**5.1 Models and tool supporting SOSE CONOPS Assessment**

The MS&A models and tool implemented in Matlab13 for SOSE CONOPS assessment presented in this section are derived from [10]. The models and Matlab tool focus on space SOSE [9, 20] in the presence of friendly RFI threats. The current Matlab models and tools include public open source databases for military, commercial and civilian satellites and ground systems. They can be used to evaluate key SOSE CONOPS performance metrics, including (i) Communication LM and communication link availability in terms of network score, and (ii) the three key resiliency metrics for measuring spectrum resiliency against RFI threats. The three key resiliency metrics are (a) Resilience Assessment Index against RFI (RAI-RFI), which is a measure of "Reconstitution" metric calculating the probability of a ground/satellite

<sup>13</sup> The Matlab tools were developed jointly by The Aerospace team and CSUF graduate student team. CSUF team includes Tom Free, Scott Digiambattista, Nicole Hemming-Schroeder, Catherine Osborne, Lauren Benson, Jordan Golemo, and Maria Heinze under the Industry Collaboration program between CSUF and The Aerospace Corporation. The CSUF program director is Prof. Charles Lee.

system being disrupted by RFI and its ability to reduce RFI by re-routing the desired signal to avoid RFI threats, (b) Spectrum Resiliency Assessment Index against RFI (SRAI-RFI), which is a measure of "Avoidance-Robustness-and-Reconstitution" metric for evaluation of the ability of a system that can access the spectrum and be able to response to a disruptive event - SRAI-RFI is a metric calculating the probability that a system can access to its allocated RF frequency band in the presence of RFI threats, and (c) Resilient Capacity against RFI (RC-RFI), which is a measure of "Avoidance, Robustness, Reconstitution, and Recovery." The RAI-RFI Model generates a "Heat-Map" to show areas impacted by RFI threats, SRAI-RFI Model generates a "Heat-Map" to show the likelihood that a communication system can access to the allocated frequency-band in the presence of RFI events, and RC-RFI Model generates SOSE communication LM and link availability for the "areas identified by RAI-RFI and SRAI-RFI" models. **Figure 12** shows the Matlab Graphic User Interface (GUI) of the Matlab tool describing 2-Dimension (2-D) and 3-D simulation of a notional SOSE CONOPS. The tool can generate a set of potential SOSE architecture solutions with minimum performance degradation in the presence of RFI threats.
