Improved Method of PRF Selection in Spaceborne SAR Robust to Altitude Changes and with the Ability to Stabilize the Transmission Power

In this paper, an improved pulse repetition frequency selection method for the spaceborne synthetic aperture radar is proposed, where the design considerations of the other system parameters including antenna dimensions, azimuth and range resolution, pulse width, swath width, incidence angle / look angle, orbital altitude and local radius of the earth are taken into account. In the proposed method, in addition to the ability to change the incidence angle, the effects of changes in the orbital altitude and the local radius of the earth are also considered in the design. Also, in this method, in order to stabilize the transmitted power, the design for constant duty cycle mode can be done accurately, which can be very important in a practical system. Also, by using fixed duty cycle in the proposed method, the range of available pulse repetition frequency values and incidence/look angles will significantly be increased. Finally, for a typical system, the results of computer simulation and design using the proposed method for the both constant duty cycle and constant pulse width modes are given, which confirms the above capabilities.