Telescope scripts:

60 quasi-random positions in a 150'' box:
quasi_random_box150_pos60.sh

- MORE TO BE ADDED -

Tools to generate new telescope scripts:

The standard dither options in NEWFIRM include various grids and a random pattern within a box. However, optimal dither patterns ensure that dithers don't "bunch up" or underfill the box, by rejecting random positions that do not fulfill certain criteria (basically maintaining a minimum distance to the other points in the sequence).

The following SuperMongo script generates "quasi-random" positions in a box. The script picks each new position by generating 10 random positions and retaining the one which is farthest removed from the previous n positions, with n the number of frames used in the sky subtraction. Defaults are a box size of 150'' (i.e. ~4x the size of the gap between the 4 arrays), 60 positions, and n=9. The output is a file with 60 absolute x,y positions in a box centered on (0,0).

Script: dither.sm
Output: dither.dat

At the moment, NEWFIRM cannot read a list of pre-defined dither positions. A work-around is to generate another dither script with NEWFIRM, with the same number of positions, and then edit the script. This is automated with a shell script:

File generated by NEWFIRM software: DITHERSTARE3.sh
Shell script to replace positions: replace_offsets
Output (to be fed back to telescope): quasi_random_box150_pos60.sh

The output was generated with the following shell commands:

chmox +x replace_offsets
./replace_offsets DITHERSTARE3.sh dither.dat quasi_random_box150_pos60.sh

Note that the format of DITHERSTARE3.sh is subject to change. The current version was supplied by Mark Dickinson on March 18 2008, but a safer approach is to generate a new one at the telescope, and run the shell script on that one.