###### Abstract  
Passive radar is a technology that has huge potential for airspace monitoring, taking advantage of existing transmissions. However, to predict whether particular targets can be measured in a particular scenario, it is necessary to be able to model the received signal. In this paper, we present the results of a campaign in which a Pilatus PC-12 single-engine aircraft was measured with a passive radar system relying on DVB-T transmission from a single transmitter. We then present our work to simulate the bistatic RCS of the aircraft along its flight track, using both the method of moments and the shooting and bouncing ray solvers, assess the uncertainty in the simulations, and compare against the measurements. We find that our simulated RCS values are useful in predicting whether or not detection occurs. However, we see poor agreement between simulated and measured RCS values where measurements are available, which we attribute primarily to the difficulties in extracting RCS measurements from the data and to unmodeled transmission and received path effects. p 2022  
measured RCS of specific targets was performed, obtaining a good match. In the pioneer work [16], the issue of calculating the bistatic RCS from monostatic measurements was addressed, along with its limitations. In [17], the authors focused on the main sources of computation and measurement uncertainties, while [18] focused on the mutual information content between monostatic and bistatic measurements. [PERSON] [19] addressed the problem of simulating the RCS of a specific target over a wide bandwidth, concluding that this is a difficult task. In this paper, we focus on the validation of passive-radar-based, bistatic RCS measurements for a specific target. In particular, in June 2015, armasuisse W+T and Fraunhofer FHR conducted a joint measurement campaign exploiting a DVB-T-based passive radar system and a cooperative target, namely a Pilatus PC-12 aircraft. The target response obtained after conventional passive radar processing [20; 21] was extracted for several tens of seconds along the flow trajectory. Thanks to an inertial measurement unit (IMU) mounted onboard the target, both target trajectory and target attitude were recorded. The aforementioned target response was then converted into an estimate of the target bistatic RCS by inverting the bistatic radar equation. In doing so, special attention was devoted to compensating for potential sources of error in the derivation of the measured target RCS. Among these, the control of the measurement noise floor at a constant level over time was the most challenging. To validate the bistatic RCS measurements, corresponding sets of simulated bistatic RCS values were calculated for the same trajectory and attitude by using both methods of moments (MoM) and enhanced shooting and boucing ray (SBR+) solvers, applied to a 3D CAD model of the Pilatus PC-12. On the simulation side, an error analysis was conducted to account for RCS variations over coherent integration time and over signal frequency bandwidth, as well as the potential errors introduced by uncertainties in the IMU measurements and possible assumptions about propagation through the atmosphere. The key goal of this work is to develop an understanding of the capabilities and limitations of electromagnetic bistatic RCS simulations when applied to a real passive radar measurement, and in so doing, gain some insight into the necessary steps. The intention is that such insights can later be applied to simulations of other aircraft, including in cases where a co-operative target is unavailable for measurement and therefore for which simulation is particularly valuable. This could also later be applied to stealth aircraft. The remainder of this manuscript is organized as follows. In Section 2, we introduce the measurement campaign jointly conducted by armasuisse W+T and Fraunhofer FHR in Switzerland, also describing the experimental passive radar system and the particular scenario configuration.