The dependence of the method on reliable visual tracking cannot be understated. During the research, a good deal of attention was paid to obtaining tracked landmarks which were free of outliers, and yet covered as many instances of the same visual features as possible. Achieving success in larger environments, and with lower sampling densities, will depend to a large extent, on how well tracked landmarks characterise the underlying visual features. Furthermore, the computational complexity of the current method is such that it is the most time-consuming aspect of the method. Indeed, this was one of the most challenging aspects of the research. Future work would include proposing alternative methods for tracking the landmark candidates. This would include methods for selecting appropriate thresholds and perhaps also incorporate reconstruction error, which was not considered in this context.