Noah opened the window of the ark and could see the tops of the mountains (Genesis 8.5, 6).
Then he sent out a raven. He also sent out a dove to see whether the waters had receded enough to expose the ground.
However, the dove did not find a resting place, but then,
“he waited yet another seven days, and again he sent the dove out from the ark” (Genesis 8.10).
The dove came back to him with a freshly plucked olive leaf in her mouth, and by that Noah knew that the waters had receded enough to expose trees and perhaps much more.
Then Noah did it again with the dove,
“So he waited yet another seven days and sent out the dove, which did not return again to him anymore” (Genesis 8.12).
Noah then knew that the ground was ready to receive all the animals and his family that were onboard.
Why did Noah wait seven days before sending out the dove the second and then the third times? I do not know that I have the answer, but it could simply be that he looked outside and could see conditions improving, but that he did not know how far out the land was ready for them.
At those seven day intervals things may have looked good to him, and the Lord had a hand in everything, and so God and man worked together to save the earth!