Exploiting Formation Flying for Earth Science: P-band Distributed Synthetic Aperture Radar

1) each satellite works with a reduced PRF given by . After the processing the AAR is the same but the RAR increases significantly (see Figure 1, left side); 2) the improvement in the final RAR can be exploited for reducing the antenna size in the along range dimension at the expenses of antenna gain. This can be balanced by increasing the averaged transmitted power by exploiting the larger pulse interval allowed by the reduced PRF. In this way the NESN can be kept low or even equal to the original system (see Figure 1, right side); 3) the increasing of averaged transmitted power directly causes an increase of power demand for each satellite, if multi-monostatic configuration is used. In this operative mode each antenna is transmitting/receiving its own signal (see Figure 2, left side), so that tight real time control of the formation is not necessary. In fact, azimuth sampling accuracy is connected to the choice of transmission instants, so accurate real time knowledge (not control) of relative position is only required. In the multistatic configuration (see Figure 2, right side) the different apertures receive the same signal transmitted by one satellite, so that the uniformity in azimuth sampling is achieved by real time relative position control among the formation. If the role of transmitting source is switched among the satellites along the orbit the total averaged power demand of the system can be distributed among the components of the formation. The final result is that, by using standard techniques of flyformation control, it is possible to reduce significantly the amount of averaged power for each satellite, allowing an implementation on micro or nano platforms; 4) finally, the overall measurement scenario can be completed by adding one mother spacecraft working as the transmitter and forcing the linear formation to work only as receiving stations. This, from one side, allow a further reduction of weight and size of each satellite and also permits to maintain the same overall performance with a lower number of receiving system. On the other side, by considering a cartwheel configuration for the mother satellite, it is possible to open the door to several interferometric application (along and across-track) for a large number of application including ice sounding; 5) for the mother satellite, it is possible to open the door to several interferometric application (along and across-track) for a large number of application including ice sounding Exploiting Formation Flying for Earth Science: P-band Distributed Synthetic Aperture Radar