S.W. Hobbs

Marsobot: design and performance characterization of a low-cost, ground-based multispectral camera on an open source rover

ABSTRACT Open source, low cost sensors, and robotic systems have developed to the point of being able to produce meaningful, repeatable results in real-life applications. We developed a low-cost, open source multispectral camera mounted on a small custom-built robotic rover. We compared the performance of our camera with a commercial multispectral camera and a laboratory spectrometer using minerals commonly found on Mars that exhibited different reflectance values in visible and near-infrared wavelengths. Our camera performed favourably when compared to the commercial instruments. It is a very cost effective solution for operating in extreme situations, where damage to instruments is possible. Our total system of rover and sensor would, therefore, be very useful for operating in delicate and inaccessible environments where damage to the area under investigation and to human observers is of concern.

Evaluating low-cost spectrometer designs for utility in reflectance and transmittance applications

ABSTRACT Recent advances in low-cost microprocessors and sensors have allowed for the development of low-cost spectrometers for public experimentation and education outreach. In the context of the present paper and other recent research, low-cost spectrometers are important remote sensing instruments for numerous applications in citizen science and education. We built five spectrometer designs then tested them for absorption using concentrations of fluids and reflectance using colour swatches and minerals found on Mars as well as other materials possessing a high near infra-red (NIR) reflectance. These results were then compared with a laboratory grade spectrometer. We found that while all spectrometers produced meaningful results during the fluid concentration tests, there were considerable differences in accuracies between home-made instruments during the reflectance testing. Two spectrometer designs were identified that produced useful results for a range of low-cost scientific applications.

Testing ground-based robotics as remote-sensing platforms for Structure from Motion – implications for planetary science

ABSTRACT We assessed robotic performance by performing Structure from Motion (SfM) mapping surveys of a small gully in New South Wales, Australia, using two rovers of different sizes that each captured photographic images from a high-resolution, 12 megapixel (MP) camera and a low-resolution (<1 MP) camera. Results from these trials were compared with a simulated unmanned aerial vehicle (UAV) SfM survey of the same gully feature using the high-resolution camera on a boom pole. We conducted this in order to determine whether small, ground-based vehicles would be suitable remote-sensing platforms for collecting this data where UAV operations would be impractical or impossible. Accuracy of the resulting point clouds and the time taken to complete the surveys were used as the key metrics to assess the performance of the respective methods. The high-resolution camera surveys produced digital elevation models (DEMs) that corresponded closely to the control points surveyed using Real Time Kinematic (RTK) global positioning system (GPS) technology, although the robotic surveys took longer to complete. Additionally, camera resolution and height above ground were the major factors when determining the success of generating SfM data. We found that despite these limitations, ground-based vehicles are capable of generating point clouds accurate enough to be used to investigate small-scale geomorphology.