More from the article...

... In order for GPS (and other satellite-based positioning systems) to work to its full extent, the aircraft's GPS receiver must be able to lock onto the signals of at least four satellites at once. Unfortunately this isn't always possible, due to factors such as atmospheric conditions or even intentional signal-jamming perpetrated by enemy forces.

The as-yet-unnamed new system, which is being developed by Australian firm Advanced Navigation and European missile manufacturer MBDA, swaps the GPS receiver for a downward-facing neuromorphic camera.

Also known as an event camera, a neuromorphic camera incorporates pixels that independently respond to changes in brightness as they occur. This functionality allows the camera to pick out much more detail than a traditional camera, and to perform better in low-light conditions. ...

@#4 ... in GPS denied environments. ...

Yup.
There are times when GPS does not work or seems to work but is not returning valid information, but precise location data is needed.

GPS is often jammed or spoofed in (I'll called it) sensitive areas, among other reasons for GPS not to work properly.

@#5 ... There are times when GPS does not work or seems to work but is not returning valid information, ...