v i. iS | i 
BUNDLE ADJUSTMENT OF MARS HIRISE ORBITER STEREO IMAGES BASED ON 
THE RIGOROUS SENSOR MODEL 
Yunhang Chen 
Mapping and GIS Laboratory, Dept, of Civil and Env. Eng. & Geodetic Science 
The Ohio State University 
470 Hitchcock Hall, 2070 Neil Avenue, Columbus, OH 43210-1275 
chen. 1256@osu.edu 
KEY WORDS: Digital Photogrammetry, Sensor Models, Adjustment, Topographic Mapping, High Resolution Image, Extraterrestrial 
ABSTRACT: 
Launched in August 2005, the Mars Reconnaissance Orbiter (MRO)’s primary goal is to obtain detailed morphologic information on 
the Martian surface using its onboard HiRISE sensor with a 0.3-meter ground resolution. However, inconsistencies between HiRISE 
stereo images must be removed based on the rigorous sensor model for the best level of accuracy. The new rigorous sensor model is 
developed specially for HiRISE due to its unusual complex camera design so that the mosaic of multiple image strips could be 
processed simultaneously under a uniform sensor model. A bundle adjustment (BA) based on this rigorous sensor model is 
implemented on two stereo pairs covering Husband Hill and Victoria Crater. After BA, the significantly reduced back projection 
residuals indicate that the inconsistencies are removed and the refined exterior orientation parameters are ready for mapping the 
Martian surface. Furthermore, 4 ground points measured from geo-registered Spirit rover images are incorporated into the BA as 
ground control points. Reduced inconsistencies on ground features between orbital intersection and measurements from rover images 
after BA indicate the mapping potential of orbital-ground integration. Small motions of the spacecraft around its nominal pointing, 
called jitter, has been detected on HiRISE trajectory data. The topographic effect of jitter is evaluated in this paper. Though its effect 
is insignificant when mapping small areas, further investigation needs to be performed so that the effect can be removed or reduced 
when mapping large areas. 
1. INTRODUCTION 
The Mars Reconnaissance Orbiter (MRO) has collected mapping 
data at an unprecedented level of accuracy on the Martian surface. 
Its primary scientific objectives are to characterize the surface, 
subsurface and atmosphere of Mars and to identify potential 
landing sites for future missions (NASA/JPL). HiRISE, the linear 
pushbroom image sensor onboard MRO, provides images with 
up to 0.3-meter resolution. This ultra-high resolution makes great 
progress possible in the derivation of topographic information on 
the Martian surface. 
In order to support the Opportunity rover operation in the 2003 
Mars Exploration Rover (MER) mission, a DEM of Victoria 
Crater was generated by USGS using HiRISE stereo images. A 
program was used to transform input raw images by projecting 
them into ground coordinates and then back into the image 
coordinates of an idealized HiRISE camera that can be modeled 
in the commercially available photogrammetry system SOCET 
SET. Photogrammetric processing of the transformed images is 
conducted using SOCET SET; the DEM is then generated based 
on the output results (Kirk, et al., 2007). However, in order to 
reach the best achievable mapping accuracy, inconsistencies 
between HiRISE stereo pairs must be removed based on the 
rigorous sensor model. Subsequently, this paper proposes a 
bundle adjustment to remove such inconsistencies using the 
rigorous HiRISE sensor model. Instead of using the commercial 
photogrammetric software used in the method described above, 
we are using our own code to incorporate the rigorous sensor 
model. Therefore, our results are free of errors caused by 
topography variation and can achieve the best level of accuracy 
can be reached. 
999