Abstract: A method of operating synthetic aperture radar in a low PRF mode, comprising generating a stream of radar pulses, imposing onto said stream a predetermined modulation of the Pulse Repetition Frequency (PRF), directing said stream to a target area, and processing received pulses, comprising separating the received pulses as a sequence of sets, and superposing received radar pulses of said sets, whereby to enhance the central received lobe and to attenuate side lobes.

Abstract: A method of operating synthetic aperture radar in a low PRF mode, comprising generating a stream of radar pulses, imposing onto said stream a predetermined modulation of the Pulse Repetition Frequency (PRF), directing said stream to a target area, and processing received pulses, comprising separating the received pulses as a sequence of sets, and superposing received radar pulses of said sets, whereby to enhance the central received lobe and to attenuate side lobes.

Abstract: A transmit-receive module has a battery energy store with associated circuitry for generating power (RF power) over periods ranging, as desired, from periods as short as small fractions of one second to continuous emissions over prolonged periods. The arrangement bears a definite cost advantage over known arrangements and retains utility for various applications, radar and space-based applications for example.

Abstract: An imaging apparatus has transmitter illuminating a selected surface with a radar beam footprint, and processor for profiling/processing the radar returns so as to derive attitude information in real time about a number of predefined axes associated with the radar which depends upon the relative dispositions of the radar, the selected surface and upon the radar beam footprint characteristics. A plurality of transmit beams image the surface and the processing arrangement has the capability of determining roll, pitch and/or yaw pointing data associated with the radar, such pointing data being determined by derivation of the attitude information and by selective input of terrain elevation data so as to take account of variations in the radar viewing geometry with terrain elevation. This provides a low cost advantage over known radar designs, and retains utility for many applications, for example spaceborne and airborne applications.

Abstract: A spacecraft platform essentially having two or more panels hinged at the base and contained for launch in a fairing. The panels are hinged and latched in an open deployment and bear, for example, a SAR antenna or an interferometer. The rear faces of the panels are provided with stiffening ribs, webs and struts and carry elements of the payload module and service module which are normally separate structures on a conventional satellite.