In the US, these folks are termed "Referee Inspectors" and a description of their role is here from US Soccer, and below:
U.S. Soccer will appoint certain National Assessors as Referee Inspectors. This designation is at the discretion of U.S. Soccer and is reviewable at any time. Referee Inspectors will be empowered to assess all games but specifically at the Pro-Level and international level. In addition, all National Referees and National Candidates must have at least one of their annual assessments as a referee conducted by a Referee Inspector.
It gives me great pleasure to announce both Ed Rae and Erich Simmons as two of the newest US Soccer referee inspectors for 2011.
Please join me in congratulating them on this significant accomplishment!