IAS: J. Oberling

SEI: H. Radkins

 

Initial alignment of the HAM3 ISI has been completed, pending a final level/elevation check by Hugh.  Alignment was done by using 2 sets of crossed scales for x-axis position and rotation measurements and a corner cube for distance measurements for the y-axis position.

 

A smaller scale is mounted perpendicular to a larger scale with the smaller scale sitting horizontally and centered on the edge of the larger scale.  This assembly is then attached to a fixture (a "scale mounting fixture") designed to place the crossing point of the two scales on the centerline of the ISI table.  2 of these assemblies are used and mounted at opposite ends of the ISI table, ~2m apart.  This allows us to measure both x-axis (North/South) position and yaw rotation.  Measurements from both scales will be given, denoted by the side of the ISI table the scale is mounted on, East or West.  For the y-axis position, we know the location of the monument our equipment is set up on and the location of the East scale mounting fixture on the ISI table.  It is then a simple subtraction to calculate the required distance from the total station to the first scale mounting fixture to zero the ISI table on the y-axis; the distance is 2009.3mm.  Since the total station only reports distance to 1mm, we used 2009mm.  All specs for table position are ±1 mm (totat station EDM accuracy for y-axis position is ±2 mm, it's the best we can do with this equipment); specs for table rotation are ±100 µrad.

 

The measurements are: