... The Observatory Monitoring System (OMS) is part of the Hubble Space Telescope (HST) ground system at the Space Telescope Science Institute. OMS receives as inputs a file of commands for the HST and files of engineering telemetry data generated by the HST in response to those commands. This paper will discuss how, from its inputs, OMS software provides spacecraft jitter files during observations commanded in the input. ... The jitter image file will be archived for the user. ...