The sources I used were:
- ESRI World Imagery[1] — free satellite tiles, high-res, but ships are stripped out from the imagery
- NASA GIBS - VIIRS[2] — near real-time daily satellite imagery from NASA, but resolution is ~375m so ships aren't visible anyway
- Mapbox Satellite[3] — high-res and looks great, but same deal — ships are scrubbed from the composited imagery
1. https://server.arcgisonline.com/ArcGIS/rest/services/World_I... 2. https://earthdata.nasa.gov/engage/open-data-services-softwar... 3. https://www.mapbox.com
- Sentinel-2 (10 m/pixel): https://github.com/allenai/rslearn_projects/blob/master/docs...
- Landsat (15-30 m/pixel): https://github.com/allenai/rslearn_projects/blob/master/docs...
- VIIRS Nighttime Lights: https://github.com/allenai/vessel-detection-viirs
I think you can see these vessel detections at https://app.skylight.earth/ ("Try out a limited version as a guest") but they seem to be delayed by 48 hours.
VIIRS is very low resolution but you can make out vessels with reasonable accuracy in the night-time images.
VIIRS covers most locations at least once per day, but the other sensors capture a given location only once per 5-10 days (although when combined, Sentinel-1/Sentinel-2/Landsat should provide close-to-daily coverage).
https://windward.ai/blog/gps-jamming-disrupts-1100-ships-in-...
you could, presumably, mess up other instruments than visual to interfere with enemy countries
and you just know governments will do supply chain style attacks.
Crypto AG cia front company, encryption devices
backdoor in RSA key generation by nsa
exploding pagers
usa installing bugs in enterprise router exports
doesn't this sort of thing invalidate any kind of experiment because the instrument is no longer trustworthy
Ships don't move that quickly; AIS data refreshed once every few hours would probably be more than good enough.
By not providing imagery of the ocean surface, it also gets to display ocean floor topography data it wouldn't otherwise get to show without having to add another mode.
I assume another reason is that it reduces the total size of the imagery, which would have been a plus on the 2001 computers that Google Earth was originally developed on.
I believe you can get this imagery from other sources (aside from things that are government-censored), but you face the same problem Google did in how to stitch it together without it being a patchwork of different moments in time.