Heres some stuff i found about heat scans and such
"Infrared imagers detect nothing more than the heat emitted by all the objects in the cameras field of view. They do not see visible light. They cannot see through buildings. In most cases, they cant even see through glass. They are not radar. They do not emit rays or beams of energy. Thermal imaging systems are completely passive and non-intrusive. In simplest terms, thermal imagers operate like the human eye. Energy from the environment comes through a lens and is registered on a detector. In the case of the thermal imager, that energy is heat. Advanced electronics convert the heat into a visual image on the viewfinder or a monitor...
Many agencies throughout the United States use thermal imagers, or infrared systems, to conduct thermal profiles of buildings suspected of harboring illegal cannabis growing operations. An airborne forward-looking infrared unit or a handheld thermal imaging camera can be used to conduct these thermal audits. Such audits are usually used to corroborate other documented evidence that is already be on hand...
The thermographer is not looking for an exact temperature. He's looking for heat anomalies, or elevated temperatures characteristic of a grow house. If the building is warmer than similar nearby structures, it will look brighter in the viewfinder. Indoor marijuana-growing operations generate a lot of heat, most of it from the high-wattage bulbs that simulate sunlight. That heat is transferred to the walls and roof of the building...
Test cases have shown that IR imaging systems can be used without violating Fourth Amendment protections under the following conditions:
The area being observed is an open field, curtilage or backyard of a house, or is a commercial structure where the investigator has a right to be.
The point of observation is public property, navigable airspace or private property used with the owner's permission.
Using thermal imaging systems to monitor dwellings may involve a different set of legal issues. Infrared imagers detect nothing more than the heat emitted by all the objects in the cameras field of view. They do not see visible light. They cannot see through buildings. In most cases, they cant even see through glass. They are not radar. They do not emit rays or beams of energy. Thermal imaging systems are completely passive and non-intrusive. In simplest terms, thermal imagers operate like the human eye. Energy from the environment comes through a lens and is registered on a detector. In the case of the thermal imager, that energy is heat. Advanced electronics convert the heat into a visual image on the viewfinder or a monitor...
Many agencies throughout the United States use thermal imagers, or infrared systems, to conduct thermal profiles of buildings suspected of harboring illegal cannabis growing operations. An airborne forward-looking infrared unit or a handheld thermal imaging camera can be used to conduct these thermal audits. Such audits are usually used to corroborate other documented evidence that is already be on hand...
The thermographer is not looking for an exact temperature. He's looking for heat anomalies, or elevated temperatures characteristic of a grow house. If the building is warmer than similar nearby structures, it will look brighter in the viewfinder. Indoor marijuana-growing operations generate a lot of heat, most of it from the high-wattage bulbs that simulate sunlight. That heat is transferred to the walls and roof of the building...
Test cases have shown that IR imaging systems can be used without violating Fourth Amendment protections under the following conditions:
The area being observed is an open field, curtilage or backyard of a house, or is a commercial structure where the investigator has a right to be.
The point of observation is public property, navigable airspace or private property used with the owner's permission.
Using thermal imaging systems to monitor dwellings may involve a different set of legal issues. "