Synopsis of Topic
We will recap the information covered on Day 1 with an emphasis on realizing that there are many ways to undertake topographic surveys to support change detection analyses and we are not advocating any single technique. Instead, we are trying to equip you to make an informed and appropriate decision based on your circumstances about how to proceed through the process of geomorphic change detection. Regardless of techniques, robust, recoverable and consistent control networks between surveys are critical, as are consistency in coordinate systems, datums, geoid models and projections. When constructing DEMs for change detection, the concepts of orthogonality, concurrency and dimensional divisibility are instrumental in doing raster based change detection. Ultimately, Day 1 is the due diligence you need to undertake in order to explore interesting applications and make reasonable interpretations of your repeat topographic surveys with some confidence. We will continue with this theme in Day 2, with a focus on error modelling to facilitate differentiating the signal we’re after from noise.
Why we’re Covering it
- To make sure that workshop participants are confident in understanding the basics of change detection and surveying principles, before doing more sophisticated error analyses & change detection (Day 2) or using these techniques in any sort of interpretative fashion (Day 3).