Overall Summary: August 1997 - January 2000

$\bullet$ 573 of 701 attended passes had max good data.

$\bullet$ Operators helped increase amount of good data in 65 of 135 ``bad'' attended passes.

$\bullet$ 62 of 106 unattended passes had max good data.

$\bullet$ Operators would have increased amount of good data in 25-28 of 45 ``bad'' unattended passes.

$\bullet$ A total of 5.45 tracking passes lost data due to software problems.

$\bullet$ A total of 40.62 tracking passes lost data due to hardware problems.

$\bullet$ A total of 42.71 tracking passes lost data due to problems with HALCA.

$\bullet$ SRT and orbit prediction file problems resulted in the loss of 4.23 tracking passes.

$\bullet$ Inclement weather resulted in the lost of 4.45 tracking passes.

$\bullet$ 157 of 209 recording passes gathered the maximum amount of valid data.

$\bullet$ 190 of 209 recording passes gathered 80% or more of the maximum amount of valid data.

$\bullet$ A total of 14.67 recording passes lost data.

$\bullet$ 81 of 84 tracking passes observed from the JOC were succesfull.

The attended tracking passes have an average of 82% which obtain the maximum amount of good data while unattended tracking passes average 59%. Operators have increased the amount of good data on 48% of the ``bad'' attended tracking passes. Operators would have increased the amount of good data on 56%-62% of the ``bad' unattended tracking passes. Unattended tracking passes have also resulted in at least three delays in detecting hardware errors. This possibly resulted in three or four other tracking passes have unnecessary 'bad' data if the hardware problem had been detected immediately.

A histogram of the success rate of the attended and unattended tracking passes is shown in Figure 71.1. A histogram has been made for both the attended and the unattended tracking passes. Each histogram has been normalized by the total number of tracking passes in that category. The histogram bins have a width of 5%. Figure 71.1  shows the overall success rate of the HALCA mission as observed in Green Bank.

It is easily seen from Figure 71.1  and the above summary that the unattended tracking passes have a success rate that is $\approx25$% less than that of the attended passes. Operators, on average, increase the amount of good data collected by about $\approx50$%. This average would hold true even for the unattended tracking passes.

Conclusions The data indicate that the presence of operators during tracking passes significantly increases the amount of valid data gathered.

Updated versions of this document will be made available at

http://www.gb.nrao.edu/ovlbi/summaryReport/index.html

  

  

Figure 71.1: Histogram comparing the success rates of attended and unattended tracking passes from August 1997 through June 1998.

  

Figure 71.2: Histogram showing the success rates of recording passes and non-recording passes from August 1997 through June 1998.