For the July, 2009 Street-O at Palo Verde Park, we used a combination aerial photo/orienteering map, or what I call a “hybrid” map. The basis for the map is a detailed photo of the neighborhood, with a few things added to make it ready for orienteering. In this case, I added streets and utility easements/alleyways, as well as a few special features like footbridges, fences, washes, and out-of-bounds areas. Essentially, the mapped elements indicated where you were allowed to run, and the photo gave you all the extra information you needed to find your controls. You can see the map below.

Why make a map like this? For one thing, adding just the streets and alleys to the photo was a lot less time consuming than making an entire O map of the neighborhood. I was able to do most of the drafting without even visiting the area. A map like this is also a lot easier to read than a plain photo, enhancing the experience for the runners. It takes away some of the ambiguity of where it is okay to run, and also doesn’t require eagle eyes just to figure out where the streets are. Essentially, there is a really great enjoyment-to-work ratio!

So, how do you make one of these maps of your own neighborhood? It’s easy, and a great way to get started with using OCAD and getting into mapping. Plus, you’ll have help—just ask! Here are some basic directions to get you started.

What you’ll need:

1. A computer with some version of OCAD, the orienteering cartography program. The full version of OCAD 6 is available for free on www.ocad.com. Ludwig Hill has copies of the easy-to-install demo version of OCAD 8 (a much improved version over OCAD 6) that he can make available to you.

2. A basic image editing program.

3. A few afternoons to sit down and work.

The first step is to get your aerial photo. In Arizona, we’re lucky to have the Arizona Regional Image Archive, where it is possible to download high resolution imagery for the whole state. What you’ll want is to find the DOQQ (Digital Orthophoto Quarter- Quadrangle) that covers your section of town. The Color DOQQs from 2005 work just fine. This will be a really big file (close to 150mb) covering a large area, but it will also be geo-referenced, which means that programs like OCAD will know the scale of the map and the actual, real-world coordinates associated with locations on the imagery. This makes creating the map very easy.

Note:  You can now download even better quality aerial photos from the USGS National Seamless Server.  For an explanation on how to do this, download the "How to Make a Street-O Map" guide from the Reference Guides and Forms page.  

The next step is to use your photo editing program to crop the DOQQ down to something more usable. Save both files; you’ll need them next. Open up the DOQQ in OCAD as a template (set your scale to something you’ll want to use, like 1:10000), then open up your cropped image as another template and adjust the cropped image to match the DOQQ. Close the DOQQ and forget about it; you now have a small area that is perfectly scaled the
way you want it.

Now you’re ready to start adding map elements! If you’ve never used OCAD, then you’ll need to take some time reading the help files and just experimenting with the different tools. Once you are comfortable selecting different features and editing them, you will be able to add streets and alleys by drawing them right on top of the image. Some things you won’t be able to make out exactly, but it will only take a little bit of field work to figure it out. If you’re new to using OCAD, then it will probably take a little bit of practice to draw curves with the bezier tool, but it’s worth it! Start with straight lines and rectangles and add the curvy parts as you get better. Don’t worry about tiny details like extra-wide streets or parking lots; you’re making a very generalized map!

Once you have all of your mapped elements in place, dim the template to about 40%. This makes the mapped elements stand out but still allows you to be able to read the details from the imagery. You can use OCAD to set courses, or you can just print your map as-is and draw on it. And then you’re ready to host your own Street-O!

Image of a Street-O Map