Year: 2014
Type: conference-paper
Abstract: The Earth’s lower thermosphere is an important interface region between the neutral atmosphere and the “space weather” environment. The NSF-sponsored Optical Profiling of the Atmospheric Limb (OPAL) mission is designed to map global thermospheric temperature variability at mid- and low-latitudes over the critical “thermospheric gap” region (~100-140 km altitude) where prior data are sparse. OPAL will profile the thermosphere temperature from 90 to 140 km altitude by observing the daytime O2 A-band emission. OPAL measures the thermosphere neutral temperature by spectroscopic analysis of molecular oxygen Aband emission (758 – 768 nm). This paper presents the OPAL mission science, instrument design, and measurement capabilities. OPAL is expected to launch in late 2016 with a mission duration > 9 months. The OPAL instrument is a grating-based imaging spectrometer with refractive optics and a high-efficiency volume holographic grating (VHG). The scene is sampled by 7 parallel slits that form non-overlapping spectral profiles at the focal plane with resolution of 0.5 nm (spectral), 1.5 km (limb profiling), and 60 km (horizontal sampling). A CCD camera at the instrument focal plane delivers low noise and high sensitivity. The instrument is designed to strongly reject stray light from daylight regions of the earth.
Authors: Alan Marchant, Mike Taylor, Charles Swenson, L. Scherliess
Institution: Utah State University
Language: English
Subfield: Space and Planetary Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W35504098