Correcting NOAA-AVHRR Orbital Drift: a Simple and Automatic Methodology

NOAA (National Oceanic and Atmosphere Administration) AVHRR (Advanced Very High Resolution Radiometer) data scientific use is hindered by the orbital drift each platform has suffered, which prevents multitemporal analyses. The study presented here provides a new way to correct the data from this orbital drift, using additional information on the data acquisition, such as solar zenithal angle and acquisition day information. This information is used to estimate at each date and for each pixel a theoretical solar zenithal angle, which difference to the actual one is fitted against each channel data anomaly. This fit is then used to calculate a correcting factor which is applied to the whole time series for each channel data. This procedure has been applied to data provided by the GIMMS (Global Imaging Modeling and Mapping Studies) group, namely the African continent from the end of 2000 to the end of 2004, corresponding to NOAA-16 satellite.