Three codes could be found in THE ANATOMY OF A TYCHO VISION post on the Investigate Ingress blog.

[1] 2n2vywta9ses8c

[2] totkywalobktkaxgrqzcuyzcua

[3] 4e57cicd5hqnxthe

Code #1

Observations

14 characters with the right amount of numbers for a valid passcode

Code #2

Observations

An old roman emperor will guide you to the solution

Code #3

Observations

16 characters with the right amount of numbers for a valid passcode