= 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 combinations of viewing conditions which comprise the image suite, specifically:
  * Variation of spacecraft zenith (emission angle);
 * 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. Two boulder simulations were generated:
 * A single peak in an otherwise flat landscape of width 5m - Modeled using a single maplet (no overlaps).
 * Multiple peaks and (simplified) craters in an otherwise flat landscape of width approx. 22.5m.

'''Data'''
 * Data was generated by .
 * Location and parameters for evaluation area.  
 * Image resolutions: 2cm/pixel.

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]].

|| 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 ||

'''Test11S'''

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

'''Test11T'''

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

'''Test11U'''

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

'''Bigmaps'''

The following TAG1 bigmaps were tiled/iterated and evaluated:

Starting topography defined from: START1.MAP at pixel/line location 49, 49.

||Step||GSD||Overlap Ratio||Q Size||Width||
||10cm-Tiling||10cm||1.3||130||20m||
||5cm-Tiling||5cm||1.3||250||20m||
||5cm-Iterations||5cm||-||-||20m||

'''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

== 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 ==