Dear all,<br> Just for your information, the survey uncertainty is <br>0.15 mm for each axis direction.<br><br><div class="gmail_quote">---------- Forwarded message ----------<br>From: <b class="gmail_sendername">Christopher J. Curtis</b> <<a href="mailto:curtis@jlab.org">curtis@jlab.org</a>><br>
Date: Wed, Aug 14, 2013 at 2:19 PM<br>Subject: Re: uncertainty of survey results<br>To: Jixie Zhang <<a href="mailto:jixie@jlab.org">jixie@jlab.org</a>><br>Cc: Min Huang <<a href="mailto:mhuang@jlab.org">mhuang@jlab.org</a>><br>
<br><br>Jixie,<br>
I have looked over results from this period, including spectrometers, sieves and harps. A good value for the uncertainty of a single point would be 0.15mm. This would be the component of the uncertainty in each of the 3 directions (Z, X, Y). Although individual surveys will vary from this, and each of the axes may be slightly different, this is the average value determined from several surveys.<br>
Hope this helps,<br>
Chris<br>
<div class="HOEnZb"><div class="h5"><br>
----- Original Message -----<br>
From: "Jixie Zhang" <<a href="mailto:jixie@jlab.org">jixie@jlab.org</a>><br>
To: "Chris Curtis" <<a href="mailto:curtis@jlab.org">curtis@jlab.org</a>><br>
Cc: "Min Huang" <<a href="mailto:mhuang@jlab.org">mhuang@jlab.org</a>>, <a href="mailto:jixie@jlab.org">jixie@jlab.org</a><br>
Sent: Monday, August 12, 2013 2:44:06 PM<br>
Subject: uncertainty of survey results<br>
<br>
Dear Chris,<br>
<br>
We are working on spectrometer optics for Hall A g2p|gep experiments.<br>
We need to estimate the uncertainty of the optics. One of the major sources<br>
of the uncertainty is the uncertainty of survey results.<br>
<br>
In our case, the absolute position of HARP and HRS and Sieve Slits came from<br>
surveys. I have put all our servey reports here:<br>
<br>
<a href="http://hallaweb.jlab.org/experiment/g2p/survey">http://hallaweb.jlab.org/experiment/g2p/survey</a><br>
<br>
The HRS survey reports is here:<br>
<a href="http://hallaweb.jlab.org/experiment/g2p/survey/A1435_HRS_20120309.pdf">http://hallaweb.jlab.org/experiment/g2p/survey/A1435_HRS_20120309.pdf</a><br>
<a href="http://hallaweb.jlab.org/experiment/g2p/survey/A1463_HRS_20120529.pdf">http://hallaweb.jlab.org/experiment/g2p/survey/A1463_HRS_20120529.pdf</a><br>
<br>
Would you please send me the uncertainty of survey results of the following:<br>
<br>
1) uncertainty in horizontal left|right<br>
<br>
2) uncertainty in vertical up|down<br>
<br>
3) uncertainty in beam line direction,<br>
<br>
<br>
If the above uncertainties are different from location to location, please<br>
also let us know.<br>
<br>
--<br>
With Best Regards,<br>
Jixie Zhang<br>
<a href="tel:757-269-7735">757-269-7735</a><br>
_______________________________________________<br>
</div></div></div><br><br clear="all"><br>-- <br>With Best Regards,<br>Jixie Zhang<br>757-269-7735 <br>_______________________________________________