How is Mars One planning on choosing a landing site? Will they be able to use NASA assets (Mars Reconnaissance Orbiter, etc) to assist with choosing a site, or will they have to make do with public sources?
From the Mars One Website:
According to the Mars One roadmap, a demonstration mission carrying proof of concept for some of the technologies and a communication satellite would be launched in January 2016. The communication satellite would arrive in orbit in October 2016 and would be able to relay images and videos from the surface of the Red Planet back to Earth.
The first settlement rover should arrive on the Red Planet in 2018, tasked to find the right location to establish the Martian village. Mission planners believe that the idea settlement site would be far enough north for the soil to contain water, equatorial enough for maximum solar power and flat enough for construction of the village. Once the ideal site is located, the rover would prepare the ground for the arrival of cargo supplies.
Bottom line is, a launch in 2016 to scout out potential areas to land will happen, followed by a settlement rover to better determine a landing spot, and finally cargo supplies will be sent out ahead of time. I strongly suspect that publicly available data will assist in landing site selection, and perhaps they will even use the HiWish system to request a few images, but as a whole, it seems like they are prepared to launch their own equipment to determine their landing site.