Feasibility Study of a High‐Resolution Shallow Surface Penetration Radar for Space Application

We modified and justified the radar equation for ground penetration by including the backscattering effect. We propose a strawman system on an orbiter 50 km above the surface based on lunar conditions. The Tightly coupled dipole arrays antenna substantially reduces the size and mass and consists of an array with 8 x 8 cells on a light weight plate that is 1.6(2)-m(2) wide with cells 0.25-m high providing increased directionality and beam-steering capability. The system includes 8 transmitters and 16 receivers that are able to measure wave polarization so that it is sensitive to subsurface water/ice. The system is controlled by central computers with transceivers all programmable providing more functionalities and flexibilities enabling systems of an even larger number of transceivers. It uses the synthetic aperture radar method to enhance the spatial resolution along the orbit track and has phase steering capability to increase the resolution in the cross-track direction. The total transmitted power is 160 W. The radar is able to operate in three modes: a fine-resolution mode that provides the full Multiple-Input Multiple-Output ultrawideband (MIMO UWB) capability with vertical range resolution up to 0.2 m, a deep penetration mode that is able to penetrate 100 m for high attenuation targets or over few kilometers for low attenuation targets, and a survey mode that provides overall characterization of the planet economically. This system can provide internal properties and structures of a target and detailed information about most useful resources such as ice, water, minerals, and shelter caves, for human space exploration on the Moon, Mars, and asteroids.