and it's 1/6th the cost ($100). Photoshop adds lots of features that most folks can live without.

See the Adobe Web Page that a compares Photoshop and Photoshop Elements to see why one costs $100 and the other $600.

GIMP - The GNU Image Manipulation Program is a very powerful image editor on a par with Photoshop. It's available on Mac OS-X, Linux and Windows too so no problem getting it onto your machine. If you are a Mac user there is also a "Skin" called Gimpshop that remaps the user interface to very closely resemble Photoshop. And, if you are a windows user, Gimpshop's "source code" is publically available so a few folks have also posted Windows versions to skin that incarnation of Gimpshop.

So, if you use Photoshop at work but don't have a copy at home this might be of interest.

GIMP Program Page - primary download is the program itself, follow links to your OS version

Gimpshop for Mac - a plugin to Photoshopify GIMP on the Mac

Gimpshop on Windows - I'm linking to a site that supports a particular version of Gimpshop for Windows but you might want to to a Google Search for Gimp on Windows to see if anything new shows up. It's open source so I've noticed there are a few different flavors of this plugin.