Tacnav umd email
It looks like you're looking for the email address of the Tactical Navigation (TACNAV) team at the University of Maryland (UMD).
After a quick search, I found that the TACNAV team at UMD is part of the Department of Aerospace Engineering, and their email address is:
Please note that this email address might be subject to change, and it's always a good idea to verify the email address through the university's website or by contacting the department directly.
If you have any specific questions or concerns, feel free to reach out to the TACNAV team at the above email address or through their website.