I’ve not been through the whole patent in detail (the bits I read made me so angry I had to stop myself from reading the rest), but the small amount I’ve read, I would consider to be a little misleading, here are some examples

“While radar is an excellent means to detect metal objects, it is less sensitive in detecting non-metallic objects, such as rubber. Objects made of materials having poor radar signature (e.g. rubber) can cause major problems for such radar-based systems. Further, radar may not be relied upon for detecting smaller non-metallic objects.”

Yes, radar is less-sensitive to non-metallic objects, but I’ve been on a runway and seen a radar system detect a very small clump of grass.

“Further limitations include radar blind spots or shadows due to blockages caused by other objects or infrastructure.”

It’s true, radars cannot see through solid objects (another way to say that is that radars “detect solid objects”!),  visible (or thermal) cameras can also not see behind “objects or infrastructure”. I’m intrigued to see what technology they are using that enables them to see through solid objects!

“In addition, radar may trigger a false alarm by indicating a strong signal for signals reflected from even small metal objects that may not be so hazardous”

Say what now? is this actually trying to say that the ability to detect small metal objects is a bad thing? I’d like to know exactly which metal objects that are about to be sucked into my jet engine I should not be concerned with!

Anyway, that’s enough about radar, let’s move into the infra-red (the shorter wavelengths are far more interesting anyway).

“Some airports utilize infrared or thermal-imaging systems to detect objects, cracks voids etc. on a runway. However, systems employing infrared or thermal-imaging systems can only sense the infrared radiation (emitted from objects)….”

Really?, so there’s no infra-red energy reflected from objects by that tiny IR emitter in the sky we call the Sun? it’s all emitted?

“…..which is outside the thermal equilibrium of the surroundings i.e. a infrared or a thermal imaging system can only detect objects (e.g. a piece of warm metal debris on a cool runway) which have sufficient thermal contrast. Small objects which have poor thermal contrast may pose significant challenges for infrared / thermal imaging system”

again, reflected IR radiation from the Sun excludes some of these issues, but the emissivity of the objects is also a major factor, two objects of the same temperature can have a high IR contrast due to their different emissivities.

And let’s not forget, visible cameras also require contrast, it’s hard to see a loose piece of concrete on a runway which is made of concrete, they tend to be the same colour (and the same temperature, and have the same emissivity!)…….it would be no problem for a radar though

Singapore, 19 May 2011 – Singapore Exchange Mainboard-listed Stratech Systems Limited (“Stratech” or “the Group”) today announced that its Singapore patent application for the iFerret™ Intelligent Airfield/Runway Surveillance and FOD (Foreign Object and Debris) Detection System has been approved by the Intellectual Property Office of Singapore (“IPOS). Beyond Singapore, Stratech is seeking to protect its IP in iFerret™ with similar patent applications filed in countries worldwide.

Designed and developed in Singapore, Stratech’s iFerret™ is the world’s first Intelligent Vision-based FOD Detection System. Using Stratech’s Intelligent Vision software and state-of-the-art Electro-Optic (EO) Sensors, iFerret™ automatically detects, locates, classifies and records FOD in commercial airports and military airbases. Upon the detection of FOD, iFerret™ enables operators to zoom in on the subject for visual verification before sending a remote alert to ground crew to remove the FOD.

The cutting-edge iFerret™ is the approved Electro-Optical Detection System in the Advisory Circular (AC) No: 150/5220-24 on Airport Foreign Object Debris (FOD) Detection Equipment issued by the U.S. Federal Aviation Administration (FAA) in September 2009, which has been adopted by airports around the world as the de-facto standard for FOD detection. Following this AC, US airports will be able to apply for government funding to procure FAA-approved FOD detection systems such as iFerret™. The two government funding schemes available to US airports are the Airport Improvement Program (AIP) and the Passenger Facility Charge (PFC) Program.

The value proposition of iFerret™ goes beyond the runway. A FOD study by the UK’s Civil Aviation Authority revealed that although 50% of FOD damage occurred on the runways, the majority of FOD detected are located beyond the runways with the taxiways and other Air Operations Areas such as the apron accounting for 85% of FOD detected. With the world’s first taxiway installation at the Chicago O’Hare International Airport (USA) and the world’s inaugural apron deployment at Düsseldorf International Airport (Germany), iFerret™ is the only system in the market that can enable airports monitor not just runways, but also taxiways, aprons and other Air Operations Areas.

Runway visibility at night is paramount to airport operational safety. Despite the presence of airfield lighting, night operation remains a challenge to airports due to poor runway visibility under low light conditions. iFerret™ brings a breakthrough in alleviating this issue with its impressive night vision capability, which enables airport operators survey the runway. Furthermore, iFerret™ has also been proven to perform under extreme weather conditions, such as haze and heavy rainfall.

Another value proposition of iFerret™ is to provide airfield pavement condition monitoring. Aviation regulatory bodies advocate regular monitoring of pavement surfaces. For example, the FAA requires airports to conduct annual pavement inspections for certification purposes. iFerret™ enables real-time and automatic pavement condition monitoring. It has been proven to detect abnormal pavement conditions such as pavement cracks, tarmac potholes, pavement deterioration and snow accumulation.

“iFerret™ is the future of Airfield Safety and Surveillance,” says Dr. David K.M. Chew, Executive Chairman of Stratech. “The market potential of iFerret™ is tremendous. Not only will it bring significant contributions to commercial airports around the world, airbases will also benefit from the military version of iFerret™, which performs airfield Battle Damage Assessment.”

Source (Stratech Press Release page, download as PDF)