The Sapienza computer scientists say Wi-Fi signals offer superior surveillance potential compared to cameras because they’re not affected by light conditions, can penetrate walls and other obstacles, and they’re more privacy-preserving than visual images.
[…] The Rome-based researchers who proposed WhoFi claim their technique makes accurate matches on the public NTU-Fi dataset up to 95.5 percent of the time when the deep neural network uses the transformer encoding architecture.
WiFi uses a subset of the significantly wider microwave band. Ground Penetrating Radar also uses a subset of the microwave band. While there can be some overlap, the frequencies desired for GPR will very broadly based on what you are looking for, what you are looking in, and how deep you are looking for that thing. The wattage supplied can also differ.
WiFi and Microwaves in general are most definitely not the same thing and I will absolutely encourage you to not set up a 1kW 3GHz jamming antenna for your WiFi needs.
Could you use WiFi for search and rescue? Maybe for a narrow set of circumstances, but in almost all situations a dedicated GPR option will be better.
This also won’t identify a victim, only revealing that one exists.