Good morning.

(Want to get California Today by email? Here’s the sign-up.)

Self-flying cars are not here. But this past week in Tracy, Calif., a tech start-up called SkyRyse began testing a new emergency response service that it sees as a (small and careful) step toward passenger aircraft that can fly on their own.

Due for launch in January, the service will shuttle police officers and medical workers across the San Joaquin Valley via a helicopter equipped with the kind of sensors that power driverless cars. A radar sensor, for instance, provides a detailed view of the aircraft’s surroundings even in bad weather, not unlike the laser sensors used by the autonomous cars that are now being tested in places like Arizona and Texas.

At the moment, these sensors operate alongside seasoned pilots. But they will gather enormous amounts of flight data that can feed the creation of systems that can fly the helicopter on their own. In another echo of the work inside the makers of self-driving cars, SkyRyse engineers are using this data to build simulations of real-world flying conditions that can help test these systems.

SkyRyse is just one of many companies pushing toward this kind of technology, including Xwing, another Northern California start-up, and Uber, the ride-hailing company that is also building driverless cars. Uber is one of several companies working toward a kind of “flying taxi service.”