Spacecraft Zenith Variations

Test Over11 S/T/U Comparative Results

The measures of accuracy are plotted for each test in figures ?? to ?? under Tables and Figures (below).


Figure 1 illustrates the minimum uncertainty and RMSs for each test, and at which iteration each minimum occurs. The following patterns are apparent:

Formal Uncertainty and RMS

Residuals (Figure 2) maintain a value of approx. 3.1cm through the first 13 iterations, then decrease through the remainder of the first 50 iterations, seemingly forming an asymptote at approximately 1.4cm after approximately 55 iterations.

Despite the continuing decrease in formal uncertainties, the CompareOBJ RMSs (figure 4) achieve their minima around 1.0cm within the first 10 to 30 iterations and then increase monotonically with iterating, possibly beginning to round off at 2.2cm, a higher value than that achieved with the corresponding tiling step.

CompareOBJ with optimal translation and rotation (figure 5) achieves the minimum values around 0.5cm within 5 to 20 iterations. Increase in RMS is small with further iteration, remaining below 0.7cm.

With such a differing behavior between CompareOBJ and CompareOBJ with optimal translation and rotation, the tilting and drifting behavior of the bigmap should be investigated.


Comparison of the transit and heat plots shows that tilting and drifting behavior is consistent in direction and magnitude across tests S, T and U.


Before iterations begin, the North and West edges of the bigmap are low compared to the truth. South and East edges are on or below the truth.

Iterations 1 to 40:

The tilt worsens from the start of iteration to iteration 40 with the bigmap surface low on the North and West edges and high on the South and East edges. The mechanism driving the tilt appears to be the heightening of the South and East edges, although the entire bigmap increases in height through the iterations.

Iterations 41 to 100:

The tilt decreases through the remainder of the iterations, with the North and West edges increasing in height, reaching and then surpassing the height of the North and West edges of the truth topography. By 100 iterations, there is no discernible tilt remaining in the solution, but the entire solution is 2-4cm higher than the truth topography.

Tables and Figures

Figure 1: Minima


Figure 2: Formal Uncertainty


Figure 3: CompMapVec RMS


Figure 4: CompareOBJ RMS


Figure 5: CompareOBJ With Opt Tran & Rot



transitIt20200.png transposedTransitIt20200.png

transitIt40200.png transposedTransitIt40200.png

transitIt60200.png transposedTransitIt60200.png

transitIt80200.png transposedTransitIt80200.png

transitIt100200.png transposedTransitIt100200.png

Heat Plots

heatPlot-T11RFS-05stepB020-1cm-4m.png heatPlot-T11RFT-05stepB020-1cm-4m.png heatPlot-T11RFU-05stepB020-1cm-4m.png

heatPlot-T11RFS-05stepB040-1cm-4m.png heatPlot-T11RFT-05stepB040-1cm-4m.png heatPlot-T11RFU-05stepB040-1cm-4m.png

heatPlot-T11RFS-05stepB060-1cm-4m.png heatPlot-T11RFT-05stepB060-1cm-4m.png heatPlot-T11RFU-05stepB060-1cm-4m.png

heatPlot-T11RFS-05stepB080-1cm-4m.png heatPlot-T11RFT-05stepB080-1cm-4m.png heatPlot-T11RFU-05stepB080-1cm-4m.png

heatPlot-T11RFS-05stepB100-1cm-4m.png heatPlot-T11RFT-05stepB100-1cm-4m.png heatPlot-T11RFU-05stepB100-1cm-4m.png