MERIS Instrument Status

Transcription

1 MERIS Instrument Status presented by Stefan Weiß Photo: Courtesy Alcatel Space Industries Page 1

2 MERIS Instrument Status Functional Description & Hardware overview Functional check-out & Operations Telemetry Analyses Summary of Findings/Anomalies Conclusions Page 2

3 Functional Description Light from Earth and Atmosphere Sunlight Calibration Mechanism 5 Depolarizing Windows Reflectance Reference Generation of Calibration Signal Imaging Optical Module Slit Imaging Spectrometer 5 Cameras 2-dimensional CCD Detector Analogue Processing & 12 bit ADC [ VEU ] Power Distribution [ PDU ] Instrument Control Unit [ ICU ] DBU Digital Processing [ SDPSS ] Power Interface Operational Interface Measurement Data Interface Page 3

4 MERIS Hardware Overview Earth aperture Calibration mechanism Electronic equipments Optical bench Cameras Sun baffle Earth Cold space direction Radiators Flying direction Baseplate Page 4

5 Functional Checkout (1) ID Task Name 1 Launch March April May 10/02 17/02 24/02 03/03 10/03 17/03 24/03 31/03 07/04 14/04 21/04 28/04 05/05 01/03 2 Support modes 3 ICU Switch on 4 HEATER mode 5 Operation modes 6 Auxiliary modes 7 Measurement modes 8 CM opening 21/03 9 Calibration modes 10 Continuous, full MPS operation Page 5

6 Functional Checkout (2) All modes necessary for MERIS in flight operation have been checked out by proper commanding and detailed verification of the telemetry once the mode was achieved: LAUNCH, OFF, RESET/WAIT, STANDBY, STANDBY/REFUSE, HEATER, STABILISATION, PATCH COEFFICIENTS, AVERAGING, DIRECT & AVERAGING, ON GROUND CALIBRATION MERIS operation by full MPS continuously successful since begin of April Page 6

7 Telemetry Performance Analyses Per each mode: up to 360 Telemetry Parameters have been checked: (MERIS internal and MERIS related external parameters such as voltages, currents, temperatures digital status (software & relays), limits, settings) Commanding of the orbital parameters (spectral band programmation, gains etc.) and of the mechanism movements has been specifically verified Page 7

8 Calibration Mechanism Movement (see movie) Page 8

9 MERIS Sun Calibration MERIS Calibration in Orbit Page 9

10 Telemetry Performance Analyses Excellent performance of CCD temperature regulation: minor jumps by 20mK induced by VEU switching, performance impact negligible VEU temperature well within limits Optical bench temperature stable at 20 deg C [ C ] Comparison CCD3 Fine Temp. vs. VEU Temp., Day Dir&Avg Heater VEU CCD Time [ min ] Page 10

11 Anomalies/Findings ADA Exception triggering STANDBY REFUSE mode: probability one occurrence per 2 days range check error in ASW identified and corrected by SW patch ICU self test error due to SEU triggering STANDBY REFUSE mode: due to low probability (one occurrence per 500 days) no dedicated patch considered to be developped Overall SEU s in ICU memory as detected and corrected by EDAC: one occurrence per day in average, all memory locations equally affected Page 11

12 Conclusions 6 months of successful in-orbit operation, 5 months under full MPS control Efficient and fast checkout of functional performance (first 4 weeks), no degradation or changes since last on ground operations identified The efficiency of the design optimisations which have been introduced into the Flight Model Programme with respect to suppression of ghosts and straylight are proven now demonstrating the excellent in-orbit performance of MERIS MERIS overall health is in excellent state Page 12