With the APT several special requirements can be specified in a purely visually manner, such as orientation in the Visual Target Tuner. However, in all cases users can specify the option from a spreadsheet view, where they will typically be provided textually through menu choices.
The table below lists the special requirements, the number of proposals that used the requirement in Cycle 8 which had 436 proposals, and the means of specification in APT. Notice that the more frequently used special requirements can generally be specified graphically. In that case, the user need not think of these specifications in terms of "special requirements". However, they will be listed as such in other views, such as the spreadsheet view. Furthermore, they will be listed as special requirements in the report on the proposal (as currently provided by the Description Generator).
--------------------------------------------------- VISIT/EXPOSURE LEVEL SPEC REQS FOR CYCLE 8 PROPOSALS TOTAL SPECIAL REQUIREMENT PROPS APT INPUT/EDITING TOOLS ----------------------------------- ----- ------------------------ ORIENT 173 Textually & VTT BETWEEN 103 Textually & visit planner SCHED 88 Textually & visit planner AFTER BY 57 Textually & visit planner SAME ORIENT 43 Textually & visit planner BEFORE 32 Textually & visit planner GROUP WITHIN 32 Textually & visit planner PCS MODE 30 Textually & visit planner CVZ 30 Textually, orbit planner, VTT ON HOLD 28 Textually & visit status tool (if tool happens) SEQUENTIAL WITHIN 24 Textually & visit planner PAR 21 Textually VISIBILITY INTERVAL 15 Textually ORIENT FROM 11 Textually & visit planner PERIOD AND ZERO PHASE 7 Textually ON HOLD FOR 6 Textually & visit status tool (if tool happens) AFTER 4 Textually & visit planner GUID TOL 2 Textually DROP TO GYRO IF NECESSARY 2 Textually ORIENT FROM NOMINAL 1 Textually DROP TO GYRO IF NECESSARY NO REACQ 1 Textually POS TARG 143 Textually & VTT MAX DUR 88 Textually & orbit planner NO SPLIT 80 Textually & orbit planner GS ACQ SCENARIO 71 Textually ONBOARD ACQ 64 SEQ NON-INT 62 Textually & orbit planner SAME POS 47 Textually & VTT EXPAND 44 Textually MIN DUR 28 Textually PAR WITH 25 Textually & orbit planner END ORBIT 25 Textually SAME ALIGNMENT 23 Textually & orbit planner LOW-SKY 11 Textually NEW ALIGNMENT 9 Textually NEW OBSET FULL ACQ 7 Textually PHASE 7 Textually REQ EPHEM CORR 6 Textually SHADOW 4 Textually RT ANALYSIS 3 Textually SAA CONTOUR 3 Textually REQ UPLINK 3 Textually SAME OBSET 1 Textually USE OFFSET 1 Textually SAVE OFFSET 1 Textually EXP PCS MODE 1 Textually SAME GUIDE STARS 1 Textually OBSET ID 1 Textually NEW OBSET 1 Textually