I created the below temporal Web map of the British and Dutch slaving voyages by converting the ArcMap GIS file (MXD file) into a KMZ file (a compressed KML file) using the Map to KML Tool found with the other Conversion Tools. GoogleEarth and other Web mapping applications use KML (Keyhole Markup Language) to render point, line, and other types of features. That KMZ file therefore includes not only the features and their attributes but the way I symbolized and otherwise configured them as layers in ArcMap.
Next, I opened the KMZ file with GoogleEarth and configured the time slider settings and symbols to suit GoogleEarth, a rather different type of display than ArcMap. Then I saved the reconfigured layer as one of My Places in GoogleEarth as well as, by right clicking the layer folder, as a new KMZ file. I uploaded that KMZ file to a website that I created on GoogleSites, for free yet again, storing it in a page created with the File Cabinet Template and setting its permissions to allow public access. Then I went back to Google Earth and opened the Embed KML Gadget, configuring the various options such as dimensions and entering the URL for the KMX file stored on my GoogleSite.
Next, I opened the KMZ file with GoogleEarth and configured the time slider settings and symbols to suit GoogleEarth, a rather different type of display than ArcMap. Then I saved the reconfigured layer as one of My Places in GoogleEarth as well as, by right clicking the layer folder, as a new KMZ file. I uploaded that KMZ file to a website that I created on GoogleSites, for free yet again, storing it in a page created with the File Cabinet Template and setting its permissions to allow public access. Then I went back to Google Earth and opened the Embed KML Gadget, configuring the various options such as dimensions and entering the URL for the KMX file stored on my GoogleSite.
The result is a fully functional temporal GIS of the British and Dutch slaving voyages of 1751-1795, first shared using ArcGIS Online. Selecting any of the daily position symbols opens a pop-up box with a link to the Web page for that voyage in the Trans-Atlantic Slave Trade Database. By adjusting the various controls of the time slider, users can view the entire period (1751-1795) or constrain it to a single decade, adjust how many months or years of symbols are visible at once, and move along the temporal sequence one step at a time or as a continous animation.
The control of the time slider, especially over the speed at which the sequence runs, is limited compared to using it in GoogleEarth. The KMZ file can, however, be downloaded and added to GoogleEarth running on a computer or added using the Add Network Link. Doing that will also allow users to access the individual layers for each voyage, the daily position points, and all the attributes as well as to resymbolize points, remove and add data, such as place markers for ports, and finally to save their work as a new KMZ file.
The free versions of GoogleEarth, ArcGIS Online, and GoogleMaps Engine Lite, of course, cannot do nearly as much as the ones you pay for: GoogleEarth Pro is $399 for an annual license; a paid subscription to ArcGIS Online is at $2,500 per year for the minimum of 5 users; and GoogleMaps Engine is "expensive."
The control of the time slider, especially over the speed at which the sequence runs, is limited compared to using it in GoogleEarth. The KMZ file can, however, be downloaded and added to GoogleEarth running on a computer or added using the Add Network Link. Doing that will also allow users to access the individual layers for each voyage, the daily position points, and all the attributes as well as to resymbolize points, remove and add data, such as place markers for ports, and finally to save their work as a new KMZ file.
The free versions of GoogleEarth, ArcGIS Online, and GoogleMaps Engine Lite, of course, cannot do nearly as much as the ones you pay for: GoogleEarth Pro is $399 for an annual license; a paid subscription to ArcGIS Online is at $2,500 per year for the minimum of 5 users; and GoogleMaps Engine is "expensive."
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