SOIR data workshop SOIR Exercises A.C. Vandaele, R. Drummond, A. Mahieux, S. Robert, V. Wilquet SOIR Belgian Institute for Space Aeronomy (IASB-BIRA)

SOIR data workshop Overview  Data overview tool (Orbit_Order)  Plot Occultation tool (PlotOccultationPDS_0)  Synthetic spectrum construction

SOIR data workshop SOIR tools (1)  Exercise 1: Find two orbits, one close to the equator and one close to the pole, for which CO has been measured simultaneously in transition band  (orders 141, 142, 143) – low altitude  (orders 148, 149, 150) – mid altitude  (orders 164, 165, 166) – high altitude  Exercise 2: Find orbits for which the HDO/H 2 O ratio can be calculated, i.e. H 2 O and HDO has been measured simultaneously. Check if the latitude dependence can be studied.  HDO: orders 119 to 124  H 2 O: orders 167 to 172 Check if the altitude range overlap using the PlotOccultationPDS_0 tool.

SOIR data workshop SOIR tools (2)  Exercise 3: Find orbits for which the CO volume mixing ratio can be calculated simultaneously with the HCl volume mixing ratio, and who were measured between 60 and 80°N.  CO: orders 187 to 192  HCl: orders 127 to 132  CO 2 : orders 141 to 143 and 148 to 151 Check if the altitude range where the species absorb in each orbit overlap using the PlotOccultationPDS_0 tool. Check if the detector temperature was below 88 K.

SOIR data workshop Synthetic spectra construction (1)  Exercise 4: The CO 2 main isotopologue vibrational transition band absorbs in diffraction order 149. Using the precalculated absorption cross section (ACS) from file (under Matlab) or (CSV file), reconstruct the synthetic spectrum using 5 adjacent orders (147 to 152).

SOIR data workshop Synthetic spectra construction (2)  4.1. Determine the wavenumber range in each order  4.2. Calculate the ACS in each order  4.3. Multiply by the blaze function in each order  4.4. Multiply by the AOTF function in each order  4.5. Convolve the spectrum  4.6. Sum the orders  4.7. Make the same operation with the denominator (ACS = 1)  4.8. Perform the division  Data:  n CO2 = molec/cm 3  T = 200 K  p = 0.01 bar  Path length = 100 km  Instrument resolution = 0.15 cm -1  Pixel to wavenumber relation

SOIR data workshop Thank you for your attention