Obviously, we always try to optimize sensors for the potential threats that may be coming, especially on the approaches to North America. In our case, sensors have been cued to detect long-range aviation. We've worked on sensors to detect potential cruise missiles, which are one of the predominant threats out there, as seen in other regions.
With the detection of the PRC high-altitude surveillance balloon around the end of January and early February, at NORAD we went back and did data interpretation and data analysis. We tweaked the filter—it normally is called a gate, but I'll use the word “filter”—that we use to discriminate from just radar anomalies to be able to detect objects with a lower speed and a lower radar cross-section. Obviously, by lowering the gate or the filter, we end up with the risk of having more false contacts. That happens. Radar can detect dust particles in the wind, potentially, or birds that are travelling. That may lead to false contact.
That's an element that we're cognizant of and that we're going to be monitoring. That tweaking of the radar is probably what enabled the detection of the follow-on objects in the last couple of weeks.