It's pretty interesting. They used lots of ways to deceive the enemy, including inflatable tanks and audio to make it sound like there were many troops and equipment.
During their tenure, they put on a "traveling road show" utilizing inflatable tanks, sound trucks, fake radio transmissions, scripts and pretense. They staged more than 20 battlefield deceptions, often operating very close to the front lines.
It's the insignia of the Ghost Army during WWII.
https://en.wikipedia.org/wiki/Ghost_Army
It's pretty interesting. They used lots of ways to deceive the enemy, including inflatable tanks and audio to make it sound like there were many troops and equipment.