Download Some CNES activities on optical telemetry and proposals for

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;
 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)
Simulation of atmospheric turbulence
on Earth-Space links:
The TURANDOT software
TURANDOT: Basics
 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
TURANDOT simulations
input parameters:
Refraction index strcuture parameter Cn2 (m-2/3)
 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)
 Outputs:
 FFP
 Auto-control
Air interface, PAT
No turbulence (downlink)
Turbulence profile
Distance in atmosphere (km)
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°
Further works

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
CNES Optical telemetry demonstrator
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
SOTA (NICT) on board SOCRATES (JAXA)
NICT/CNES MOU
1.06 μm
1.55 μm
NRZ
1Mbps or 10Mbps
MéO (OCA)
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 LEOground 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.
CNES proposals for optical TM links standards
Jean-Luc Issler,
Géraldine Artaud
CNES proposals for CCSDS Optical Com BOF
- Standardization is required for global OGS-networks compatible with LEODTE, due to the need of interoperability specified by OLSG/IOAG/IOP
- We propose 3 blue book sets, in agreement with OLSG/IOAG/IOP needs
• 1) One set for the High Photon flux
• 2) One set for the Low photon flux
• 3) A book for atmospheric data exchanges (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 shall be considered at the same level and with the same
global time line than other scenarii in all books
- This stay true in the case of a generic standard for links through atmosphere : such a
generic standard would have to take into account the dynamics of LEO DTE links
10
Other CNES recommandations for Optical TM link standardisation
-
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 CONOPS 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
11
BACK UP SLIDES
For IOAG (OLSG,…)
15 august 2012
12
REFERENCE ARCHITECTURE OF A LEO DTE OPTICAL TM LINK
Beacon
Pointing
Acquisition
Tracking
Injection
In fiber
Amplification
filtering
Demodulation
Amplification
Décoding
Deframing
filtrage
Ground station
Telescope
Propagation
Télescope
collimation
Amplification
filtering
Modulation
Coding
Framing
LEO terminal
Pointing
Acquisition
Tracking
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).
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
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
IOAG Catalog-1 Return Data Delivery Service
17
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 beeing high data rate links, the level 2
CCSDS protocol (data link layer) to use is AOS (732.0). That is
transfert frames of fixed length (for a given mission, the maximum
length selectable is about 2000 bytes).
This protocol is adapted to high data rate links. That is not the
case for TM space data link protocoal, which is adapted for
medium and low data rate TM.
Therefore, the OAS protocol is recommanded by CNES for optical
telemetry links, including Direct To Earth (DTE).
IOAG/OLSG/IOP doesn’t recommand redevelopment of a level 2
protocol for optical space telemetry. CNES fully support that
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IOAG Catalog-2 Data Delivery Service
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Identifications of IOAG catalog service wich can be reused for
optical high data rate telemetry : Internetworking for DTN
Regarding level 3 protocols (network) and level 4 (transport), the
DTN protocol suite in developpement at CCSDS is attractive for
optical links since DTN, for instance, manage hand-over from
one station to the other and automatic retransmissions of data
not correctly received on the ground.
These two functionnalities will be very interestings for optical
links, like the ones through the earth atmosphere and its clouds.
Therefore, the DTN protocol is recommanded by
OLSG/IOAG/IOP to be considered and studied for optical links,
including Direct To Earth (DTE), before any recommandation for
a new development of a level 3 and 4 protocols. CNES fully
support that
20
Conclusions of the Space Optical Communication
Workshop in Berlin the 17th of may 2011
850 nm
1064 nm
1550 nm
Antenna size
Data rate (including
WDM consideration)
Availability of COTS
Atmospheric
attenuation
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.
Turbulence
Background light
Optics quality
requirement
Good
EYE SAFETY
TRL (*) (**)
Year
dependent
Year
dependent
Year
dependent
* 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
Fair
Poor
** 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, …
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.
22
Exemples of binoculars used by astronauts,
minoring assumptions to be considered
for EYE SAFETY studies
Unigadget sellings
« The Zoom Binocular with Recommended by
Captains and Astronauts
20-144x70mm ».
Leica Trinovid 8x42 and Trinovid 10x42 Binoculars
« NASA sent a Trinovid binocular with astronauts on
a lunar exploration mission on Apollo 11 in 1969 »
Meopta Meostar 12x50 WP
.>x20
x12
« Meopta’s binoculars and spotting scopes are used by astronauts »
Exemples of IR magnifing night vision devices
( some are helmet mountable )
Manufacturer : Excelis