US and China racing to deploy quantum ghost imaging in satellites for stealth plane tracking

China is developing a new type of spy satellite using ghost imaging technology which could spot stealth aircraft and see through smokescreens and camouflage.

Above – A 2009 US Air Force Research lab presenter on quantum ghost imaging satellites.

Quantum ghost imaging can achieve unprecedented sensitivity by detecting not just the extremely small amount of light straying off a dim target, but also its interactions with other light in the surrounding environment to obtain more information than traditional methods.

The ghost imaging satellite would have two cameras, one aiming at the targeted area of interest with a bucket-like, single pixel sensor while the other camera measured variations in a wider field of light across the environment. By analyzing and merging the signals received by the two cameras with a set of sophisticated algorithms in quantum physics, scientists could conjure up the imaging of an object with extremely high definition previously thought impossible using conventional methods. The ghost camera could also identify the physical nature or even chemical composition of a target, according to Gong. This meant the military would be able to distinguish decoys such as fake fighter jets on display in an airfield or missile launchers hidden under a camouflage canopy.

Tang Lingli, a researcher with the Academy of Opto-Electronics, Chinese Academy of Sciences in Beijing, said numerous new devices had been built, tested in the field and were ready for deployment on ground-based radar stations, planes and airships.

Gong Wenlin, research director at the Key Laboratory for Quantum Optics, Chinese Academy of Sciences in Shanghai – whose team is building the prototype ghost imaging device for satellite missions – said their technology was designed to catch “invisibles” like the B-2s.

He said his lab, led by prominent quantum optics physicist Han Shensheng, would complete a prototype by 2020 with an aim to test the technology in space before 2025. By 2030 he said there would be some large-scale applications.

While ghost imaging has already been tested on ground-based systems, Gong’s lab is in a race with overseas competitors, including the US Army Research Laboratory, to launch the world’s first ghost imaging satellite.

The chinese team showed the engineering feasibility of the technology with a ground experiment in 2011. Three years later the US army lab announced similar results.

Recently, it was shown that the principles of ‘Compressed-Sensing’ can be directly utilized to reduce the number of measurements required for image reconstruction in ghost imaging. This technique allows an N pixel image to be produced with far less than N measurements and may have applications in LIDAR and microscopy.

Remote sensing

Ghost imaging is being considered for application in remote-sensing systems as a possible competitor with imaging laser radars (LADAR). A theoretical performance comparison between a pulsed, computational ghost imager and a pulsed, floodlight-illumination imaging laser radar identified scenarios in which a reflective ghost-imaging system has advantages.

X-ray ghost imaging
A ghost-imaging experiment for hard x-rays was recently achieved using data obtained at the European Synchrotron. Here, speckled pulses of x-rays from individual electron synchrotron bunches were used to generate a ghost-image basis, enabling proof-of-concept for experimental x-ray ghost imaging. At the same time that this experiment was reported, a Fourier-space variant of x-ray ghost imaging was published.

NASA also worked on Ghost imaging and found the beam splitter was not needed

A different approach allows us to dispense with such a beam splitter, transferring its function to the object itself. This is an advanced version of the famous Hanbury Brown Twiss intensity interferometer.