Teachers' Venture Growth, part of the Ontario Teachers' Pension Plan, led the nine-year-old company's Series D funding round.

The latest investment brings Fleet's total venture funding to more than $165 million and values the company at $525 million, more than double its valuation from a Series C round last year.

Matt Pearson, Fleet cofounder and chief exploration officer, said the proceeds will help the company miniaturize mineral prospecting ground sensors that use its satellites to send seismic data to customers.

Fleet's ambient noise tomogra