International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B4, 2012 
XXII ISPRS Congress, 25 August - 01 September 2012, Melbourne, Australia 
301 
SYSTEMATIC BUNDLE ADJUSTMENT OF HRSC IMAGE DATA 
J. Bostelmann*, R. Schmidt, C. Hcipke 
Institute of Photogrammetry and Geoinformation (IPI) 
Leibniz Universität Hannover 
Nienburger Str. 1, D-30167 Hannover, Germany 
bostelmann@ipi.uni-hannover.de 
Commission IV, WG IV/7 
KEY WORDS: Extra-terrestrial, Mapping, Planetary, Matching, Bundle, Adjustment, Global, Analysis 
ABSTRACT: 
The European Mars Express mission was launched in June 2003 and sent into orbit around Mars. On board the orbiter is the German 
High Resolution Stereo Camera (HRSC). This multi-line sensor images the Martian surface with a resolution of up to 12m per pixel 
in three dimensions and provides RGB and infra-red color information. The usage of the stereoscopic image information for the 
improvement of the observed position and attitude information via bundle adjustment is important to derive high quality 3D surface 
models, color orthoimages and other data products. In many cases overlapping image strips of different orbits can be used to form 
photogrammetric blocks, thus allowing the simultaneous adjustment of the exterior orientation data. This reduces not only local, 
but also regional inconsistencies in the data. With the growing number of HRSC image strips in this ongoing mission, the size and 
complexity of potential blocks is increasing. Therefore, a workflow has been built up for the systematic improvement of the exterior 
orientation using single orbit strips and regional blocks. For a successful bundle adjustment of blocks using multiple image strips 
a sufficient number of tie points in the overlapping area is needed. The number of tie points depends mainly on the geometric and 
radiometric quality of the images. This is considered by detailed analysis of the tie point accuracy and distribution. The combination 
of methods for image pre-processing, tie point matching, bundle adjustment and evaluation of the results in an automated workflow 
allows for all HRSC images a global assessment of the quality and a systematic selection of data for larger blocks. 
1 INTRODUCTION 
The Mars Express mission conducted by the European Space 
Agency (ESA) is investigating the Red Planet since January 2004. 
One of the scientific instruments on board the orbiter is the High 
Resolution Stereo Camera (HRSC). This multi-line stereo scan 
ner is equipped with 5 panchromatic and 4 color charge-coupled 
device (CCD) line detectors, each with 5176 pixels. The configu 
ration of the sensor lines on the focal plane of the camera allows 
a stereoscopic image acquisition of the Martian surface (Neukum 
et al., 2004). Until March 2012 the HRSC has orbited the planet 
10,500 times aiming at a global coverage of image data. 
By simultaneously reading out (up to) nine CCD sensor lines, 
while the camera points at Mars when reaching the periapsis of 
the highly elliptical orbit, long image strips are created. Because 
of the different viewing angles in the images of these strips, it 
is possible to obtain stereo color data, with a resolution of up to 
12m per pixel, depending on the flying height. 
To use the HRSC image data for the derivation of digital terrain 
models (DTMs) or orthoimages the knowledge about the position 
and attitude of the camera is essential. The position is observed 
via Doppler measurements, and star trackers control the attitude 
of the camera. The combination of these observations is called 
the nominal exterior orientation of the camera. In many cases 
the quality of the exterior orientation is not accurate enough for a 
precise photogrammetric point determination. Therefore, a large 
number of automatically determined tie points is used in a bundle 
adjustment to improve the accuracy of the exterior orientation and 
to exploit the full potential of the stereo image data. 
In many cases overlapping image strips of different orbits can be 
used to form photogrammetric blocks (see Fig. 1), thus allow 
ing a more consistent adjustment of the exterior orientation data. 
* Corresponding author 
With the growing number of HRSC image strips in this ongoing 
mission, the size and complexity of potential blocks is increasing 
and a detailed knowledge about the photogrammetric capability 
of the HRSC data is needed to assure geometrically stable blocks. 
Figure 1: Color coded MOLA DTM with footprints of 21 HRSC 
nadir channel images constituting a photogrammetric block 
We have developed a workflow for a systematic bundle adjust 
ment of the HRSC image data. This workflow for single orbit 
strips is described in chapter 2. In chapter 3 the extension of this 
method for multi orbit blocks is described. Results including a