SOLAR OCCULTATION FOR ICE EXPERIMENT
The Solar Occultation For Ice Experiment (SOFIE)
began science observations on 14 May 2007. SOFIE performs
solar occultation measurements in 16 spectral bands that are
used to retrieve vertical profiles of temperature, O3,
H2O, CO2, CH4, NO, and PMC
extinction at 11 wavelengths including band 2 which will be
available in a limited data set in future releases. Each day
SOFIE provides 15 sunset measurements at latitudes ranging
from 65° - 85°S (depending on time of year) and 15
sunrise measurements at latitudes from 65° - 85°N.
SOFIE images the sun with a 2D detector array to obtain pointing
knowledge of the FOV position relative to the sun center to
within ±0.1 arc second through image edge analysis.
As a result, SOFIE obtains an unprecedented fidelity of observation
altitude and angle. This allows the inference of refraction
angle profiles, from solar extent measurements, that are used
to retrieve temperature from ~55km down into the upper troposphere,
independent of transmission models. SOFIE is the first occultation
sensor to successfully use this technique to such high altitudes.
- The Space Dynamics Laboratory at Utah State
University (SDL) designed, fabricated, tested, and integrated
the SOFIE instrument.
- GATS Inc. defined the SOFIE measurement system
and worked with SDL throughout design, fabrication, and
testing phases. GATS conducts SOFIE flight operations and
retrievals of physical results from flight data.
- SOFIE will use solar occultation to measure
the following atmospheric constituents:
- Carbon Dioxide
- Nitric Oxide
- SABER Heritage
- Aperture cover uses same actuators
- Similar telescope design (M1 & M2)
- Similar radiator design
- Similar tuning fork chopper
- Similar electronics
- WRE Heritage