Retaking the SAT???

Hi guys, I’m a senior at high school who is considering applying top tier schools during my junior or sophomore year of college. A lot of top tier colleges such as Stanford, Columbia, and Dartmouth require transfer applicants to submit theirs SAT scores. Does this mean I can take the SAT again while I’m in college as an undergraduate student? I took the SAT during junior and senior year of high school but was not satisfied with my score. Please help me!!! Also please give me some advice as I am trying to transfer to those schools as a transfer applicants from community college. Thank you in advance!