Pointing test plan, Wayne Dahl

We've decided to run an elevation pointing test T920d first thing tonight. We can quickly find out (about 1 hour or less) if we've made an improvement to the model. Then segment exchange followed by T920b as planned.

I've changed the value for the azimuth encoder zeropoint offset from -37.15 to 44.7 arcsec. See /home/k1obs/qfix/k1AxeEnc.par. The backup file is k1AxeEnc.par.11jun03 in the same directory. The new value reflects the -81.85 arcsec value I had to add the zeropoint to recreate the curve that ca_ce_watch produced. We have to remove that so I changed IA the other way.

0) The new IA a.k.a AXZR will be loaded at the start of the evening.
1) Start ca_ce_watch - leave it running all night.
2) Start pointing test 920d

Test 1) It might be hard to find the first star (default CA will be bad) but the next stars should come in on target (or much better than before). If you see even worse pointing, the CA trend should be on one direction only (increasing CA with decreasing El). Go for a few more stars (try for 10) to really convince yourself what's going on with CA and abort the test. If it's noticeably better, continue with the test to completion. Call me 887-6619


Test 2) If pointing is way off and you abort the test, change the encoder zeropoint to -11.6 arcsec with the following commands (from k1server)

caput k1:dcs:axe:az:enc.AXZR -0.0000562271
caput k1:dcs:axe:az:enc.LOAD 1

caget k1:dcs:axe:az:enc.AXZR

and restart t290d. Again finding the first star might be a problem but follow-on stars should be easy.

Try to complete at least one full up or down if possible. Call me 887-6619


If you find that pointing isn't working, revert to last nights value of -37.15

caput k1:dcs:axe:az:enc.AXZR -0.000180108
caput k1:dcs:axe:az:enc.LOAD 1

caget k1:dcs:axe:az:enc.AXZR

And I'll sort out the results later.

My phone number at home 887-6619

Here are caput (from k1server) commands to load the new IA (encoder zeropoint) value (44.7 arcsec) if needed.

caput k1:dcs:axe:az:enc.AXZR 0.0002167117
caput k1:dcs:axe:az:enc.LOAD 1

caget k1:dcs:axe:az:enc.AXZR