Constellations of satellites for Optical Earth Observations

Being able to access maps of any part of the globe updated on daily basis whenever necessary could have important benefits for scientific reason as well as for better emergencies evaluations.

Constellations can avoid one of the most common problems with Earth Optical Observations from satellite. Clouds covering a region and blocking the view. If there’s one single satellite that passes over a region every 30 days and there’s a cloudy day it may be necessary to wait till next time the satellite will be above the same region, 30 days later. Doubling the observation time for many applications is not acceptable.

Most of the time different satellite operators, from different countries, may share data solving the problem, perhaps with only some days of delay.

Why is the update frequency of the maps important?

Agricultural improvements. Instead of receiving data once each month, being able to access information everyday on crops and soil condition that may allow farmers to deal with droughts more efficiently increasing the overall productivity.

Emergencies like earthquakes, floods, forest fires, humanitarian crisis etc. All these need rapid information in order to coordinate the emergency teams more efficiently. For example in case of earthquakes or floods it could be possible to identify places with major damage or obstacles that could slow emergency teams.

Planet Labs is a company that works with a constellation of optical satellites (Doves) many about 10x10x30 cm in size. They manage to create maps of the whole globe updated on daily basis. Gallery of some of their photos from space.