Imaging apparatus and method

A method of imaging a surface from a platform moving relative to the surface, the method comprising the steps of:

• transmitting radiation to the surface;
• receiving the radiation, after it has been scattered from the surface, along a predetermined receive path;
• and
• processing signals representative of the received radiation to provide radar attitude information, the attitude information being representative of the pointing of the platform resolved into a number of axial components and wherein the attitude information is derived in dependence upon a determination of a range characteristic relative to the surface and upon a determination of a Doppler frequency distribution associated with the scattered radiation, further comprising correlating the received data associated with the scattered radiation with predetermined radar antenna pattern data, deriving peak position data representative of the radar antenna boresight direction, transforming said peak position data into slant range and Doppler frequency space, and determining the attitude information in dependence upon such various operations.

In a radar imaging apparatus comprising a moving platform mounting a radar, the radar including transmitting means, the transmitting means providing a plurality of transmit beams, receiving means, and signal processing means, a method of imaging a surface comprising:

• receiving transmitted radar signals scattered from the surface, and processing the signals to determine (i) a range characteristic of apparatus relative to the surface, and (ii) a Doppler frequency distribution characteristic of the received signals;
• determining from at least one of said range characteristic and said Doppler frequency distribution characteristic a roll attitude of the apparatus about a roll axis, a pitch attitude of the apparatus about a pitch axis, and a yaw attitude of the apparatus about a yaw axis;
• and
• adjusting at least said transmitting means so as to compensate for said roll attitude, said pitch attitude and said yaw attitude in said imaging.

A radar imaging apparatus comprising a moving platform mounting a radar, the radar including transmitting means for transmitting a plurality of transmit beams, receiving means for receiving transmitted radar signals scattered from the surface, and signal processing means for processing received signals, the processing means including:

• means to determine a range characteristic of apparatus relative to the surface, and means to determine a Doppler frequency distribution characteristic of the received signals;
• means for determining from at least one of said range characteristic and said Doppler frequency distribution characteristic, a roll attitude of the apparatus about a roll axis, a pitch attitude of the apparatus about a pitch axis, and a yaw attitude of the apparatus about a yaw axis;
• and
• means for adjusting at least said transmitting means so as to compensate for said roll attitude, said pitch attitude, and said yaw attitude in said imaging.