Motivation and design
Maps are a central part of the way geologists communicate their understanding of the natural world. At their best, geological maps go beyond recording the type of rocks at a specific location to express hypotheses about the organization of rocks in time and space.
Lately, working geologists have been faced with an unappetizing choice: to stick with a time-consuming analog process even in the face of accelerating mapping demands and the need for digital outputs, or to fully commit to overly proscriptive digital processes which degrade mapping from an interpretive to a technical task.
Mapboard GIS is an iPad mapping system for drawing geospatial information into a spatial database. It works both in a standalone, field-ready mode and as a tethered client, with a paired desktop or laptop handling geospatial operations. It is designed to support intuitive editing and to make digitally composing geologic maps a quicker, more human-oriented process.
Drawing is an excellent geological mapping method because sketching allows quick capture of complex spatial patterns. "Stream digitizing" is available on other GIS platforms, and is reasonably effective when combined with accessories such as Wacom graphics tablets, but the editing tools are geared towards precision rather than fluidity.
Tablet-based computing enables new and richer capabilities for pen-based input previously unattainable in computing. Mapboard GIS fully utilizes the precision-capture capabilities of Apple's iPad platform to support painless drawing, erasing, and redrafting of linework. This reduces the digital hurdles to making a well-designed map that faithfully represents interpretations.
Balancing power and simplicity
Bringing in computers can add a lot of complexity to field workflows, and care must be taken not to overcomplicate the process or add new constraints. This is especially true when integrating capable but dense GIS software.
In addition to streamlined stylus tools, tablet devices (particularly the iPad platform) offer a stripped-down user interface that limits user-facing complexity. iPads, much like their predecessor smartphones, run in a single-app mode with only limited multitasking capabilities.
While openness and configurability are often prized computing features, the simplicity of a tablet platform is a major benefit when working in the field — a stripped-down digital process is less likely to intrude on the real-world task at hand. The user interface and editing tools of Mapboard GIS are simple enough not to intrude on users' field processes.
Another potential side benefit purposefully simple software is easier use in educational settings. We plan to explore this aspect further in the future.
One of the major hurdles to building a fully defined geologic map is topology, the part of the mapping process where boundaries are joined to fill space. In traditional GIS workflows, this process happens after all linework is added to digitized and finalized. Even with the quicker drawing tools provided by Mapboard GIS, this is a major technical obstacle, as it prevents seeing the output of your mapping until you have finished entering the data. Building a process where changes are reflected in topology as soon as they are entered, will make it much simpler to see the effects of changes in real time.
Mapboard GIS supports an innovative iterative mapping workflow. Its topological engine can solve the boundaries of map polygons in real time, showing the output of the mapping process as it is created. This also reduces the risk of propagating major topological errors and eliminates the "data cleaning" that has to be done before linework is closed and converted to polygons.
Field and tethered modes
Field mapping is an important workflow for geologists, but a large amount of map production happens back in the office. Both the core data-capture workflow and the topological capabilities of the Mapboard GIS can be powered either by an onboard GIS engine, or by a connection to a spatial engine running on a networked computer. Because desktop computers can run more powerful database software than tablets, this has benefits for speed, data security, and interoperability. Real-time updates can allow editing along other Mapboard GIS users and desktop GIS software.