Radiometric Calibration Radiometric Calibration for the MAIA Laser for the MAIA Laser

ReceiverReceiver

Stacey R. SueokaStacey R. SueokaMentor: Robert NolanMentor: Robert Nolan

Supervisor: Don RuffattoSupervisor: Don RuffattoTextron SystemsTextron Systems

OutlineOutline

Textron Systems Textron Systems MAIAMAIA

• ImportanceImportance Laser rangingLaser ranging Radiometric MeasurementsRadiometric Measurements

• Laser and receiver systemLaser and receiver system Radiometric Calibration Radiometric Calibration

• In lab calibrationIn lab calibration• Plan for absolute calibrationPlan for absolute calibration

ConclusionConclusion

Textron Systems OhanaTextron Systems Ohana

Out of the 30 people working on Out of the 30 people working on Maui, one third were born and raised Maui, one third were born and raised herehere

Majority of Kauai Textron employees Majority of Kauai Textron employees were born and raised in Hawaiiwere born and raised in Hawaii

Also provides opportunities for Also provides opportunities for students like me to gain insight on students like me to gain insight on future technical occupations in future technical occupations in HawaiiHawaii

Textron ProjectsTextron Projects

Image processingImage processing Mount control systemsMount control systems Laser radar projectsLaser radar projects

• STSS STSS • HI-CLASSHI-CLASS• MAIAMAIA

MAIA LocationMAIA Location Maui Space Surveillance Site (MSSS)Maui Space Surveillance Site (MSSS)

Beam Director/Tracker Advanced Electro-Optical System

http://www.maui.afmc.af.mil/

Importance of MAIAImportance of MAIA

Customer - Air Customer - Air ForceForce• Space Situational Space Situational

Awareness Awareness

High repetition rate laser ranging

Radiometric measurements

RadiometryRadiometry Measurement of the intensity of Measurement of the intensity of

electromagnetic radiation electromagnetic radiation Used to characterize the satelliteUsed to characterize the satellite

Image by Philip Ronan

MAIA Laser ReceiverMAIA Laser Receiver

Telescope receives Telescope receives reflected light from reflected light from objectobject

Integrated into the Integrated into the optical subsystem optical subsystem of AEOS (coude of AEOS (coude room 4)room 4)

AEOS

http://www.maui.afmc.af.mil/

Receiver BoxReceiver Box Intensified Photo-Diode detectorIntensified Photo-Diode detector Reference DetectorReference Detector

Step 1: In lab calibration of the IPDStep 1: In lab calibration of the IPD

Optical table layout for calibration

Responsivity = Responsivity = average area average area divided by energy divided by energy per pulseper pulse

Energy read by IPDEnergy read by IPD

Responsivity = 1 ADU/ 50 PhotonsResponsivity = 1 ADU/ 50 Photons• Goal is 1 ADU/ 20 PhotonsGoal is 1 ADU/ 20 Photons• Efforts in progress to improve Efforts in progress to improve

responsivityresponsivity Using responsivity:Using responsivity:

• Divide IPD reading by responsivity to Divide IPD reading by responsivity to calculate energycalculate energy

Step 2: Plan for star calibrationStep 2: Plan for star calibration

How do we get there?How do we get there?• Select starsSelect stars

Check online database for Check online database for magnitudesmagnitudes

Determine exoatmospheric Determine exoatmospheric irradiance at 1064 nm using a irradiance at 1064 nm using a technique refined by NGST technique refined by NGST

Measure Stellar Signal at Several Measure Stellar Signal at Several Elevations (Air Masses)Elevations (Air Masses)• Determine extinction coefficientDetermine extinction coefficient• Calculate zero pointCalculate zero point

Conclusion Conclusion

Recap – What was accomplished :Recap – What was accomplished :• Learned about MAIA laser and receiver systemLearned about MAIA laser and receiver system• Worked on determining the responsivity of the Worked on determining the responsivity of the

receiverreceiver• Created a procedure for the absolute Created a procedure for the absolute

calibration using starscalibration using stars• Supported the optical integration of the Supported the optical integration of the

receiver into MSSSreceiver into MSSS Gained insight on astronomy and Gained insight on astronomy and

radiometryradiometry

AcknowledgementsAcknowledgements Textron SystemsTextron Systems

• Robert NolanRobert Nolan• Don RuffattoDon Ruffatto• Curtis KruppCurtis Krupp• Timothy GeorgesTimothy Georges• Chris MatsuuraChris Matsuura• Bob LercariBob Lercari• Nathan KimuraNathan Kimura• Wes UeokaWes Ueoka• Kelly KobayashiKelly Kobayashi

Air Force Research Air Force Research LaboratoryLaboratory

Maui Economic Maui Economic Development BoardDevelopment Board

Maui Community CollegeMaui Community College Institute for AstronomyInstitute for Astronomy Center for Adaptive Center for Adaptive

OpticsOptics• Lisa HunterLisa Hunter• Scott SeagrovesScott Seagroves• Hilary O’BryanHilary O’Bryan• Short Course Short Course

Instructors:Instructors: Dave HarringtonDave Harrington Jess JohnsonJess Johnson Ryan MontgomeryRyan Montgomery Isar MostafanezhadIsar Mostafanezhad

This work has been supported by the National Science Foundation Science and Technology Center for Adaptive Optics, managed by the University of California at Santa Cruz under cooperative agreement No. AST - 9876783.