Sentinel 2 images are freely accessible, paid by european citizens through the copernicus program. There's also landsat 8 images, of similar resolution (10m/pi

Sentinel 2 images are freely accessible, paid by european citizens through the copernicus program. There's also landsat 8 images, of similar resolution (10m/pixel for visible, lower in infrared bands). The revisit time depends on the latitude, but roughly you have a new image of the whole earth every week. Maybe that's too high res for your application?