MARSCHALS: a new airborne millimetre-wave limb-sounder for the UTLS COST UTLS Workshop ESTEC, 11-13 March 2004 Victoria Jay, Brian Kerridge, Jolyon Reburn, Richard Siddans, Brian Moyna, Matthew Oldfield, Dave Matheson Earth Observation and Atmospheric Science Division, SSTD
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Victoria Jay, Brian Kerridge, Jolyon Reburn, Richard Siddans,
MARSCHALS: a new airborne millimetre-wave limb-sounder for the UTLS COST UTLS Workshop ESTEC, 11-13 March 2004. Victoria Jay, Brian Kerridge, Jolyon Reburn, Richard Siddans, Brian Moyna, Matthew Oldfield, Dave Matheson Earth Observation and Atmospheric Science Division, SSTD - PowerPoint PPT Presentation
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MARSCHALS: a new airborne millimetre-wave
limb-sounder for the UTLS
COST UTLS WorkshopESTEC, 11-13 March 2004
Victoria Jay, Brian Kerridge, Jolyon Reburn, Richard Siddans, Brian Moyna, Matthew Oldfield, Dave Matheson
Earth Observation and Atmospheric Science Division, SSTD Rutherford Appleton Laboratory
Introduction
• MARSCHALS
– Millimetre-wave Airborne Receiver for Spectroscopic CHaracterisation of Atmospheric Limb-Sounding
– a new airborne mm-wave limb sounder for the UTLS
– built under ESA contract by a consortium led by Rutherford Appleton Laboratory in the UK
• Contents
– Background, scientific rationale
– Instrument description
– Current status
– Future Plans
Marschals Objectives
• Demonstrate the capability of the mm-wave limb-sounding technique, to be employed by MASTER, to sound H2O, O3 and CO in the UT/LS region
– MASTER: proposed spaceborne limb sounder to measure thermal emission spectra at mm and sub-mm wavelengths
– mm-wave region: where extinction by aerosol and polar stratospheric clouds is negligible and extinction by cirrus clouds is low
• Participate in field campaigns in its own right (strat-trop exchange, radiative forcing, UT&LS chemistry)
MARSCHALSon Geophysica
The Marschals Instrument
• To simulate UTLS capabilities of MASTER as closely as possible, deployment on:– Geophysica near 20 km (primary carrier)
• Potential to retrieve horizontal and vertical structure in UTLS H2O, O3 and CO fields
– High-altitude balloon (secondary carrier) near 35 km• Capability for profile retrieval up to the mid-
stratosphere
Instrument Details
• MARSCHALS:– High efficiency antenna (22 cm) to make precise
elevation scans though the atmosphere– Heterodyne receiver concept– SSB receivers – 200 MHz spectral resolution (cf 50 MHz for MASTER)– Sideways viewing (cf rearwards for MASTER)
– CCD array coupled to standard lens and broad-band filter (835-875nm)
– Records near-IR sunlight scattered in limb direction
• to identify cloud-free measurements for initial data analysis
• to indicate cloud conditions of each mm-wave measurement for analysis and interpretation, e.g.
– confirm mm-wave insensitivity to cloud
– relate mm-wave retrieved trace gas abundances to cloud
SAGE-II Cloud Climatology
Cirrus Extinction vs Wavelength
Retrieval simulations - PrecisionBand B O3
MARSCHALS (aircraft)
MASTER
MARSCHALS (balloon)
% Error % Error
Alt
/ km
Alt
/ km
Band C H2O
% Error
Alt
/ km
Band D CO
Structural Test Model, May 2002
Structural Test Model, May 2002
Jan 2004
Current Status
• Instrument ~ 95% complete• Two RAL receivers, bands C and D, each with 12 GHz of
instantaneous bandwidth (@ 200MHz resolution)• Need to pass EMC test before flight• Characterisation of the full instrument is underway• L1 software ready
Deployment plans
• Funding for initial test flight and campaigns from EU APE-INFRA and ESA MALSAC
• Geophysica test flight March cancelled– Alternatives being investigated