Radar system and method for a synthetic aperture radar

The radar system according to 1, wherein the radar system is arranged to operate in a sub-band within the frequency range 20-500 MHz

• and/or
• wherein the wide bandwidth B of the frequency band is arranged to cover 1.6 octaves corresponding to the highest frequency in the frequency band being three times the lowest frequency in the frequency band.

A method for arranging a radar system for a synthetic aperture radar comprising an arrangement comprising at least one transmitter, two receivers, two antennas and a signal processor located on a platform moving over ground and transmitting a known signal shape and receiving signals reflected from the ground, the received signals being used to produce a synthetic aperture radar image of the ground, the synthetic aperture radar image comprising a number of resolution cells, and the radar system operating in a frequency band with a center frequency and with a wide bandwidth of at least one octave, wherein the radar system comprises a first and a second antenna having a length of less than half the wavelength of the center frequency and further by arranging:

• a radar system transfer function to be flat over the frequency band by equalizing and pulse compressing the received signals by the signal processing means and
• one-sided beam forming with wideband antenna gain, by utilizing a first receiver and a second receiver channel where the first receiver channel receives a signal from the first antenna and the second receiver channel receives a signal from the second antenna and further by matching antenna separation with a phase difference of 2α degrees between the transmit signals fed into each antenna, 2α being in the vicinity of 90 degrees.