First of all, I do not have access to professional audio recording equipment. Nor do I have something that is designed for mobile recording. I have a laptop and a decent microphone. Before I actually attempted to do this, I thought that would be enough. In my mind, I thought, "Oh, I'll just bring the microphone onto the track to record footsteps. No big deal."
Hey, you know what's creepy for a grown man to do? Bring ANY kind of recording device to a grade school. (I just want to mention that I went on a weekend - there were no children or teachers.) You know the moment that I realized this? When a woman pulled into the parking lot to go and exercise on the track right after I got there. So, I spent the first forty minutes of my time there just waiting in my car, wondering if I should just go back home. Finally, she left and I was able to feel less self conscious. I bet there's security camera footage that now exists of me just holding a microphone up to the wind.
I couldn't bring my "setup" to the track because it was - you guessed it - raining. The one day I had to go there, it was raining. It was raining and there were violent winds. Each aggressive gust created nasty clipping sections in the tracks I was using to capture atmospheric samples. At least I could run in place next to my car and get half way decent footsteps. The raw footage required some serious remastering to become acceptable to throw into my game.