Advice from dog lovers needed

Get a sign saying "Please do not empty your dog on my property"

That is disgusting. Responsible dog owners pick up after their dog. Hot cayenne pepper might deter the dog but it’s the owners who need to be deterred. You could try a note saying “Please pick up after your dog”. You could also see if your local council has a dog warden. In our village we have official signs from the council warning of fines up to £1,000.

Same problem we live over the road from entrance to woods. We have a dog ourselves we go out with bags scoop etc but others obviously don’t. We put a sign up on our fence ‘Take it home’ it’s made a bit of a difference but not a great deal. I complained to the local council it took months for them to respond last year. When they did they put signs up know where near our house!

Definitely put up a sign of some kind. (I love Bathsheba's suggestion.)

Dogs hate the smell of vinegar, and its application in a few strategic locations may do the job. Although I don't think the smell would last long outdoors?
The option of cayenne pepper can cause serious irritation to a dog’s nose, and as someone rightly said, it's the owners fault not the dog!

You could get a CCTV sign? I tend to think that if the owner is ignorant enough to allow their dog to do this, a sign may just be ignored too.
I think I'd be tempted to get up early and confront the person!

Do you have an open driveway? My dog (embarrassingly) always wants to go in the middle of the same drive which leads to two houses, because dogs like to go in an open space, it’s an instinct to enable them to see any danger from a distance. I always drag him to the kerb obviously, but I think if that is the issue, your best bet is to break up the open space - planters, a gate, or whatever.

Put a gate across the drive or get up early to catch the culprits.
Then shovel up the poo and chuck it into the road in their direction, accidently, at the same they are walking back or leave it on their car bonnet if they drove there!!

Recording equipment. Amazon. About 100 pounds. Owners dont want to be filmed allowing their dog to do it

Dogs are drawn to the smell of previously soiled spots, as are cats. Enzyme spray breaks down the odour. Biological washing liquid might do the trick.
I deter cats with Vick rub mixed with coffee grounds, seems to do the trick.

You can buy various chemicals that are said to work.

Putting up a sign will probably not do the slightest bit of good. The owners don't care, so a sign won't help.

My solution is a cat who dislikes strange dogs and has terrorised all our doggy neighbours into good behaviour just by sending them dirty looks.

I did once hear him growl, but I think the dog in question was thinking of chasing the cat.

Strange as I was reading this my dh came in to say he found 3 bags of dog poop in our dust bin which is tucked away on the drive at the front of the house...