Prototype for 3D LIDAR image acquisition will be used in space missions

INESC TEC’s Centre for Applied Photonics (CAP) has concluded the first prototype of a system with Light Detection And Ranging (LIDAR) technology, which measures the properties of reflected light in order to obtain information, such as distance and the 3D shape of a certain object. The system can be used for probe landing, for robot navigation on the surface of planets and for collecting and transporting soil samples, and it should be used in space shuttles in the next missions to explore planet Mars. The prototype was developed as part of project CYCLOPS, which joins INESC TEC and the European Space Agency (ESA).

Sensor with a pixel that captures 3D images with a resolution of 1024x768

Lighter, more compact, effective and sustainable, the LIDAR (which is similar to a radar, but with laser radiation) was developed based on a revolutionary theory called compressive sensing, and it can measure distances and capture 2D and 3D images with a resolution of 1024 by 768 pixels.

The technology is different from conventional systems not only because it has no mobile parts, (which is advantageous in space applications as it places no alignment, vibration or lubrication problems, for instance), but also because it does not sweep the area to be inspected and it has a sensor with just one pixel that makes it possible to obtain images with 1024 x 768 pixels without requiring as many measurements as usual. “Another advantage is the possibility of miniaturising the sensor, substantially reducing the mass and energy used, and enhancing the number of applications and space missions”, adds João Pereira do Carmo, Technical Officer at ESA.

The use of this system, developed by CAP researchers Filipe Magalhães and Francisco Araújo, will make it possible to identify the best location for space shuttles to land on the Moon or on Mars, by analysing the terrain’s topography, based on image acquisition and on the respective distances found for each pixel in the image. The robots that will be exploring the surface of the planet can also detect obstacles and move more easily thanks to the potential of this system. Furthermore, the prototype can also make it easier to collect and carry samples from Mars to Earth, by locating the exact position of the orbited capsule with the samples.

However, the system is not limited to the exploration of planets or astronomical objects; it can be used in more common scenarios, such as to conduct land surveys, in autonomous vehicle navigation or in military applications (such as vision through camouflage or night vision.

For now, the laboratorial prototype is being used simply as proof of concept, but in 2018 the system could step on Mars. By that time, the system will have to be adapted to the adverse conditions of the Red Planet, such as extremely low temperatures, sand storms and strong winds. “The electronic, optical and mechanical components should meet temperature, radiation and vibration requirements which are typical of space missions. These components are usually produced for temperatures that can vary between -20ºC and 40ºC, but in space those temperatures can range between -100ºC and+300ºC; therefore, it is necessary to use special components that can withstand these operation ranges”, explains Filipe Magalhães, researcher at CAP.

INESC TEC is one of the few institutions in the world working on the use of this technology in space exploration and is now competing with several entities that want to have their technology associated with space exploration. And this is a market of infinite possibilities. According to João Pereira do Carmo, “The inexistence in Europe of high resolution detectors to obtain 3D images (such as those required for the space applications mentioned above) and the high costs that come with developing these systems have led the ESA to promote alternative solutions with high potential such as that proposed  by INESC TEC”.

This is not the first time the Associate Laboratory develops a project in the space area and in another occasion the ESA has already chosen INESC TEC to create solutions that can be adapted to aerospace engineering. An example of that is the ESA-ONE, a European project to monitor carbon dioxide in the atmosphere.

The system’s second stage of development will start next year

The prototype was developed as part of project CYCLOPS (the system has a detector with a single pixel, a reference to the one-eyed giants of Greek mythology), whose main goal is to develop a system to obtain LIDAR images using a single pixel camera based on compressive sensing. This will be used in space missions, specifically in Mars. The project involves exclusively the researchers at INESC Porto and the European Space Agency.

INESC TEC will start the innovative system’s second stage of development in the beginning of 2014. In this next stage, the researchers hope to develop a system with a higher level of technological maturity (TRL 4 or higher) and, as a result, a system that will adapt better to the demands of space operations. “It should also be faster, more compact, lighter and require less power”, Filipe Magalhães reveals.

By that time, the project, which is now being developed exclusively by INESC TEC and the ESA, should also be supported by company EFACEC, which also specialises in aerospace developments.