Simulating the CIPS Instrument

We present preliminary results of simulating the view of the Cloud Imaging and Particle Size (CIPS) instrument onboard the Aeronomy of Ice in the Mesosphere (AIM) satellite.  The CIPS instrument is a four-camera imager that captures backscattered light in the ultraviolet range.  Its primary objective, as one of the three instruments on the AIM satellite, is to capture images of Polar Mesospheric Clouds (PMCs) which form near the summer mesopause.  These images are captured every 43 seconds over the summer pole, such that each location in the field-of-view (FOV) may be seen from as many as seven different scattering angles.  This allows direct measurement of the cloud scattering phase function. From the phase function, the cloud albedo, ice water content, and particle radius can be calculated.  However, the AIM satellite’s orbit has changed significantly over the lifetime of the mission.  The CIPS instrument will soon be unable to capture images of the Earth every 43 seconds.  Instead, images will be captured all along the orbital track at a much longer time interval.  It is important to simulate the CIPS instrument to better understand what data and products can be returned with this new orbit.  We do this by first projecting the instrument’s FOV onto the planet at a given latitude, longitude, and altitude.  We then add a simulated cloud field designed to match the Level 1a data product.  Our initial simulations indicate that we can very closely match the FOV of existing images and the data products closely match those derived from the cloud field.