Non-Sid Tracking with AO

1. PI
Al Conrad

2. Purpose of test:
Demonstrate an alternative method for observing nonsidereal objects with AO.

3. Test number
N/A

4. Test duration in hours
1.5 hours

5. Brief description of test
Observe the object in two modes. First, observe the object using the standard method with differential tracking disabled. Then repeat the observation with the same set up except that telescope differential tracking is now enabled using the new method. Confirm
a) that DCS and AO perform correctly and
b) that offloading occurs less frequently.
Procedure
1. Set up an xshow to continually monitor four DCS keywords: DTRACK, DRA, DDEC, DOFFGE
2. Acquire a nonsidereal object with differential rates in excess of 5 arcsec/hour.
3. Observe the object using the standard method with differential tracking disabled.
4. Record the tip/tilt offloads.
5. Stop observing and set up again on the same object, this time with differential tracking enabled as follows: DTRACK=enabled, DRA=dra, DDEC=ddec, DOFFGE=0 (Important: DOFFGE=0. Monitor DOFFGE and make sure that it does not get set to 1 inadvertently via SKY or some other tool).
6. Observe the object and confirm
a) that DCS and AO perform correctly and
b) that offloading occurs less frequently.

6. Telescope/instrument configuration required
NIRC2/AO

7. Plan for data reduction, analysis, and reporting:
We apply this procedure to archive tip-tilt offloading during the differential tracking test
1) log onto kalama as k2tel (password *p…)
2) cd eng/arReq
3) arc aoTipTilt k2 ac
a. enter run number[00]: {hit return}
b. Output file will be placed in /nightly2/tonight/k2ac00.aoTipTilt
c. Starting AR…
d. Press Quit at completion of archiving
e. Starting ARR
f. Press QUIT at completion of analysis.
We then analyze these archive files and determine if the new method requries less offloading.

8. Preferred dates of observations and dates to avoid
N/A

9. Status and progress reports from previous use of engineering time
On September 29th Antonin and I ran this test with Titan. The first criteria (6a above) was demonstrated, but Titan was too slow moving to be able to confirm any offload performance improvement (criteria 6b).