386 as a function of realistic  RWA operating speeds, are dominant can demand extensive test data and  analytical exercises. However, if some ratios are found to be  closely correlated, there is the potential to  extrapolate or  bound overall IV with substantially reduced testing/ post-test analysis ( i.e., early analyses  results can support that  a limited test data set affirm s upper -level jitter requirement compliance thereby  reducing test dat a collection). It is  highly desirable that clear,  robust trends emerge readily  from  straightforward examinations of the IV data collection ; e.g., testing a hypothesis that radial force primary  unbalance (1.0 harmonic) consistently tracks and predicts axial  force 1.0 harmonic (or other ratios) IV data.  This data set provides, for the first time, a  viable  opportunity  to quantify potential correlations once any  particular rotor -bearing physic al properties  / harmonic  relationships  are known  within consistent  bounds .  This creates  a practicable set (12)  of candidate correlations  (relying upon the 4 key harmonic ratios)  within  each DOF  (3; axial force, radial force, radial moment) and dual ratios  (4; 1.0 -to-2.0, 1.0 -to-2.8, 1.0- to-5.2,  and 2.8- to-5.2). Extending  further, 12 DOF cross- axis pairings are correlated (12; same- ratio pairs ). If no  strong cor relations exist  within these 24 IV pairings  (some are, in first-order theory, tied to the same root  imperfection; while some are not), then reaching for even more obscure relationships would not likely be  fruitful for the efforts expended (e.g., test data collection system  noise dominates relationships) . Until such  analysis is conducted, there is no solid analytical basis for common relationships in  data sets or root  imperfections . The E GE methodology  discussed above (via 2nd-order coefficients)  serves as  a common basis  for cross -harmonic comparisons . IV harmonics with relatively  poor and  good correlations  are in Figu re 10:   EGEs in units shown above.  Summarizing, results are mixed yielding some but few strong correlations.  

Figure 10 : Examples of Relatively Low  (AF1.0-AF2.0) & High  (RF1.0-RM1.0) IV Data  Correlations  

RWA IV Analytical Assessment Investigation Overview /Summary    Multiple  flight IV datasets, addressing known/available RWA vib rational and variability data sources, are   researched, analyzed,  and compiled herein ; a valuable reference for comprehensive RWA jitter analysis  characterizations. Specifically, this treatise:  1) collects, compares, and statistically evaluates 4 dominant  harmonics for 20 IV ground- based data s ets in local principal RWA axes , 2) exposes rationale for the  relative dominance of those 4 harmonics for jitter  predictions , and 3) presents comparative data  on 32  previously undetected/unknown less prominent harmonics. Values are presented via a combination of  summary tables and graphs. This  also provides fundamental insights for  pre-determining rotor -bearing  factors driving IV harmonic ratios, estimating sam e-size/design bearing characteristics,  and solidifying the  validity, applicability , and robustness  of IV measurements when several factors are considered that may  significantly skew actual LOS on- orbit jitter  amounts  away from test-based analytically -predi cted values.  

Specific Basis, Background, and Objectives f or Overall RWA IV Dataset Investigation Effort    Effects potentially impacting IV values (and are present in ground- to-orbit transitions ) have been explored  with the RWA supplier’s SMEs and summarized below . Specific IV study super -objectives are:    1) determine values  and ferret out attributable root causes of I V known variations that directly affect   groun d-ambient measured I V test data value differences , and  y = 0.3293x R² = 0.1138 0.0001.0002.0003.000 0.000 2.000 4.000 6.000 8.000Correlation: Axial Force 1.0 -to-2.0 Harm. EGEs               AF 1.0 vs. 2.0 y = 5.2679x R² = 0.6618 0102030405060708090100 0.000 5.000 10.000 15.000Correlation: Rad. Force 1.0 -to-RM Harm. EGEs               RF 1.0 vs. RM…