How do laser altimeters work?

A laser altimeter works by emitting short flashes of laser light, which travels to the surface of the planet, where they are reflected. Part of the reflected laser radiation returns to the laser altimeter, is detected, and stops a time counter which was started when the pulse was sent out.

How is flight altitude measured?

Aviation altitude is measured using either mean sea level (MSL) or local ground level (above ground level, or AGL) as the reference datum. Absolute altitude is the vertical distance of the aircraft above the terrain over which it is flying. It can be measured using a radar altimeter (or “absolute altimeter”).

Can GPS give altitude?

Global Positioning System (GPS) receivers can also determine altitude by trilateration with four or more satellites. In aircraft, altitude determined using autonomous GPS is not reliable enough to supersede the pressure altimeter without using some method of augmentation.

What is the use of barometer?

A barometer is a scientific instrument used to measure atmospheric pressure, also called barometric pressure. The atmosphere is the layers of air wrapped around the Earth. That air has a weight and presses against everything it touches as gravity pulls it to Earth. Barometers measure this pressure.

How do altimeters measure altitude?

An altimeter is a device that measures altitude—a location’s distance above sea level. Most altimeters are barometric, meaning they measure altitude by calculating the location’s air pressure. They determine altitude by measuring air pressure. As altitude increases, air pressure decreases.

How do the altimeters work and what is a flight level?

The altimeter measures the height of an aircraft above a fixed level. The instrument senses this by taking the ambient air pressure from the static port. As the aircraft goes up, the pressure inside the case decreases and the bellows expand. The opposite happens as the aircraft descends.