FIGURE 5-8 Recommended notional GMD-E radar architecture for homeland defense.
An uplink/downlink function should be included as a new radar mode. Assuming that the transmitter and receiver could be modified to pass the required information, this function is estimated to require 0.65 percent of the radar resources per interceptor for an in-flight target update (IFTU) every 10 sec, until the final 10 sec before intercept, where 65 percent might be required for IFTUs every 0.1 sec (classified Appendix J provides greater detail). In the unlikely event that two or more interceptors intercept within 10 sec of each other, they would have to share the resources and accept less frequent IFTUs.
Therefore, combined tracking and IFTU activity in the example above would require approximately 4-7 percent of the radar resources per target until 10 sec before intercept, corresponding to a radar system that could handle approximately 14-26 simultaneous targets, depending on their distance from the radar. The resource allocation is roughly proportional to the average target range.