Can satellites help find missing flight MH370?

Mar 13, 2014 by Linlin Ge, The Conversation
Images released by China’s State Administration of Science, Technology and Industry for National Defense that it says are three large floating objects in an area where missing Malaysian Airlines flight MH370 vanished. Credit: AAP/SASTIND

China has released several satellite images its officials say could be wreckage from the missing Malaysia Airlines flight MH370 with 239 people onboard.

If they are proved to be true it shows how satellites can play an important role in locating the wreckage of a crashed plane. It can be done within a couple of hours after the accident if multiple high-resolution satellites are used.

About satellites

Remote sensing satellites can be broadly classified into two categories – optical and satellites.

Optical satellites can now deliver unclassified images at a resolution of half a metre while radar satellites can provide unclassified images at one metre resolution.

Metallic structures such as plane wreckage can produce strong return on radar images, making them easily visible. Satellite imaging radar can also "see" through any cloud and can take images day and night.

According to China's satellite images – taken over the suspected crash area a day after flight MH370 went missing on Saturday – the largest object shown is about 24m by 22m. This is clearly large enough to be imaged by both optical and radar satellites.

It should be noted from the images that the object is closely surrounded by cloud. Any potential wreckage would not be spotted by optical satellite if it were covered by cloud but it would still be visible on a radar image.

That's why it makes sense to use both optical and radar satellites in any search for the location of plane wreckage.

The search much slower at sea level. Indonesian Search And Rescue (SAR) members looking for the missing flight MH370 in the Malacca straits, near Aceh Sea. Credit: EPA/ Hotli Simanjuntak

Eye in the sky

Satellite remote sensing has many advantages over conventional air and sea search using ships and aircraft.

The satellites orbit around Earth at a height between 200km to 900km and can cover a large area, typically 100km by 100km (100,000 square kilometres – about the size of Cuba) or even 500km by 500km (250,000 square kilometres – about the size of the UK), with a single image collected in only a few seconds.

It would take an aircraft between 1.5 and 34 hours to cover the same area. A ship will take much longer.

So it is much more cost effective to use remote sensing satellites to search over large areas.

Another advantage of satellites is that once in orbit the cameras and radar sensors on board are always on standby. They can be switched on immediately, as soon as the space agencies are informed of an accident, and be pointed straight at the area around the last known coordinates of the aircraft.

This also makes them much quicker to respond to incidents such as the air crash than the air and sea search vessels.

Another advantage is that satellites can take images globally without the issue around border protection so it is much easier to use them in international search.

Any limits?

Although the remote sensing satellites have the potential for global coverage some do have difficulty in imaging the two poles. That's because they use near-polar orbits and not all of them have side-looking capability – they mostly look only down.

Satellite radar monitoring of NSW floods near Grafton in 2011. Processed by the Geodesy and Earth Observing Systems Group, UNSW School of Surveying and Spatial Information Systems. Credit: ASI

If an aircraft goes missing in the mountains, there is also a good chance that any wreckage may be hidden under the forest canopy. Although long wavelength radars can penetrate tree canopy, they may still have difficulty in seeing through the dense tropical forest.

In contrast, the open sea is a more favourable environment for searching a missing aircraft with satellite remote sensing, because the main features in a will be just sea water and the plane wreckage – there is less chance of confusing any wreckage with any other targets, such as trucks, trains or farm houses, as in the case of a plane crash on land.

Satellites in other disasters

Since 2008 the Geodesy and Earth Observing Systems group (GEOS), at the UNSW School of Civil & Environmental Engineering has responded, in near real-time, to a range of natural disasters using both optical and radar .

These events include major earthquakes in China and New Zealand, bushfire in Victoria and floods in Queensland, New South Wales and Victoria.

The team has repeatedly demonstrated that intelligence such as ground deformation, fire and flood extent can be extracted and delivered to relevant authorities within two hours of satellite image capture.

Explore further: Satellite guardians join search for missing plane

add to favorites email to friend print save as pdf

Related Stories

Crowdsourcing search for missing plane is overloaded

Mar 11, 2014

A crowdsourcing effort to locate the missing Malaysia Airlines plane using satellite imagery overloaded the computer network with an "unprecedented" amount of traffic, the technology company said Tuesday.

US suspects missing plane flew on for hours

Mar 13, 2014

US investigators suspect a missing Malaysian airliner was in the air for four hours after its last confirmed contact, and may have been diverted to an unknown location, the Wall Street Journal reported Thursday.

Japan launches two intelligence satellites

Jan 27, 2013

Japan launched two intelligence satellites into orbit on Sunday amid growing concerns that North Korea is planning to test more rockets of its own and possibly conduct a nuclear test.

Japan launches new spy satellite

Dec 12, 2011

Japan launched a new spy satellite into orbit on Monday amid concerns over North Korea's missile programme and to monitor natural disasters in the region, officials said.

Recommended for you

Report: FBI's anthrax investigation was flawed

Dec 19, 2014

The FBI used flawed scientific methods to investigate the 2001 anthrax attacks that killed five people and sickened 17 others, federal auditors said Friday in a report sure to fuel skepticism over the FBI's ...

Study reveals mature motorists worse at texting and driving

Dec 18, 2014

A Wayne State University interdisciplinary research team in the Eugene Applebaum College of Pharmacy and Health Sciences has made a surprising discovery: older, more mature motorists—who typically are better drivers in ...

Napster co-founder to invest in allergy research

Dec 17, 2014

(AP)—Napster co-founder Sean Parker missed most of his final year in high school and has ended up in the emergency room countless times because of his deadly allergy to nuts, shellfish and other foods.

LA mayor plans 7,000 police body cameras in 2015

Dec 16, 2014

Mayor Eric Garcetti announced a plan Tuesday to equip 7,000 Los Angeles police officers with on-body cameras by next summer, making LA's police department the nation's largest law enforcement agency to move ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.