SIMIS A multimissions tool for management of stations visibility

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SIMIS A multi-missions tool for management of
stations visibility

• P. MICHEAU, N. BATAILLE, B. DAVOINE
• CNES, Toulouse, FRANCE

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Summary

• Historical survey
• CNES involvment in mini/micro-satellites
• TTC needs for mini/micro-satellites
• ICONES project
• Presentation of SIMIS tool
• Main functionalities
• Development principles and features
• Scheduling algorithm
• Miscellaneous tools
• Examples of SIMIS use
• Nominal case for station network designing
• Degraded case long-run unavailability of a
  station
• Preparing future operations
• Conclusions

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CNES involvment in mini/micro-satellites

• Initial context to develop (cheaper, better,
  faster) lines of products for satellite platforms
  
• Planning of launches
• mini Jason (12/2001), Calipso (03/2005), Corot
  (mid-2006), SMOS (2007)
• micro Demeter (06/2004), Essaim Parasol
  (10/2004), Microscope (end 2006)

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TTC needs for mini/micro-satellites

• Mini/µ satellites needs for ground-satellite
  visibilities
• Telemetry payload TM (long durations, mainly
  X-band but partly in S-band) and housekeeping TM
  (S-band)
• TM / TC new CCSDS protocols
• Increasing load upon old CNES 2 GHz network
• priority for SPOT/HELIOS family
• CNES involvment in LEOP or punctual support to
  other space operators
• Network Optimisation Study (2000 --gt beginning
  2001)
• CNES decision to create a new project (ICONES
  Infrastructure de Communications Optimisée pour
  les NouvEaux Satellites), with dedicated S-band
  network to develop

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ICONES project

• ICONES main components
• S-band stations dedicated, generic TTCET
  (Telemetry,TeleCommand Earth Terminal) and/or
  baseband kits on existing 2 GHz stations
• RTD data transmission network
• ARAMIS operational reservation center for
  station overflies
• SIMIS mission analysis tool
• Planning for stations
• 1 TTCET in AUS (near Toulouse, France) JASON
  dedicated , ready since 2001
• 1 TTCET in AUS first multirange (mini/µ)
  station driven by Demeter project reception
  achieved beginning 2003
• 1 TTCET in Esrange (near Kiruna, Sweden named
   KRN ) initial need for  polar  station
  driven by  2004-satellite-peak  reception
  achieved June 2003
• 1 kit in HBK (near Pretoria, South Africa, on
  existing antenna facilities) driven by next
  mini/µ sat , especially for LEOP first
  adaptations in April 2004 for Calipso.

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SIMIS Main functionalities

• Purpose to define and to check the design
  (number and position) of TTCET/kits network,
  relatively to visibility needs and constraints
  for satellites.
• 4 main functions
• to generate a priori pass-planning files
  (dates of beginning/end of visibility AOS/LOS)
• definition of satellites (orbit parameters),
  antennas (position and masks), period of study
• to achieve first sortings on these fly-bys
• for given satellite minimum duration, antennas
  to consider , track position relatively to
  antenna, ...
• for given antenna opening nominal hours and
  operational availability
• to achieve scheduling of these flybys , which
  are compliant with given constraints
• for a given satellite or antenna total required
  visibility duration and total number of flybys
  required, on specific time slots minimum,
  maximum
• minimum and maximum time between two successive
  visibilities
• priority of antennas reservation for given
  satellite
• to display results in a convivial form
• statistics on final visibilities ( by group of
  satellites or of antennas, )
• time-dependant evolutions of characteristics
  (number of considered flybys for given satellite,
  durations of visibilities, )
• orbit ground tracks , with identification of
  retained visibilities segments
• All these functions may be activated
  independantly , or linked for 2 or 3 out of the
  first 3

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Development principles and features

• Principles
• easy-to-use human-machine interface
• heart of SIMIS scheduling algorithm
• CNES software inheritance (in space dynamics,
  mathematics, ...)
• milestone towards future operational reservation
  software (ARAMIS)
• Features
• Development team THALES IS
• Operating System Linux Redhat V7.2
• Programming languages C, Fortran
• Conception tools Rational Rose / UML
• CNES library MSLIB, Madona, Genesis, Xtrace
•  Ilog Solver  software used under licensing
  agreement
• Planning development from April to October 2002

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Scheduling algorithm
Scheduling algorithm

• Optimisation problem to find at least one
  solution matching all constraints concerning
  satellites needs and antennas availabilities for
  visibility on a given study period .
• 9 types of constraints managed by Ilog Solver
  duration and number of visibilities (min/max, for
  each visib. or for some given slots of time)
  imposed visibilities duration between visib.
• Splitting of study period into smaller
   programmation horizons  (about 24h to 48h),
  with management of constraint continuity between
  two successive horizons.
• Help to user in case of non-convergence of
  algorithm (indication on saturated constraints
  and possibility to skip to following horizon and
  to investigate later )

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SIMIS miscellaneous tools

• Post-processing tools statistics comparaison
  of files
• Orbit ground tracks
• recuperation of ephemeris for different
  satellites
• visibility masks of antennas
• final retained visibility segments in color

9 / 18
SpaceOps Conference - May 17-21, 2004 - Montréal,
Canada
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SIMIS screen examples
SIMIS screen examples
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Example of SIMIS use
Example of SIMIS use

• Purpose to study network design for CNES
  mini/µ-satellites up to 2007
• Context
• Foreseen satellites Demeter, Calipso, Parasol,
  Corot, Microscope, SMOS
• TTCET antennas AUS, KRN requirements
  Demeter/AUS and Calipso/KRN only Corot priority
  on KRN.
• Constraints for some satellites minimum number
  of passes per day, minimum cumulative duration of
  visibility per day.
• 2 main cases
• nominal (100 availability for antennas)
• degraded (breakdown of KRN _the most loaded_
  antenna)

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Results in nominal case (1)
Results in nominal case (1)

• (Satellite requirement in brackets)
• Satellite Flyby number by
  day Cumulative visib. duration
  (/day)
• Min. Mean Max. Min. Mean Max.
• Demeter 3 (4) 3.9 4 24()(30) 30 33
  
• Calipso 4 (4) 4.1 5 30(26) 34 41
• Parasol 2 (2) 2 2 15(14) 17 19
• Corot 4
  5.7 6 41(40) 44 46
• Microscope 1 (1) 1.1 2 3.6 6.4 9
• Smos () () 2 (2) 2 2 12 19 20

() mismatch due to unicity and to low latitude
of antenna required (AUS) for Demeter
altitude () () SMOS needs station on left
sideof ground track when going ahead
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Results in nominal case (2)
Results in nominal case (2)
Demeter passes per day Number of passes
Visibility duration (min)
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Degraded case long-term unavailability of a
station (1)

• Context KRN TTCET with long-duration
  unavailability we want to check if HBK kit is
  necessary in routine phase
• First results with AUS alone (requirement for
  minimum in brackets)
• Satellite Flyby number by day Cumulative
  visibility
• duration (min/day)
• Min. Mean Max. Min. Mean Max.
• Demeter 3 (4) 3 (4) 3 18 (24) 23 (30) 26 (30)
• Calipso 2 (4) 2 (4) 2 6 (26) 14 (26) 19 (26)
• Parasol 2 (2) 2 2 6 (14) 13 (14) 18
• Corot 2 3.6 4 16 (40) 30 (40) 38 (40)
• Microscope 1 (1) 1 1 3 7 9
• Smos 1 (2) 1 1 4 8 10
• So, even for mean or max values, there are
  mismatches with AUS alone

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Degraded case long-term unavailability of a
station (2)

• With help of HBK kit (for minisatellites only)
• Satellite Flyby number by day Cumulative duration
  visib. (min/day)
• Min. Mean Max. Min. Mean Max.
• Demeter 3 (4) 3.9 4 24 (30) 29.4 33
• Calipso 3 (4) 4 4 24 (26) 29 33
• Parasol 2 (2) 2 2 12 (14) 17 19
• Corot 4 5 6 30 (40) 40 46
• Microscope 1 (1) 1 1 3 7 9
• Smos 2 (2) 2 2 13 17 19
• Antenna Antenna load in
  visibilities Mean
  visibility
• 
  number by day
  duration by day
• Min. Mean Max.
• AUS 12 14 16 1.8 h
• HBK 2 3.7 6 29 min

• Improvement with HBK (requirements met for mean
  values) this study allows to initiate a
  trade-off between actual satellite needs and
  necessity to buy another station

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Preparing future operations

• Next step ARAMIS operational tool (for
  stations reservation )
• Generic schema
• Some SIMIS functionalities will be recuperated
  scheduling algorithm, sortings and synthesis.
• New implementations agendas/plannings for
  operations, advanced human-machine interface.
• , ...

Visibility needs and constraints
Stations status
Stations
Command-control Centers
lt- Pass-plannings, TC,--- pointing files
ARAMIS
lt----- scheduling --------
----Orbit parameters ---gt
-------------TM ----------gt
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CONCLUSIONS

• SIMIS tool was necessary due to various needs
  for satellite visibilities on a limited station
  network
• Modular development and exploitation, like a
  toolbag
• Very useful for help to decision for buying
  new stations or for checking visibility
  requirements matching.
• Stands as a prototype (for its algorithmic part)
  for future operational reservation software (to
  arrive mid-2004).