Description of NIS Mirror Plane Test (31/2337):

Seq 7 (1,0,492,1,1,0,0,0,0)


Please refer to the diagram below which shows Eros at a fixed position, and shows the fov moving about the
fixed Eros.
 

                ___
               |   |      
               | . | 
          |    |   |        /|\
          |    |___|         |                           +y
1st scan  |                  |                           /|\
 240sec   |                  |                            |
          |                  |                            |
          |      o Eros      |                            x-------> + z
          |                  | reverse                  +x into page 
          |                  |  scan
          |                  | 240 sec
          |     ___          |
          |    |   |         |
         \|/   | . |         |
     wait here |   |          
     12 sec    |___|
              

 
NIS 45 (narrow and wide):
-----------------------
-600   Position the spacecraft so that center of NIS at mirror position 45 is 1 degree in the +y direction from Eros center. 
       Eros is outside the NIS fov.  targeting:  boresight = center of NIS 45 (from ground-based analysis 
                                 aimpoint = 1 deg elev, 270 az (nadir sun coord system) relative to Eros
                                 rollvector = z 
                                 roll ref calculated to keep sun in xz plane

 0     Begin a slewing scan that moves fov 'down' (in - y direction), crossing through Eros until it reaches 
       a position where the center of NIS fov is 1 deg in the -y direction from Eros center. The scan moves
       at .008333 deg/sec and goes for 240sec (total distance is 2 deg).

0      At the same time the slew begins,  execute NIS Seq 7 with SLIT selected (narrow fov). This sequence takes 492 individual 
        1 second spectra.


240    At the end of the slewing scan, there is a pause for 12 seconds where the fov is held still.

252    Slewing scan resumes but in the opposite direction, moving field of view up back through Eros to
        original starting position.  


492    End of reverse scan, fov at original starting position. End of Seq 7 execute (492 spectra). 
       Scan begins a pause (no slewing) for 12 seconds.

504    Scan reverses again, now taking fov DOWN as at time 0. Execute NIS Seq 7 again except this time with wide
       slit selected. Same thing happens as above with narrow slit.

744    Scan stops at 1 deg in -y from Eros,  and pauses for 12 seconds

756    Scan resumes in reverse direction, fov moving up again.

996    Scan stops at starting position. End Seq 7 execute.



Repeat above sequence for NIS positions 75, 125, 175, and 225.

MSI: For position 75 only, take one image every 12 seconds during the scan down and up for both narrow and
     wide NIS data taking periods.  A total of 84 images are taken, no break in the cycle of one every 12 sec.