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Some CNES activities on optical telemetry and Proposal for CCSDS Optical Com BOF

Some CNES activities on optical telemetry and Proposal for CCSDS Optical Com BOF. J-L. Issler October 2013 San Antonio. CNES Milestones for optical telemetry. Operationnal optical telemetry system ( LEO  DTE ) Ka band DTE could not meet all data throughput future needs;

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Some CNES activities on optical telemetry and Proposal for CCSDS Optical Com BOF

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  1. Some CNES activities on optical telemetryandProposal for CCSDS Optical Com BOF J-L. Issler October 2013 San Antonio

  2. CNES Milestones for optical telemetry • Operationnal optical telemetry system ( LEO  DTE ) • Ka band DTE could not meet all data throughput future needs; • In flight demonstration with an on-bord terminal in about 2020 • All system validation tools will be available • Validation of technologies (amplifiers, detectors, …) • Validation of ground/board configurations close to an operational standardised case • Standardisation of optical communications completed in 2020 • As needed by Optical Link Study Group (OLSG), IOAG, IOP 2020 • Demonstration of some issues related to LEO DTE optical telemetry with a real link in 2015 • Développement of on bord technologies (on-going for a few key technologies) • Technical studies of ques de transmission (on going) • Study and modeling of propagation channel (on going) • System studies (on going)

  3. PILOT scientific software developed previously at ONERA/DOTA (“wave optics”); From PILOT to TURANDOT (funded by CNES): interface suitable for both PLTM and Telecom simulations (Far Field Pattern on both the uplink and the downlink ) & automatic dimensioning & control  engineering tool for turbulence simulation (main output: Far Field Patterns) 2 simulation modes: Snapshots: no time correlation  long term statistical assessment Temporal: time correlation between 2 successive FFP Simulation of atmospheric turbulence on Earth-Space links:The TURANDOT software TURANDOT: Basics

  4. Air interface, PAT No turbulence (downlink) TURANDOT simulations • Outputs: • FFP • Auto-control input parameters: • Simulation mode & random seed • Uplink / downlink • Number of output FFP (D < 1 s in temporal mode) • DTx, DRx, waist & divergence + pixel size in the Rx plane • 0.8µm <  < 1.55 µm • Vsat, Dsat,  > 5° (validated for > 20°) • Hobs, Altobs • Wind speed, Cn2 profile or Cn2 at reference altitude + Hufnagel Valley profile • Optional: Phase aberration (static), Pointing errors (temporal sequence) Turbulence profile Refraction index strcuture parameter Cn2 (m-2/3) Distance in atmosphere (km)

  5. TURANDOT: Validation • Validation with respect to reference cases: • Analytical models when available: Rytov for downlink & weak turbulence in particular • Cross validation with experimental results: OICETS results published by NICT well reproduced by Turandot simulation for the 23.5° & 35.1° cases  ONERA/NICT/CNES paper at ICSOS conference • TURANDOT validated for elevation angles > 20°

  6. Atmospheric absorption & clouds/aerosol attenuation:MATISSE software • Ground network optimization(w.r.t. to macroscopic availability): •  optimization tool using cloudiness maps provided by Satmos • Ground based radiometric measurements for cloudiness & LWP mapping • Turbulence effects:On-going R&T activity to extend TURANDOT down to 10° elevation angles + Cn2 profiles measurements Further works

  7. CNES Optical telemetry demonstrator SOTA (NICT) on board SOCRATES (JAXA) 1.06 μm 1.55 μm NRZ 1Mbps or 10Mbps MéO (OCA) Goals for 2015 : • Establish an LEO to ground optical link ( pointing, acquisition, tracking ) • Measurements of the propagation environment effects of turbulances, • Evaluation of telecom performances at low data rate to start with NICT/CNES MOU

  8. A clear worldwide trend for specifically designed LEO DTE optical link experiments : 1550 nm downlinks The mentioned advantages of 1550 nm are widely admited for LEO-ground direct links, since all the described on board equipments presently specifically designed for LEO to ground direct links only (DLR/BIROS/OSIRIS; NICT/SOCRATES/SOTA, ESA/Optel-mu, NASA/JPL on bord terminal, NASA/ on bord ISS …) should use 1550 nm downlink in the years to come (: for the LEO to ground specific high data rate telemetry link) for in orbit demonstrations. For its experiment thanks to JAXA and NICT, CNES will use a 1550 nm LEO DTE downlink. The 1064 nm uplink is used do to the SOTA terminal design, but CNES will use 1550 nm uplinks for its future demonstration representative of an operational system.

  9. CNES proposals for optical TM links standards Jean-Luc Issler, Géraldine Artaud

  10. CNES proposals for CCSDS Optical Com BOF - Standardizationisrequiredfor global OGS-networks compatiblewith LEO-DTE, due totheneedofinteroperabilityspecifiedby OLSG/IOAG/IOP - Wepropose 3bluebooksets, in agreementwith OLSG/IOAG/IOP needs • 1) Onesetforthe High Photon flux • 2) Onesetforthe Low photonflux • 3) A bookforatmosphericdataexchanges (including CON-OPS optimisations) • Bleue book sets 1 and 2 are recommanded to be : • One bleue book for frequency, modulation, beacons, PAT, … • One bleue book for coding and interleaving • LEO DTE scenario shallbeconsideredat the samelevel and with the same global time line thanother scenarii in all books • This staytrue in the case of a generic standard for links throughatmosphere : such a generic standard would have to takeintoaccount the dynamics of LEO DTE links

  11. CCSDS should concentrate on physical layer (:layer 1), since existing protocol (layer 4, 3 & 2 ) are suitable, according to OLSG/IOAG/IOP. CNES fully support that • OLSG identified a preliminary CON-OPS for optical links throught atmosphere : the site selection is made thanks to centralised meteorological data set. CNES think that the CON-OPS could be optimised in combining use of centralised meteo data and local “sky event” data ( aircraft and cloud data ). • CNES support the idea of having reference atmospheric propagation model(s) for turbulances, scintillations, ... To allow true comparisons of different codings, interleavings, … standard proposals. Therefore, mutualisations of models and measurements seems to be needed for CCSDS • CCSDS should consider with OLSG eye safety issues for its works on frequencies Other CNES recommandations for Optical TM link standardisation

  12. BACK UP SLIDES For IOAG (OLSG,…) 15 august 2012

  13. REFERENCE ARCHITECTURE OF A LEO DTE OPTICAL TM LINK Beacon Pointing Acquisition Tracking Pointing Acquisition Tracking Télescope Telescope Injection In fiber collimation Propagation Amplification filtering Amplification filtering Modulation Coding Framing Demodulation Décoding Deframing Amplification filtrage Ground station LEO terminal

  14. OICETS measurements • 2 elevations • Urban area line of sight: unstable Cn² profile + HV (Cn²(ground) = 3,5 10-13 m-2/3 • 5 cm pupil area, APD detector OICETS NICT optical ground station (1.5-m optical telescope) *Morio Toyoshima, Hideki Takenaka et al. Frequency characteristics of atmospheric turbulence in space-to-ground laser links, Proc. SPIE 7685 (2010).

  15. Validation w.r.t. OICETS Power Spectral Densities Normalized temporal covariance θ = 23,5° Coherence time : Measured ~ 500 µs vs TURANDOT ~ 600 µs Excellent agreement

  16. Validation w.r.t. OICETS Power Spectral Densities Normalized temporal covariance θ = 35,1° Coherence time: Measured ~ 400 µs vs TURANDOT ~ 380 µs Excellent agreement

  17. IOAG Catalog-1 Return Data Delivery Service

  18. Identifications of IOAG catalog service wich can be reused for optical high data rate telemetry : Return Channel Frames Services : AOS for optical High Data Rate Telemetry • Optical telemetry links beeinghigh data rate links, the level 2 CCSDS protocol (data link layer) to use is AOS (732.0). That is transfert frames of fixedlength (for a given mission, the maximum lengthselectableis about 2000 bytes). • This protocolisadapted to high data rate links. That is not the case for TM space data linkprotocoal, whichisadapted for medium and low data rate TM. • Therefore, the OAS protocolisrecommanded by CNES for opticaltelemetry links, including Direct To Earth (DTE). • IOAG/OLSG/IOP doesn’trecommandredevelopment of a level 2 protocol for opticalspacetelemetry. CNES fully support that

  19. IOAG Catalog-2 Data Delivery Service

  20. Identifications of IOAG catalog service wich can be reused for optical high data rate telemetry : Internetworking for DTN • Regardinglevel 3 protocols (network) and level4 (transport), the DTN protocol suite in developpementat CCSDS isattractive for optical links since DTN, for instance, manage hand-over from one station to the other and automaticretransmissions of data not correctlyreceived on the ground. • Thesetwofunctionnalitieswillbeveryinterestings for optical links, like the onesthrough the earthatmosphere and itsclouds. • Therefore, the DTN protocolisrecommanded by OLSG/IOAG/IOP to beconsidered and studied for opticallinks, including Direct To Earth (DTE), beforeany recommandation for a new developmentof a level3 and 4 protocols. CNES fully support that

  21. Conclusions of the Space Optical Communication Workshop in Berlin the 17th of may 2011 This table was elaborated by all the participants*** to the 17 may 2011 workshop. Discussion occured for the criteria and the colors, and the quasi-consensual obtained result as presented at the end of the workshop is shown here. * TRL estimations agreed in the Optical Space Communication workshop are for Rb>1 Gbits/s in 2011 : For 850 nm : 5 ; for 1066 nm : 9; for 1550 nm : 6 ** Which TRL in 2015 ? 2020 ? 2025 ? 2030 ? 2035 ? 2040 ? 2045 ? 2050 ? etc … *** DLR, JAXA, ESA, NASA, CNES, MIT-Lincoln Lab, DIN, HHI-Fraunhofer, RUAG-Space, TU Gratz, Tesat, Carl Zeiss Optronics, …

  22. SOME EYE SAFETY CONSIDERATIONS - Some military plane & helicopter pilots, parachutists, pedestrians, … have nigh vision magnifying helmets (see slide 4). This as to be considered (for instance) for operations close to the uplink of OGSs- Some aerial crafts are not moving quickly : helicopters, ballons, … : important for spacecrafts not « moving quickly » like GEOs - the future GEO-telecom powerfull optical links shall be considered by civil aviation (+helicopters+ballons+ … ) authorities for eventual update of eye safety computation methods ( same remarq for space agencies managing astronauts ). We have to ensure that the EYE SAFETY methodology updates proposed to the concerned authorities are compatible with commercial and non commercial space laser transmissions.- some animals have night vision ( NB : CNES already received an « ecological » question related to space laser transmissions )- atmospheric scintillations should be considered in EYE SAFETY worst case computations related to space   earth optical transmissions- For the long-term, a wide diversity of astronaut altitudes have to be considered (LEO, moon-transfert*, moon orbit*, moon surface*, asteroid transfert, GEO ?(an Apollo mission option was in GEO), HEO ? ** ). Proximity operations or rendez vous with a laser transmiting spacecraft has to be considered- Astronauts have a helmet provided with a sliding sun mask : EYE sefety shall be considered with and without using the sun mask.* : 2025 ? ** Nota Bene : some space agencies road maps forsee quasi generalised usage of optical links for HDRTM in 2040. The 2040 situation has therefore to be choosen to consider worsk cases for EYE SAFETY studies.

  23. Exemples of binoculars used by astronauts, minoring assumptions to be considered for EYE SAFETY studies Leica Trinovid 8x42 and Trinovid 10x42 Binoculars Unigadget sellings « The Zoom Binocular with Recommended by Captains and Astronauts 20-144x70mm ». « NASA sent a Trinovid binocular with astronauts on a lunar exploration mission on Apollo 11 in 1969 » Meopta Meostar 12x50 WP x12 .>x20 « Meopta’s binoculars and spotting scopes are used by astronauts »

  24. Exemples of IR magnifing night vision devices ( some are helmet mountable ) Manufacturer : Excelis

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