About this exercise type...

In the dayside section of its orbit the ERS-2 carrying GOME satellite is travelling north to south. Its ground speed is approximately _ km/s. The instantaneous field of view of the spectrometer is _ x 40 km. The maximum scan width at ground level is _ km.

The full east to west scan of the mirror through this width is completed in _ s. During this scan three successive spectral measurements are performed. The integration time of a single spectral measurement is _ s, which is the result of co-adding _ individual measurements of _ s. The ground area of the scan is therefore sampled in _ pixels, each having an area of _ x 40 km.

The scan mirror flyback takes _ s and is used to carry out an additional spectral measurement. The integration time of this pixel is _ s and its ground area _ x 40 km.

The spectral measurements taken in channel 1a, UV 240–283 nm, are an exception to this sequence. _ seconds are required to integrate the measurement in this wavelength range, corresponding to the area covered by _ standard pixels.