GOME-2 overview
The Global Ozone Monitoring Experiment (GOME-2) is a nadir-viewing spectrometer that observes solar radiation transmitted or scattered from the Earth atmosphere or from its surface.
The instrument is set-up as a double spectrometer. This meets the requirement for:
- spectral coverage from in the ultraviolet and visible spectral region (240 to 790 nm)
- good spectral resolution (0.2 to 0.4 nm)
- proper straylight performance in its channels
GOME-2 is split into the functional units:
- double Spectrometer
- Polarisation unit (PU) with s- and p-channel
- Calibration unit for in-orbit calibration
- Focal Plane Assemblies with 1024 detector array and coolers
- Scan unit for across-track Earth scanning and view to calibration sources
- Control and Data Handling Unit
For detailed specifications, see the performance table.
GOME-2 measures
- backscattered Earth radiance and Sun irradiance using its Ultra-violet, visible and near infrared double spectrometer
- s- and p- polarized light with medium resolution
- total column of ozone and nitrogen dioxide and other minor trace gases (like Sulphur dioxide (SO2), bromine oxide (BrO), chlorine dioxide (OClO) and formaldehyde (CH2O)
- ozone profiles of our atmosphere
GOME-2 has a spatial resolution of 40 x 40 km² for a 960 km swath and 40 x 5 km² for the polarisation measurements. The GOME-2 instantaneous field of view at about 40 km x 4 km, is equivalent to 2.8° x 0.29°. The instrument uses a scanning mirror that scans across the satellite track. With a 960 km scan, global coverage can be achieved within three days.
On-ground calibration is required to achieve radiometric calibration and to account for the effects of straylight. Radiometric results are derived through ground processing of measured radiance and irradiance.
