CALIPSO Commissioning Status

1Working Group on Space-Based Lidar Winds, June 2006cweimer@ ball.com

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

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


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


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


Different Views of Payload

Integrated Lidar Transmitter -

Fibertek lasers

X-Band Antenna

Imaging InfraredRadiometer -

Sodern

Payload Controller

Star Tracker Assembly -

French

Lidar Receiver Electronics

X-Band Transmitter

Laser Electronics Unit - Fibertek

Receiver Power Supply

Wide Field Camera – BATC CT-

633Sun Shade


Lidar Core – Transmitter and Receiver

ILT (Integrated Lidar Transmitter)

ILR (Integrated Lidar Receiver)

Beam Expander

Optics

Adjustable Boresight

Mechanism

Laser Optics

Modules

Laser Radiator

PMTs - LaRC

Telescope

Optical Bench

APD


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


Laser Pulse Energy

CALIPSO LOM 2 Performance

1

1.01

1.02

1.03

1.04

1.05

1.06

1.07

1.08

1.09

1.1

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73 76 79 82 85 88 91 94 97 100 103 106 109

S-band Contacts

110.00

112.00

114.00

116.00

118.00

120.00

122.00

Energy Ratio ENG_MON_1064 ENG_MON_532P Total Energy / 2

CTA Heater Adjustment

532

Green / Red

1064

Total Energy

Green + Red

X band Relay Coordination Anomaly


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.


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


Etalon Spectral Tuning – Raw Data


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”


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


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)


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)


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

Documents

CALIPSO Commissioning Status