| Popis: |
The perception that some of man's activities in the Earth's atmosphere might be inimical to his well being (1, 2) has led to the need to thoroughly understand the chemical and physical processes controlling the Earth's stratosphere. At present, there is a considerable effort being made to do this by a combination of theoretical modeling efforts (3, 4) and accompanying experimental work to obtain stratospheric data using devices on the ground (2, 5), aboard aircraft (6), on rocketsondes (7), on parachutesondes released from balloons (8), on high altitude balloons (9), and aboard spacecraft (10). The remotesensing devices aboard spacecraft are capable of monitoring the stratosphere almost globally and for long periods of time. These attributes are not economically feasible for devices on any other platform. It is therefore to be expected that in the future, spacecraft-borne instruments will become increasingly important in monitoring the stratosphere. Spacecraft-borne instruments, for the most part, detect atmospheric emission or atmospheric solar absorption (during solar occultation) at infrared wavelengths where many of the important species in the stratosphere exhibit vibrational-rotational spectra. The Laser Heterodyne Spectrometer (LHS) is one of the instruments under development by the NASA for possible spacecraft use in monitoring the stratosphere. This instrument owes its uniqueness to its ultrahigh spectral resolution and its shot-noise limited sensitivity. |
