NEW LEVEL OF ACCURACY IN TIME TAGGING IN SPACE
Applications
The capabilities offered by picosecond-precision Time Tagging, alias Event Timer, allow for significant improvement of measurements already being performed by other techniques as well as open possibilities for novel measurements in Science & Applications Domains. For example, Optical Gravimetry, Optical Time Domain Reflectometry, and Optical Gyroscope for Rotation Measurements.
The STTT can be manufactured into a space grade timing device for embedding into several systems/subsystems to provide all these major functions simultaneously operating on-board of a satellite:
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Laser Altimetry for Space Applications
Laser Altimetry is the direct extension of the highly developed Ranging technique, involving laser mapping of specific target areas, as for landing sites or land (resources) mapping & management, etc.
In 2016 Eventech was awarded with ESA contract for technology transfer for space applications and in 2017 was introduced by ESA to Neptec UK Ltd. (current MDA UK Ltd.), who invited Eventech to ESA & Roscosmos moon mission “Luna-27” to build TDC for Neptec LiDAR system. The reason is that there are no <10ps TDC available on the space market and only Eventech solution can be applied even though only EQM was finalized as a result of Eventech ESA contract. The conventional design of Eventech Event Timer made it possible to easily integrate it into the Neptec LiDAR and successfully test it.
Currently, Eventech is working for ESA with EFACEC (Pt) supplying a space-qualified Event Timer processor for a HELENA Laser altimeter, foreseen to fly aboard the HERA spacecraft foreseen for Asteroid mapping. Evenetch will provide the LIDAR and Altimeter specified Timing Module (LSTM) Engineering Model, based on the Qualification Model MPET (ESA Contract No. 4000115326/15/NL/Nde with Eventech Ltd), to satisfy the requirements of size and power consumption for Planetary Altimeter HELENA Project by moving the technology of interpolation and input commutation inside the FPGA, preserving high standards of the original Timer’s precision.
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Laser Imaging for Space Applications
Combination of an Array-detector with a Scanning or Flash LiDAR is an important perspective application for Eventech Event timer: the picosecond accuracy/resolution combined with a small (≈ nsec) dead time allows for photon time tagging with the high signal-to-noise ratio. Eventech is funding, as part of his R&D program development for an Imaging lidar for envisaged space applications. This will be the 1st demonstration of time tagging picosecond technique for an imaging lidar.
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Clock Distribution & Synchro in Free Space (e.g. among Satellites)
For Optical and RF Telecom satellites, the Space Time Tagging Technology can relax the Ground Stations requirements in terms of density and coverage by providing in Orbit picosecond precision/accuracy clock distribution for timing and synchronization. An internal study is looking at the Trade-offs for this type of application.
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Laser Communication by Pulse Position Modulation
The Pulse Position Modulation (PPM) is one of the approaches to data transmission. In optical communication, the PPM allows to transfer data with low energy consumption. In this method, N bits of information are encoded by transmitting a single laser pulse with one of 2N time delays relative to the previous one. With average delay of T seconds, the transmission speed is N/T bits per second on average. Reduced dead time of the system allows for shorter minimum delay and consequently shorter T, and increased precision allows encoding data with less difference between time delays, which means either more bits encoded with the same T, or shorter T for the same number of bits per pulse.
The Laser Communication by PPM requires precise STTT and can be used as Deep Space communication solution.
Quantum Communication
Exploiting Eventech timer unique performance characteristics allows to use it as a precious tool for many quantum optical measurements via Coincidence Correlation or Time tagging. Again, interferometric optical schemes as used for other envisaged application can be used: here specifically with the Hanbury Brown Twiss interferometer. Unique measurements capabilities can be applied here for:
➢ QKD (key distribution)
➢ QDS (digital signature)
➢ QE (entanglement)
➢ QT (Teleportation)
➢ QIP (Information processing)
➢ Photon Antibunching (identifying single-photon-emitter)
Eventech engineers and experts can discuss specific customer’s requirements and needs.