Mini-Dual Earth Sensor

The MiDES (Mini Dual Earth Sensor) is specifically designed to provide horizon position in both Pitch and Roll for Earth orbiting unmanned LEO satellites. The MiDES derives its information through the use of two pairs of 16 element pyroelectric detectors positioned 90 degrees apart, combining to provide 32 pixels that view the horizon Each 16 element array is spatially separated into two 8 element staggered columns shown below to provide for sun/moon rejection and for radiance compensation. Covering a FOV of 11 degrees, the pixels detect the temperature difference between the reference chopper, Earth and Space through measurement of the CO2 band thermal gradient. An algorithm calculates the position of the horizon based on the voltages obtained from the pixels that subtend the horizon. Earth and Space looking pixels are used to reduce radiance errors.