The LPMA (limb profile monitor of the atmosphere) instrument is a Fourier transform infrared (FTIR) spectrometer of the BOMEM DA2.01 type. It is used to perform balloon-borne remote sensing measurements of stratospheric (and in some case tropospheric) trace species. As an instrument working in absorption against the sun it is accommodated on a stratospheric gondola with pointing capabilities. The primary pointing system is used to put (and to maintain) the sun into the field of view of a sun-tracker (heliostat) acting as a fine pointing system to compensate for the residual motions of the gondola. This configuration allows to feed in a stable manner the infrared solar radiation along the optical axis of the spectrometer (through a germanium window used to reject the unused visible-UV flux). The complete system i.e. gondola, pointing-system, heliostat, FTIR spectrometer, on board processing and recording as well as telemetry unit has flown several times (from Aire-sur- l'Adour in France, from ESRANGE in Sweden and from Leon in Spain) under stratospheric balloons operated by CNES. A description of the various subsystems will be presented together with samples of representative ground tests and in flight measurements.

Date Published: 7 June 1996
PDF: 8 pages
Proc. SPIE 2739, Acquisition, Tracking, and Pointing X, (7 June 1996);

Published in SPIE Proceedings Vol. 2739:
Acquisition, Tracking, and Pointing X
Michael K. Masten; Larry A. Stockum, Editor(s)