2002 td tensions vs td positions,platform temp, platform hght, and fits

feb,2003

links to plots:

avgTotKips,temp,platformhght,and Difference in cable tensions for 2002
Cable tension differences at constant temperature.
fit residuals for totalKips(temp,platformHght) using all the data.
fit residuals for totalKips(temp,platformHght) using 6am to 8pm.
fit residuals for totalKips(temp,platformHght) using 8pm to 6am.
fit residuals for totalKips(temp,avgTdPos) using all the data.
the TotalTension2000-TotalTension2002

Sections:

The measured data for 2002.
Fitting totalTension(temp,platformHght):
Fitting totalTension(temp,avgTdPos)
Fitting tension1Td(temp,tdpos[3],az,za)
Comparing the tensions for 2000 and 2002.


Intro

 The platform height and tempurature is recorded once every two minutes. The tiedown position and tensions are recorded once a second. This data set is interpolated to integral minutes and recorded (see looking at platform position, temp, and tensions). The data for 2002 is shown below.
The following fits were done:   The fits have been added to the idl routines in ~phil/idl/prf (@prfinit)


The measured data for 2002.


Fitting the tensions..

    The data used for fitting met the following criteria:
  • temp gt 60 and less than 95
  • platform position within .4 feet of 1256.35
  • tension in 1 cable gt 4 kips and less then 65 kips (when calibrating).
  • A linear ramp was removed from td8_1 for may through oct.
  • Fitting totalTension(temp,platformHght):

        Fits were done for all day, 6am to 8pm, and 8pm to 6am. The plots show the fit residuals versus date,hour,hght,and temperature.
    1. fit residuals for totalKips(temp,platformHght) using all the data.
    2. fit residuals for totalKips(temp,platformHght) using 6am to 8pm.
    3. fit residuals for totalKips(temp,platformHght) using 8pm to 6am.
    totalTension(temp,platformHght)
    time
    constant (kips)
    @74F,hght=1256.35
    kips/
    degF
    kips/
    PlatformInch
    rms(kips)
    npts
    allday
    122.7
    -5.11
    -8.78
    5.8
    274400
    6am-8pm
    120.9
    -5.03
    -8.67
    6.0
    166945
    8pm-6am
    129.4
    -3.66
    -9.12
    2.8
    107407


    Fitting totalTension(temp,avgTdPos)

        A fit was done with all the data using the temperature and the average tiedown position.
    1. fit residuals for totalKips(temp,avgTdPos) using all the data.
    totalTension(temp,avgTdPos)
    time
    constant(kips)
    T=0F,tdPos=0
    kips/
    degF
    kips/
    avgTdInch
    rms(kips)
    npts
    allday
    245.4
    -2.74
    6.90
    3.90
    274562

        The temperature dependence varies in the two fits because different things are being meausured. The temperature variation of the first fit is when the platform is held constant. The 2nd temperature dependence is at constant tiedown jack position but the platform is allowed to move.


    Fitting tension1Td(temp,tdpos[3],az,za)

        The tension in each pair of tiedowns was fit for the az,za,temp, and position of the 3 tiedowns. The fit residuals (for the tension on 1 block) were 1.5,1.7, and 2.2 kips for td12,td4, and td8.


    Comparing the tensions of  2000 with 2002.

        The previous model for tension(temp,hght) and tension(temp,tdPos) was made with data from april,may 2000. During this period we were not actively tracking the average platform height with the tiedowns.

        The plot shows the TotalTension2000-TotalTension2002 using the models of Kips(temp,platformhght) and kips(temp,tdAvgPosition). The fits were evaluated at the temp and hghts measured for 2002. The black line is the difference of the fits totKips(temp,platformHght). The red line is the difference in the fits for kipsTot(temp,avgtdpos).  The difference of 15 to 20 kips would occur if additional weight was added to the platform. Increasing the weight would decrease the tension needed to maintain the platform at a particular height.
     

    processing: x101/td/model/2002/doplot.pro,yr2002FitGetDat.pro, year2002FitDat.pro
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