Washington State University


  • George Mount
  • Elena Spinei
  • Tom Jobson
  • Matt Erickson
  • Will Wallace
  • Jacob McCoskey



MFDOAS instrument is designed to measure UV/VIS direct sun irradiance and scattered sky radiance for atmospheric trace gas retrieval. Spectra are recorded by the spectrometer/CCD system with a spectral resolution of 0.83nm (7.8 pixels/FWHM) from 281 - 498 nm. Instrumental fields of view for scattered and direct sun light are 1o x 0.025o, and 1o respectively. Direct sun light is guided into a spectralon integrating sphere where multiple scattering within the sphere assures uniform illumination of the spectrometer optics, thus minimizing effects of pointing errors. Scattered sky measurements can be taken at any azimuth and elevation angles allowing for multi-axis and zenith sky observations. The instrument exhibits excellent signal to noise properties and sensitivity. A narrow band UV filter is used to (nearly) eliminate the effects of unwanted stray (scattered) light in the spectrometer system at shorter wavelengths as for HCHO measurements. Average integration time in direct sun (DS) and zenith sky (ZS) modes are less than a second. The instrument has been used extensively in the field, including field campaigns at NASA Goddard Space Flight Center, NASA JPL, Pacific Northwest National Laboratory, Univ. of Alabama, etc.


The goal of this collaborative project is to determine the area-averaged HCHO fluxes in the Texas City and Mt. Belvieu areas from industrial sources by using two MAX-DOAS instruments, one from UCLA, the other from Washington State University, which use scattered sunlight as a light source to measure the slant path-integrated concentration of HCHO. One instrument will measure upwind column densities while the other will measure downwind column densities as a function of time. A wind profiler will measure wind velocities.

wsu/home.txt · Last modified: 2009/04/02 08:01 by tihuang
Back to top
University of Houston |  Earth & Atmospheric Sciences |  IMAQS |  H-NET |  TLC2 |  HARC |  TCEQ |