The Copernicus imaging microwave radiometer (CIMR) is a high priority Copernicus mission for evolving the Copernicus system

2019-02-21T14:47:48Z (GMT) by Rasmus Tonboe

The figure is showing the simulated high resolution sea ice concentration from the envisioned CIMR sensor. The sea ice concentration is computed using an imaging simulator.


The reference sea ice concentration is derived from the brightness of cloud-free MODIS scenes at 250 m x 250 m pixel size. The MODIS pixel brightness across the image may vary slightly as a function of solar angle and albedo (snow type and sea ice type), leading to uncertainties in the derived ice concentration. However, here it is just used as the reference and it does in fact provide a realistic spatial distribution of ice at the right scale for input to the model and as a reference for comparison. Each of these 250 m x 250 m ice concentration pixels is assigned a microwave brightness temperature using standard tie points for ice and water and linear mixing between 0 and 100 % for the range of MODIS pixel brightness values.


For each 250 m x 250 m brightness temperature pixel 2D elliptical Gaussian-shaped antenna patterns are folded with the high resolution reference to simulate brightness temperatures at 19v and 19h and 37v and 37h as it would be measured on the satellite with SMMR, SSM/I, AMSR 2 and the proposed CIMR. The simulations of brightness temperatures are used as input to the Bristol algorithm using the standard tie points also used in the reference. The model and the procedure is described in Tonboe et al., (2016).


Tonboe, R. T., Eastwood, S., Lavergne, T., Sørensen, A. M., Rathmann, N., Dybkjær, G., Pedersen, L. T., Høyer, J. L., and Kern, S.: The EUMETSAT sea ice concentration climate data record, The Cryosphere, 10, 2275-2290, https://doi.org/10.5194/tc-10-2275-2016, 2016.