= Spacecraft Zenith Variations =

== Aim and Objectives ==

'''Purpose of Test 11:''' To evaluate SPC's ability to represent a simplified 'boulder' which has a constant 20 degree slope.

'''Objective for Test 11 S, T & U, Spacecraft Zenith Variations''' 
 * To investigate the effect of varying the combination of spacecraft zenith (emission angle) contained in the image suite;
 * To investigate the effect of the number of images and viewing conditions.

== Methodology ==

The 'boulder' was simulated by generating a simple axe-symmetric, flat-topped cone (peak) with a constant 20 degree slope. Multiple peaks and (simplified) craters are randomly placed in an otherwise flat landscape of width approx. 22.5m.

'''Truth map:''' REGION.MAP

'''Bigmaps'''

The following TAG1 bigmaps were tiled/iterated and evaluated:

Starting topography defined from: START1.MAP at pixel/line location 49, 49 (= REGION.MAP at p/l 1125, 1125).

||Step||GSD||Overlap Ratio||Q Size||Width||Center||
||START.MAP||20cm||-||49||20m||REGION.MAP p/l 1125, 1125 (center)||
||10cm-Tiling||10cm||1.3||130||20m||START1.MAP, p/l 49, 49||
||5cm-Tiling||5cm||1.3||250||20m||START1.MAP, p/l 49, 49||
||5cm-Iterations||5cm||-||-||20m||START1.MAP, p/l 49, 49||
||Evaluation Map||1cm||-||200||4m||REGION.MAP, p/l 996, 1005||

'''Tiling/Iteration Parameters'''

||Auto-Elimination Parameters:||0, 60, .25, .25, 0, 3||
||Reset albedo/slopes||NO||
||Determine Central Vector||YES||
||Differential Stereo||YES||
||Shadows||YES||

'''Tiling seed files:'''
[[Test Over11STU t11-10.seed|t11-10.seed]] ,
[[Test Over11STU t11-05.seed|t11-05.seed]]

'''Iteration seed file :'''
[[Test Over11STU Piterate2StSh-withoutayy.seed|Piteate2StSh-woAYY]]

'''Data'''
 * Data was generated by ??.  
 * Image resolutions: 2cm/pixel.

'''Viewing Conditions'''
|| Name || Sun || S/C Az || S/C Zenith || Total Number of Images ||
|| Test11S || 45, 0, -45 || every 45 || 0, 30, 60 || 80 ||
|| Test11T || 45, 0, -45 || every 45 || 0, 20, 40, 60 || 112 ||
|| Test11U || 45, 0, -45 || every 45 || 0, 15, 30, 45, 60 || 144 ||

Note that a larger image suite was planned and produced than was utilized during test. The images for a number of planned viewing conditions were eliminated due to image quality related to the viewing conditions being unfit for SPC. For further details are contained here: 

[[Test11STU Unsuitable Viewing Conditions]].

'''Test11S Viewing Conditions'''

{{attachment:Over11S_EE0057_sc_plot_resized.png}}
{{attachment:Over11S_EE0057_sun_plot_resized.png}}

'''Test11T Viewing Conditions'''

{{attachment:Over11T_EE0057_sc_plot_resized.png}}
{{attachment:Over11T_EE0057_sun_plot_resized.png}}

'''Test11U Viewing Conditions'''

{{attachment:Over11U_EE0057_sc_plot_resized.png}}
{{attachment:Over11U_EE0057_sun_plot_resized.png}}


== Results ==

'''Results with Overlaps:'''

[[Test Over11STU Comparative Results]]

[[Test Over11S Results]]

[[Test Over11T Results]]

[[Test Over11U Results]]

'''Results without Overlaps:'''

[[Test11S Results]]

[[Test11T Results]]

[[Test11U Results]]


== Discussion ==

From an inspection of the minimum formal uncertainty, CompMapVec RMS and CompareOBJ RMS (both the minimum value and the number of iterations at which the minimum occurs), for tests S, T and U, the following is apparent.
'''Within-measure range of minima:'''
||Formal Uncertainty||1.511 +/- 0.087 cm||
||CompMapVec RMS||0.875 +/- 0.325 cm||
||CompareOBJ RMS||0.938 +/- 0.097 cm||
||CompareOBJ with Optimal Trans & Rot||0.435 +/- 0.072 cm||

== Conclusion ==