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CALIPSO Commissioning Status

CALIPSO Commissioning Status. Carl Weimer, Lyle Ruppert, Justin Spelman – Ball Aerospace & Technologies Corp. CALIPSO Satellite is Operational On-Orbit. CALIOP Lidar “First Light”. Wide Field Camera. On-Orbit Program Structure.

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CALIPSO Commissioning Status

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  1. CALIPSO Commissioning Status Carl Weimer, Lyle Ruppert, Justin Spelman – Ball Aerospace & Technologies Corp.

  2. CALIPSO Satellite is Operational On-Orbit CALIOP Lidar “First Light”

  3. Wide Field Camera

  4. On-Orbit Program Structure • Principal Investigator is Dave Winker PI, co-PIs Jacque Pelon and Patrick McCormick; Payload Project Manager Kevin Brown • Satellite Operation Command Center (SOCC) is operated by CNES out of Toulouse • Mission Operation Command Center (MOCC) is operated by NASA LaRC out of VA • Ball is a partner for Payload operations • ASDC handling science data is at LaRC • Calibration/Validation Campaign coordinated out of Hampton University • Includes a Quid Pro Quo sharing of data between different ground and airborne systems with CALIPSO program • NASA LaRC has started flying its airborne High Spectral Resolution Lidar for validation studies

  5. Commissioning – Progress on Platform • Alcatel Proteus Spacecraft is fully operational • Survival Heaters functioning properly to protect Payload • Lithium Batteries are performing well (new to LEO) • S-Band communication system for Command and Telemetry is functional (Kiruna) • Hydrazine Propulsion system is functional and has been used • Power System is nominal – Currently 34 V to 36 V over an orbit – solar array mechanisms nominal • Nadir Pointing control held to required 0.08 degrees, achieving 600 m control on ground. • Orbit Corrections complete, CALIPSO is in the A-Train as of May 31 • Gyro Calibration Complete – Series of off-nadir rotations made, science data was collected to study ocean lidar return • GPS and Attitude (from Startrackers) Bulletins being provided to Payload for data geolocation • Spacecraft commissioning is complete

  6. Commissioning – Progress on Payload • Ball/NASA Payload is fully operational • Baseline plan of 45 days was met. Included extended period of outgassing and being powered off for spacecraft health checks and orbit correction maneuvers • Sequential approach was used to bring up each subsystem and verify its functionality • All subsystems powered up properly, power use agrees with predictions for each with minor variances • Thermal performance of subsystems has agreed well with pre-launch models. • Good thermal stability can be achieved within a day of powering off/on. Safe to Data Acquisition in 3 orbits. • Laser thermal balancing completed on June 9

  7. Different Views of Payload Wide Field Camera – BATC CT-633 Sun Shade X-Band Antenna Star Tracker Assembly - French X-Band Transmitter Payload Controller Laser Electronics Unit - Fibertek Imaging Infrared Radiometer -Sodern Lidar Receiver Electronics Integrated Lidar Transmitter - Fibertek lasers Receiver Power Supply

  8. Lidar Core – Transmitter and Receiver Adjustable Boresight Mechanism APD PMTs - LaRC Laser Radiator Optical Bench Laser Optics Modules Telescope Beam Expander Optics ILT (Integrated Lidar Transmitter) ILR (Integrated Lidar Receiver)

  9. Lidar Transmitter • Two redundant Nd:YAG lasers each capable of full mission life • 110mJ at both 532nm and 1063 nm @ 20 Hz • Lasers were delivered by Fibertek in 2002. Total of 80 million shots (4% of mission) fired during I&T • Laser has been operational since May 23, • 27 million shots on-orbit as of June 23 • Conductively cooled, thermal performance has been excellent – slight shift in operating points from those on ground indicating subtle thermal effects • O-ring sealed – pressure decay on units observable but meeting lifetime requirements • Following data shows energy stability starting on June 9 (last heater adjust) through June 21

  10. Laser Pulse Energy

  11. Lidar Receiver - Detectors • Photomultipliers (Parallel/Perpendicular – 532 nm ) and Avalanche Photodiode (1064 nm) are healthy • High Voltage power supplies showing excellent stability <0.1% over an orbit • Built in Test System (using LEDs) has verified sensitivity and timing response • Signal levels from Rayleigh are slightly higher than predicted based on radiometric math models of instrument • Detector noise levels pass requirements (outside of South Atlantic Anomaly) • Background light measurement made in high altitude regions is used to remove offset for each shot. Agrees with performance on ground.

  12. Etalon • 532 nm channel uses an etalon to limit bandwidth in order to reduce daytime background light • Etalon bandwidth is matched to laser linewidth – 0.035 nm = 35 pm = 37 GHz • Finesse of 18 • Etalon is a fixed, match-polished “sandwich” style made by Coronado, in a Ball mount. • Angle tuned and locked into place on bench. Temperature tunable over one linewidth on-orbit • On-orbit performance agrees with ground performance for both center wavelength and linewidth. • Uses main 532 nm lidar signal from upper-atmosphere to produce a steady signal to allow etalon to be tested

  13. Etalon Spectral Tuning – Raw Data

  14. Lidar Receiver - Data Processing • Onboard Data Processing of lidar data is functioning properly • Merge and Scale dual ADCs for each channel to achieve 23 bit dynamic range • Remove offsets and baselines (if needed) • Aligns all range bins – then performs vertical and horizontal averaging to reduce data volume • Calculates a reduced data set to downlink on S-band • Attaches all header information on a shot-to-shot basis – e.g. laser shot energy, pierce point lat/long, range to mean sea level, etc. • Achieves a lidar data compression of a factor of 25 • Requires high-performance rad-tolerant computer • First Flight of General Dynamics PC603 running at 160 MHz utilizing direct memory access and quad processors • Extensive Error Detection and Correction (EDAC) Algorithms are keeping up with radiation induced upsets, 5/day. • Memory testing shows no problems due to radiation or “weak bits”

  15. Lidar Receiver- Science Data Handling • Lidar Data is merged with the WFC and IIR data • Science Data • Stored in a 48 Gbit solid state recorder on Payload • Downlinked to Alaska (backup in Hawaii) over an X-band link once per day • United Space Networks receives and processes before shipping to NASA • Achieving >99% data throughput on X-band • 4.8 GByte/ Day delivered to NASA with 24 hour latency – looking into reducing this. • NASA ASDC is generating Level 1 with 24 hour latency • Command and Telemetry Data • Commands uplinked up to 6 times/day during commissioning (during normal ops, this has to be scheduled) • Stored on Platform • Downlinked on S-band to Kiruna • Delivered to LaRC with latency 30-45 minutes

  16. Lidar Transmitter/Receiver Alignment • Active Boresight Mechanism allows the lidar overlap function to be adjusted on-orbit • Goal is to use once to correct for shifts due to launch, thermal, humidity, and 1-g effects • Extensive testing on ground prior to launch including two full “atmospheric” tests • Adjusts pointing based on main lidar signal strength • On-Orbit - autonomous search algorithm succeeded in 4 minutes (requirement < 24 hours); fine align succeeded in 10 minutes (requirement < 20 minutes) • Alignment repeated multiple orbits to verify performance – results agreed within limits of algorithm – approximately 7 microrads – within requirements • More stability testing may be done later to look at different orbit times (different temperature gradients)

  17. Lidar Polarization Testing – Preliminary • Photomultiplier tubes are collecting cross-polarized data at 532 nm – • Primary objective is to distinguish water from ice clouds • Required extensive polarization design, testing and alignment of full system • Wedged quartz depolarizer mounted on a mechanism can be inserted into beam to calibrate the two channels • Residual instrument polarization effects < 0.7%, measured using Clear- Air depolarization from stratospheric Rayleigh scattering (25-35 km) • Depolarizer gain calibration has shown to be good to < 2% independent of scene the lidar is seeing • Final polarization characterization will be reported in future by Chris Hostetler (NASA LaRC)

  18. Summary • CALIPSO is up and running and in the science assessment phase • All subsystems are operating nominally • Design and performance information on CALIPSO is available from Ball to support Wind Lidar trades and development • See attached additional “Lidar First Light” images from Dave Winker • Acknowledgments: Thanks for Inputs from Dave Winker, Bill Luck, Bill Hunt, Mike Cisewski, Dave Rosenbaum, Alan Little, Rob DeCoursey, Dave MacDonnell, Ron VerHappen, from NASA Ryan Melton, Mike Wallner, Jim Leitch, Brian Johnson, and Leela Hill from Ball

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