Rotation PA -> Encoder Table for IGRINS

For a detailed Finder Chart and rotation setting see Kyle Kaplan's software. For rough rotations use the lookup table below.

193 = Default Encoder Setting at 90 deg. PA (slit east to west)

Position Angle (Start north and go east, N=0, E=90, S=180, W=270 degrees, Default = 90 deg slit oriented east-west)

(Encoder Setting) = 193 - 90 + (Position Angle) = 103 + (Position Angle)

WARNING: We recommend you do not rotate the instrument more than +/- 90 degrees from the nominal 90 degree position to avoid entangling wires and hoses.  The encoder setting limits are:

Positon AngleEncoder Setting
0,180103
15,195

118

30,210133
45,225148
60,240163
75,255178
90,270 (default)193 (default)
105,285208
120,300223

135,315

238
150,330253
165,345268
180,360283