October 25th

The retroreflecting has remained off of the telescope to try to get some time on sky to complete the run program.

Night time activity

The observations start at 01:35 when the wind speed was slightly lower that 20 m/s. First the telescope is collimated then we point the AO star at 2:25. The seeing values measured by the LBT DIMM are in the range 1.6 2.6.

1) 2:25-3:25 AOS offset command test. Because the seeing is too high to measure system performance we perform a test of the offset command from the AOS. The new command allows to do an offset of any amplitude in closed loop. This is achieved dividing the given offset command in smaller commands that can be handled by the offloading mechanism. The test is succesfull.

2) 3:25- 4:25 Closed loop test. We acquired some closed loop images at BIN1 1KHz With seeing value ranging betqeen 1.4 and 1.7. Wind speed is around 18m/s. The SR achieved shows a correlation with the seeing values.

3) 4:25-5:20 We did a test of the system offset accuracy in closed loop testing the repetability of the positioning on four points on the FoV placed at 1 arcsec from the center on X and Y axis (dice 5). Data reduction is ongoing

4) 5:20 We move the telescope to another AO star. The closed loop measurement start at 5:45 for some telescope difficulties in reacquiring the new target (see issue track about thin shell offload commands by D. Miller). A few measuremnt in closed loop BIn1 1Khz are acquired with seeing values in the range 1.2-1.7. The achieved SR variates between 60% and 20 % depending on the seeing value.

SW test

In the late afternoon (with dome closed) a test of the AOS with BP4 build of the TCS has been done. All test were passed. With the BP4 release of the TCS a AOS command is available to the operator to power on and off the adaptive secondary and the W unit without using the engennering interface. (see D. Miller email for more details).
Topic revision: r1 - 29 Oct 2010, AlfioPuglisi
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