Image mosaics of planetary surfaces are essential for both engineering and scientific tasks. A community focus has been aimed at maximizing the engineering value of mosaics, including adoption of the term “foundational” to describe the role mosaics play as datasets upon which other products can be reliably placed. Less work has been done to increase the intrinsic scientific integrity of image mosaics themselves, thus reducing their scientific value.

Image mosaics should be held to the same scientific standards of traceability as the science that they facilitate. All derived data should be traceable back to their source, all methods for the construction of the mosaic should be reported and known artifacts and other limitations of the product should be communicated. These standards have long been applied to the instruments that collect the data, and the science derived from image mosaics, but not to mosaic products themselves.

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I led the construction of the largest image ever made, a 5.0 m/px global mosaic of Mars using imagery acquired by the Context Camera (CTX) on the Mars Reconnaissance Orbiter (MRO). We constructed it using cutting-edge information-preserving techniques of non-destructive image processing that allow for full traceability of the final mosaic, allowing users to know where their data come from. This is critical for proper interpretation, instant access to the original data that comprise the mosaic, and efficiency while quality controlling the mosaic. Non-destructive processing is also considerably more efficient than traditional destructive processing, allowing us to create the mosaic without dependance on high-performance computing. More information about our mosaicking process can be found here, while more information about CTX itself can be found here.

To view the mosaic, please see the project's official site.

The beta version of the global CTX mosaic has been used over 120 times for scientific research, including the automated mapping of over 90 million impact craters.