The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part Bl. Beijing 2008 
From Sol 1466, Spirit settled on a north-facing slope 
(nicknamed Winter Haven) at the north side of Home Plate to 
survive the local winter. 
Figure 1. Spirit rover traverse map in the Home Plate area 
From Sol 743 to Sol 1514 of Spirit rover, we performed a local 
comparison of rover traverses in the Home Plate area, where 
Spirit experienced wheel slippage going up-slope and down- 
slope. Figure 2 shows a comparison of Spirit rover traverses 
computed from telemetry data (blue) and BA (red). In this area, 
the locally accumulated relative difference between the 
telemetry-derived traverse and the bundle-adjusted traverse 
ranged between 0.8 to 10.8 percent. The maximum relative 
difference of 10.8 percent (5.73 m over 52.92 m) was found on 
Sol 763, where Spirit had just traversed a large up-slope. The 
maximum absolute difference was 14.44 m, found between Sol 
783 and Sol 798 (The maximum accumulated error corrected 
was 66.6 m on Sol 525). This demonstrated that the BA was 
able to correct significant localization errors. We also found 
that the up-slope and down-slope slippages cancelled each other 
out to some extent. 
O SU Aötuwed Travesee 
Тшушй Basod am Ta&meary Oaf* 
MER A Rover Traveree Map 
At the Meridiani Planum landing site, BA was able to correct a 
localization error (mainly caused by wheel slippage) as large as 
21 percent within Eagle Crater (up to Sol 62). After leaving 
Eagle Crater, BA-based rover localization was impossible due 
to insufficient localization image data. Wherever we observed 
large features (e.g., craters), we used an alternative localization 
method, comparison of an orbital image base map and 
orthoimages generated from rover imagery. Though not as 
optimal as the BA method, this adjustment strategy enabled us 
to provide the 2D Opportunity traverse in a timely manner. 
Figure 3 shows the latest traverse of the Opportunity rover as of 
Sol 1503. Located in Victoria Crater, the rover is in Duck Bay 
and is planning to approach the vertical wall of Cape Verde. 
Figure 4 shows the rover traverse overlaid on a mosaic of 
Pancam images. Outcrop layers and geological features 
investigated by the rover are also labeled. The original Pancam 
images that form this mosaic were taken from the top of Cape 
Verde looking at the crater wall towards the southwest between 
Sol 959 and Sol 991. 
Figure 3. Opportunity rover traverse map at Victoria Crater 
Figure 2. Comparison of Spirit rover traverses in the Home 
Plate area. Blue line is the traverse computed from telemetry 
data and red line is the traverse corrected by the bundle 
adjustment method. 
Figure 4. Opportunity rover traverse (red) overlaid on Pancam 
image mosaic. Small white dots are rover locations. Outcrop 
layers and target features are marked as lines and larger dots.