1 / 21

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

virginia-gallagher
Download Presentation

Victoria Jay, Brian Kerridge, Jolyon Reburn, Richard Siddans,

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MARSCHALS: a new airborne millimetre-wave limb-sounder for the UTLSCOST 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

  2. 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

  3. 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)

  4. MARSCHALSon Geophysica

  5. 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

  6. 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)

  7. Instrument Details • Bands: • B: 294 - 305 GHz O3, pointing • C: 316.5 – 325.5 GHz H2O • D: 342.8 – 348.8 GHz CO • Modular design: more bands can be added • Baseline scan sequence: • -2 to 21 km in 1 km steps

  8. MASTER Bands

  9. OCM • Optical Cloud Monitor: • 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

  10. SAGE-II Cloud Climatology

  11. Cirrus Extinction vs Wavelength

  12. MASTER MARSCHALS (balloon) MARSCHALS (aircraft) Retrieval simulations - Precision Band B O3 Band C H2O Alt / km Alt / km Band D CO % Error % Error Alt / km % Error

  13. Structural Test Model, May 2002

  14. Structural Test Model, May 2002

  15. Jan 2004

  16. 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

  17. Deployment plans • Funding for initial test flight and campaigns from EU APE-INFRA and ESA MALSAC • Geophysica test flight March cancelled • Alternatives being investigated • Rescheduled Geophysica flight (May/June earliest) • Jungfraujoch ? • Scientific flights in future Geophysica campaigns • Alongside MIPAS-STR and SAFIRE-A

  18. Summary • MARSCHALS • New mm-wave airborne limb sounder • O3, H2O, CO and other trace gases in the UTLS • First flight soon • See poster: Tomographic limb-sounding of the Upper Troposphere and Lower Stratosphere • 2-D retrieval simulations for MASTER

  19. MARSCHALS L1 ATB ReviewBaseline Scan Sequence • Scan -2km to 21km tangent height, integrating for 0.25s at each observation state. • At each tangent height • 7 observations, 2 RF switches: 50ms each • Total time per tangent height: 2.2s • Total time for sequence: 52.8s (antenna motion during a cal.load view). • In addition, limb scan • Starts hot/cold observation • Ends with cycle through all bands at max. elevation (above horizontal).

More Related