Test 05: OptimalF2

Aim and Objectives

Purpose of test: To obtain highest possible topographic accuracy and resolution for TAG site 1, given perfect camera position and pointing and optimal SPC image suite.

Additional Objectives

• To obtain user-in-the-loop and server-in-the-loop RMS error variations.
• To obtain user-in-the-loop procedural variation.
• To obtain beginner/expert user variation.

Methodology

Data

• Data was generated by Imager_mg using shape3.8 on ormacsrv1.
• PT10A - Centered at the middle of TAG site one.
• Image Suite: Optimal flight path, image resolutions: 50cm, 20cm, 10cm, 5cm.
  • S/C:
    • Every 20° azimuth angle, 45° zenith angle
  • Sun:
    • 0, 90°, 180°, 270° azimuth angle, 45 zenith angle
    • 135° azimuth angle, 30° zenith angle

Spacecraft:

Sun:

User/Server-in-the-loop:

Bigmaps

The following TAG1 bigmaps were tiled/iterated and evaluated:

Starting topography defined from: START1.MAP:

• GSD = 25cm;
• Q size = 150;
• width = 75m;
• center lat/wlong = -8.027, 262.768.

DTM Bigmap parameters:

Evaluation Bigmap parameters:

• GSD = 5cm;
• Q size = 500;
• width = 50m;

Tiling Parameters

Tiling parameters may have varied between users:

Iteration Parameters

Iteration parameters varied between users:

Results

Please see Tables and Figures.

Discussion

User Differences in Tiling and Iteration Parameters

The only differences in tiling parameters pertain to the auto-elimination of images during the initial 35cm tiling. The maximum permissible emission angle varied between 50 and 60 degrees. The minimum allowable ration between image scale and misplace varied between 0 and 0.25. All other tiling step parameters were the same between users.

Iteration parameters however varied greatly between users, with no two users applying an identical set of parameters. All users calculated the central vector (v1), however not all users reset albedo/slopes, conditioned with differential stereo and/or conditioned with shadows.

User Differences in Processing Steps

Since users had different criteria for triggering the cessation of iteration and continuing to the next tiling step (such as 2 iterations per tiling step, or, no further change in evaluation statistics), users iterated solutions a varied number of times.

Number of iterations conducted at each GSD step:

User Errors

Additionally, two users applied incorrect or non-standard processing procedures for some portion of the test related to their level of experience and training:

• DLambert calculated statistics on an incorrectly sized evaluation bigmap during the 35cm tiling and first iteration leading to loss of statistics data for these processing steps;
• DLambert failed to eliminate low correlating images during the first three 35cm iteration steps, leading to initial problems in the topography which are reflected in the formal uncertainties and RMS errors. The errors receded at the 18cm tiling step.
• KDrozd used different parameters in the utility program FITS2OBJ, upstream of obtaining the CompareOBJ RMS error, as other team members, leading to differing RMS error statistics which do not necessarily reflect differences in the evaluation bigmap compared to other users' bigmaps.

User Differences in Evaluation Statistics

Conclusions and Recommendations

Tables and Figures

RMS Distance (cm) - Compare OBJ

Formal Uncertainty (cm) - RESIDUALS

35cm GSD Maplets - 50cm Resolution Images

18cm GSD Maplets - 20cm Resolution Images

9cm GSD Maplets - 10cm Resolution Images