The problem with trying to estimate the capabilities of spy satellite cameras is that, because of its very nature, spy technology is kept under wraps by the government and great effort is made to block the tech from public scrutiny.
As such, any estimates made as to the capabilities of modern spy satellites would have to be based on a considerable amount of conjecture and educated guesses.
The spy satellite cameras that were created in the 1970s were so powerful that their images are still used today for research purposes, and are kept classified.
Super clear spy satellite cameras
The images taken from those satellites even beat the pictures taken from Google Earth in terms of resolution. If spy satellites used 30 years before the digital era could take such clear pictures, how powerful can the cam of today’s spy satellites be?
The basic size of modern satellite imagers is roughly the same size as that of Hubble. The pictures taken from these cameras is dependent on the satellite’s orbital altitude, their wavelengths and the state of the atmosphere surrounding them. Usually, distortion caused by atmosphere particles can cause a reduction in resolution by a factor of 2.
Pixel size cannot exceed two inches. This means modern satellites still don’t have the capability to read the letters printed on a piece of paper, or even allow for face-recognition capabilities.
Military grade cameras
Naturally, the military has invested a lot of time and resources in finding a way to overcome these limitations. One technique that the military is very good at employing is known as super-resolution imaging.
This capability has now been made available to the general public and is even a feature on many smartphones. Basically, you take several pictures of a scene and then choose the best pixels cherry picked from all the shots to create a mosaic of the various pixels in one complete picture.
This produces far more sharply defined pictures than anything taken by a single shot, but takes massive amounts of computational power.
The military has both the time and the money to invest extensive computational energy into creating a super-resolution image, which results in incredibly detailed shots of a kind that would be impossible to gain from a regular smartphone.
New developments all round
An interesting new development in the world of satellite imaging is that some companies now offer the services of a spy satellite to the regular public in return for a certain amount of money charged to their card.
These apps offer users the ability to change a satellite’s orbit and take photos of an area of Earth from space. While this basically amounts to having your own personal spy satellite, the satellite being used is still a commercial imaging satellite, no more powerful than Google Earth.
All said and done, however, it’s still impossible to state definitely just how powerful secret intelligence satellites are, since that kind of defeats the purpose of those satellites being ‘secret’.
Oftentimes, even when a photo is said to be taken by a spy satellite, it is actually a cover provided for secret agents working undercover in a hostile area when they are the ones who took the actual picture from the ground.
All we can say for certain is that spy satellites are far more powerful than Google Earth, or any other commercial imaging satellite that the general public has access to.