Keeping Dogs Off My Lawn

I don't own a dog. Not that I wouldn't like to, but the idea of picking up dog feces does not interest me. Yet, all over my lawn, there's dog crap. I can almost guarantee that most of it, if not all of it, comes from my neighbor's dog that roams free.

My neighbor's lawn is pristine. Of course the dog doesn't want to release bowels there. It would rather use my lawn, then it can lie around in its own lawn without worrying about rolling in its own crap.

The grown up thing to do would be to politely ask my neighbor to keep his mutt in his own yard, or to at least ask him to pick up the piles of crap that is in my lawn. But, I think my neighbor has denial issues (he's seen crap in my yard and blamed it on other dogs), and I avoid confrontation at all costs, so I simply let the crap accumulate.

I've tried spreading some smelly stuff that dogs don't like around the border of my lawn. Do you think that helps? Nope. The dog just walks right through the invisible fence of odor without smelling around first.

Then I think, how can I automate keeping dogs off of my lawn without absolutely annoying my neighborhood, avoid lawsuits from people simply using the sidewalk, and without killing the dog.

My original idea was to have a water cannon of sorts that would somehow target the intruder and spray it with water. That sounds too complicated, and I can just see the mailman complaining when he gets soaked while crossing my lawn to deliver the mail.

Thinking more about it today, perhaps some pneumatic solution would suffice. Dog enters the lawn, then a loud rush of compressed air is released to scare it away. Or maybe it powers a ultrasonic whistle or something that, again, is intended to scare the dog out of my yard.

I would need a sensor system to detect the intrusion. Infrared lasers could be used, perhaps in the same way that swimming pool alarms use them (the goal would be the same as swimming pool intrusion alert systems, so I could borrow from that pool of technology, pun intended).

Once triggered, a solonoid would release the compressed air, which would then power the [insert dog scaring aparatus here]. After a set time, the solonoid would turn off, and the system would be armed again.

Pneumatics don't work that well outdoors in the winter time where I live, so this might just be a seasonal approach. But, I guess the goal is to train the dog to stay out of my yard, so using the system from spring to fall just might suffice.