Purpose of the flight and payload description
The LPMA instrument (Limb Profile Monitor of the Atmosphere) is a high spectral resolution Fourier transform spectrometer operating in absorption against the sun. The objective is to record limb atmospheric spectra in selected intervals from the thermal infrared to the near-infrared.
The instrument is composed by a commercial BOMEM DA2 spectrometer customized for balloon operations. A specially designed two detectors output optics enables to cover simultaneously two spectral regions making it possible to sample simultaneously the two interferograms detected during the same scan of the moving mirror and allowing to collect information on atmospheric species absorbing in widely different spectral regions.
In order to reach a good signal to noise ratio spectra performance, the interferometer must be feeded with a stable solar beam exactly aligned along the optical axis of the instrument. To be able to do this, two sub-systems of the gondola are needed:
- a primary pointing system initially developed by the Observatory of Geneva for astronomical payloads, controling the azimuth of the gondola and maintaining the sun in the field of view of the instrument even during ascent in the dense layers of the upper troposphere or lower stratosphere where this is a rather difficult achievement.
- a suntracker (also known as a heliostat) developed in cooperation with the Institut d'Electronique el de Micro-electronique du Nord performing the fine pointing of the acquisition mirror through 2 axes servo-controlled gimbal compensating for the residual motions of the payload and maintaining a jitter of the solar beam direction at the input of the interferometer of less than 1 arc min.
In addition it is possible to accomodate on the gondola another instrument of the class 30-50 kg wich can benefit from their good pointing capabilities.
Details of the balloon flight
Balloon launched on: 8/18/2002
Launch site: European Space Range, Kiruna, Sweden
Balloon launched by: Centre National d'Etudes Spatiales (CNES)
Balloon manufacturer/size/composition: Zero Pressure Balloon
End of flight (L for landing time, W for last contact, otherwise termination time): 8/18/2002
Landing site: 40 km W of Jokkmokk, Sweden
- LPMA project website Laboratoire de Physique Moléculaire pour l'Atmosphère et l'Astrophysique (via Archive.Org)
- Balloon-borne limb profiling of UV/vis skylight radiances, O3, NO2 and BrO: technical set-up and validation of the method Atmos. Chem. Phys., 5, 1409-1422, 2005
- ENVISAT Validation Results Obtained with LPMA and IASI-Balloon FTIR 2nd Workshop on the Atmospheric Chemistry Validation of ENVISAT, 2004
- List of balloons launched from ESRANGE SSC Space website (via Archive.Org)
- Overview of SCIAMACHY validation: 2002-2004 Atmos. Chem. Phys., 6, 127-148, 2006
- The Validation of the Envisat Chemistry Instruments by Use of Stratospheric Balloons and Aircraft ENVISAT Validation Workshop (ESA SP-531). 9-13 December, Frascati, Italy
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