The truth is that it's spelled Helicopter! Nah I'm just kidding....
What would be putting off heat in an outdoor grow? I guess if you don't want them to find your plants heat signature, burn fires around your crop to evade detection!
Visual identification is their only method of detection for the eradication forces here.
There is no behavior that a grower can engage in to prevent detection from the air. The coloring of cannabis, all cannabis, is so distinct that it stands out in the enviroment and their isnt a single thing you can do to prevent the plants from being seen if the choppers are over or near your grow.
Some things that help?
Grow green varities. Purple plants or plants with wide dark green leaves are even more obvious from the air. Smaller, and especially single cola dominant varieties are more difficult to spot than a huge bush.
Helicopter threads in the outdoor forum are like Global warming and yummy threads in the den, LOL!
Helicopters find your plants with the naked eye. In dry country this makes it easier, because the surrounding foliage isn't receiving water like the Cannabis, so the plants will appear a more vibrant green, even in country that stays green a experienced spotter can pick out the MJ.
The best strategies to hide Guerrilla plants from choppers in descending order of importance:
#1. Don't plant in open places: Don't plant in the middle of the meadow, plant at the edge of it, near the shrubs/trees. Always try to find places busy with other natural plants to hide yours.
#2. Plant your crops spread apart: In the old days, choppers could spot plants often because growers would not only plant close together, but often in organized rows to help make irrigation easier, to a aircraft these rows look unnatural even before you can see what species the plants are. Ideally plants should be at least 20' apart, if not much further.
#3. Don't beat paths through grass to your plants, or leave junk or equipment of any kind visible, don't give the chopper something to look at and hang around, it may lead them to your patch.
#4. Keep your plants a reasonable size: Don't try to grow huge pound plus plants, 4 1/4lb plants spread appart will be more hidden than one pound plant.
The sheriffs of all the local counties here bust many people every year, using helicopters. They can afford the fuel because the federal government pays them to do it. But no thermal imaging is being used, its just a guy with his head hanging out the side, looking for big grows.Usually they bust one or two grows by chance with the flying pig chopper thermal imaging on the way back from a call out,, then they over-HYPE the result in the media!!!
We only know x1 person that got caught by a police chopper,, they had x1000 + plants,, and they went to jail for cultivation,, however they lived next to the chopper pad! lol
Ordinarily it would be a complete waste of aviation-fuel to aimlessly fly about all day looking for ganja plants.
Hope this helps