I wasn’t completely happy with the my last Google Maps/Weather Radar mashup. Two things I discovered; that Google Maps doesn’t update a KML loaded from the search function, and that the radar locations weren’t clear enough.
The later, radar visibility, was fairly east to correct. I added the transmitter points to the KML, and added a 10% magenta overprint to show the 200km range of the radar.
The first, I discovered that the Google Maps API is not completely in line with the KML reference, as that it doesn’t update images or dynamic content except with very specific controls. Google Earth KML’s have a <refreshMode> tag that allows users to declare expiration of data base on user behavior, a time delay, or expiration date and time. As far as I can tell, only the latter, onExpire, is supported by Google Maps. The options for using onExpire are based on either HTTP header settings, or setting an expiry time in the kml. The HTTP header settings are beyond my control with the hosting I use, and this left me with calculating a date/time stamp to be embedded in the KML.