Deserts are actually better than over the ocean if they are dark enough. You want no ambient light and very dry air.
Two things that surprised me about the desert. One, they are surprisingly cold at night. Two, they can be very wet and have tons of particles in the air during certain seasons. Who knew. It makes sense since cooler air decreases the amount of moisture that the air can hold, but for some reason that thought never occurred to me. Perhaps your Martian atmosphere is cold enough that very little moisture is left in it brother brush hat[;)]
