A radar for the exploration of exstrasolar planets

A radar for detecting and mapping terrestrial-type planets around distant suns is described. Using technology not greatly beyond that presently available, this radar will detect and image terrestrial planets up to a few tens of light years away with a mapping resolution of a few tens of kilometers. The radar is bistatic with the transmit antenna ensemble in solar orbit inside Mercury´s orbit and the receive antenna ensemble in an orbit beyond Jupiter. The net motion of the phase center of the two ensembles of antennas generates a circular synthetic array with a diameter of about 10⁹km. Such an array will have a synthetic-array angular resolution of 2.5 × 10^-13rad at a carrier frequency of 600 MHz, corresponding to a resolution of 2.5 km per light year of range.