By Peter Bowes
BBC News, Los Angeles
Unmanned aerial vehicles (UAVs), commonly known as drone aircraft, are about to be launched for the first time by the police in Los Angeles.
The drone is quickly assembled and easily launched
UAVs have long been used by the military in war zones such as Iraq or Afghanistan. But the technology has been adapted for domestic use and could revolutionise the way law enforcement agencies carry out surveillance and rescue operations.
The Los Angeles Sheriff's Department (LASD) has been experimenting with a drone called SkySeer, which it intends to put into service later this month.
SkySeer looks like a remotely controlled model aircraft. It has a wingspan of 6.5 feet (1.98m) and weighs 4 pounds (1.81kg). A camera is attached to its belly and a small battery powers the drone.
"It has a video link that sends data in real time down to our ground station - the operator can then see, in real time, what it's seeing," explains SkySeer inventor Sam De La Torre, from Octatron Inc - a surveillance technology firm.
The SkySeer has been designed for quick and easy use by police officers on the street. It can be folded up and stored like a tent in a backpack.
"Within five minutes he can have the aircraft assembled,' says Mr De La Torre
SkySeer can fly at speeds of 30mph (48 kph)
"You just push the take-off button, the motor starts up and you throw it."
The UAV can fly at any height. At 250 feet above the ground, it can clear a 25-storey building and is almost invisible.
The Sheriff's Department is keen to start using the drone in situations where conventional crime-fighting is either impractical or too expensive.
At a cost of approximately $25,000 - $30,000 (£13,400 - £16,000), the UAV is considerably cheaper than a helicopter. But the device's practical applications are generating the most excitement amongst officers.
"It provides several things that we can't get other ways," says Commander Charles Heal, head of the LASD's technology exploration project.
The UAV's ability to hover in virtual silence over an accident or crime scene, without any risk to a pilot, provides both a tactical and economic advantage.
It is envisaged that SkySeer will be put to use when children go missing down a hillside in difficult terrain.
To save time and minimise the risk to rescuers, the UAV will be used overhead to pinpoint the location of a victim.
"It has different cameras - colour, low light and even infra-red - and so as a result of that we can even find heat signatures that are coming through the bushes and overhead," says Commander Heal.
With burglaries, the police say the SkySeer will be used get an aerial view of a building where someone is believed to have broken in through the roof.
The conventional approach is to call the fire department to bring in ladder trucks, allowing officers physically to climb onto the top of a building.
"If the suspect really wants to hurt you, your head is the first thing that he sees. Now we'll have the ability to actually to fly this over and see if it is even worth doing a containment."
The UAV utilises an onboard compass and GPS system for its command and control. It flies to a location that is predetermined by the operator on a laptop.
The developers are working on a so-called cyber command post to enable images to be viewed, anywhere in the word, in real time.
"If we're flying over hazardous material or something that we can't recognise, we can have a subject matter expert, maybe not even in the country, in a different time zone, that is actually watching the exact same information that we're getting.
'Big brother' surveillance?
"We will be able to incorporate his subject matter expertise into our decision making process," says Commander Heal.
The SkySeer will also be used to back up officers on the ground if they are pursuing a suspect on foot. Flying at a speed of about 30 mph (48 kph), the police believe it will be impossible for a suspect to outmanoeuvre the UAV.
"You simply point the camera at him and keep following."
The drone can be folded away
The Los Angeles Sheriff's Department has only one prototype SkySeer at the moment.
When it goes into service, the force's SWAT [Special Weapons and Tactics] unit will carry out the initial evaluation in real-life situations.
Commander Heal is quick to point out that it is not their intention to launch 'big brother' style surveillance operations.
"There's no place in an urban environment that you can go to right now that you're not being looked at with a video camera and you have nothing to fear from your own government - you are being watched by your fellow citizens," he says.
"The only time that this is ever going to be operational is in some kind of emergency condition."