Thursday, October 27, 2005

The Data Monitor comes to Pocket GTViewer

The GTI Data Monitor is now included in the soon to be released Pocket GTViewer 5.0. The “Mini” Data Monitor found in Pocket GTViewer is a subset of the Data Monitors found in GTViewer and GTVx; however, it provides specific functionality that works best in the device environment while respecting the limited resources and performance of today’s Windows CE devices (Pocket PC/Windows Mobile/CE.NET).

For those not familiar with the GTI Data Monitor, see the previous posting on what it has been used for on the desktop. In short, the Data Monitor provides an efficient mechanism for quickly showing data that is not necessarily part of the GIS data and is temporary in nature or changes frequently. While session graphics (redlines) can usually be used to display the same information as the Data Monitor, redlines are meant to be stored and shared and the overhead associated with these characteristics makes them more resource demanding when dealing with a large number of constantly changing items. The idea behind the Data Monitor was the need for a tool to efficiently track a large number of trucks with GPS receivers in real-time. Hundreds of trucks, all of which could be in motion, required a dynamic framework more efficient than what redlines alone could provide. As it turns out, the Data Monitor is just as useful for information other than vehicle locations, such as lightning strikes, ticket locations, and many others.

The “Mini” Data Monitor found in Pocket GTViewer is a scaled down version of what is found in GTViewer and GTVx, but it provides the essential qualities that make the Data Monitor useful. In the example below, each Red star is a ticket location loaded from a file containing a list of ticket information:

Zooming in closer shows a more detailed landbase (from the GIS data) and dynamic labels on the Data Monitor items:

Data Monitor symbols can have their display size be zoom-independent as they are in the above two screenshots (always the same size regardless of the zoom level) or they can be scale-dependent and get larger as you zoom in to them.

The screenshots below show how items can be changed. An item’s symbol, rotation, size, color, label, and geographic position can all be changed with minimal overhead:

Just like the desktop Data Monitors, data can be associated with an item. Using the tap-and-hold gesture on one of the items, an Attribute Info dialog will appear showing detailed information:

The addition of the Data Monitor to Pocket GTViewer 5.0 expands the possibilities for application development. The Data Monitor provides a dynamic means of utilizing data that is not necessarily from your GIS. Pocket GTViewer has long been a powerful platform for GIS application development, and with the Data Monitor it is even better.

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