using Regions, network links, time span in kml, but GE loads up entire file on startup - kml

Question

I have global data for fires around the world covering three days. Projecting the entire data into one kml ends up in huge kml. I tried to break up the data in to smaller regions and also smaller time intervals.
So I have hundreds of regions covering the whole globe and data for each of these regions is divided into 6 kmls (time span of 12 hours in each) to cover 3 days.
Th problem is that even after dividing the global data into smaller chunks, once I load the master file, GE wants to load the entire data and becomes too slow. Could there be a better way of doing this or maybe highlight what I might be doing wrong?
the overview of my kml files is as follows:
the master kml :
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
<Document>
<Region>
<LatLonAltBox>
<north>90</north>
<south>-90</south>
<east>360</east>
<west>0</west>
</LatLonAltBox>
<Lod>
<minLodPixels>128</minLodPixels>
<maxLodPixels>1024 </maxLodPixels>
</Lod>
</Region>
<NetworkLink>
<name> Region NHAf</name>
<TimeSpan>
<begin>2011-06-01T00:30:00Z</begin>
<end>2011-06-04T00:30:00Z</end>
</TimeSpan>
<Region>
<LatLonAltBox>
<north>30</north>
<south>0</south>
<east>60</east>
<west>-30</west>
</LatLonAltBox>
<Lod>
<minLodPixels>128</minLodPixels>
<maxLodPixels>1024 </maxLodPixels>
</Lod>
</Region>
<Link>
<href>NHAf_base.kml</href>
<viewRefreshMode>onRegion</viewRefreshMode>
</Link>
</NetworkLink>
...
//more network links for other regions
</Document></kml>
This network links for different regions are further linked to sub-regions and the whole time span is also divided into smaller kmls :
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
<Document>
<Region>
<LatLonAltBox>
<north>30</north>
<south>0</south>
<east>60</east>
<west>-30</west>
</LatLonAltBox>
<Lod>
<minLodPixels>128</minLodPixels>
<maxLodPixels>1024 </maxLodPixels>
</Lod>
</Region>
<Folder>
<name>NHAf 1 0050</name>
<NetworkLink>
<name> Region 1 resolution 0050</name>
<TimeSpan>
<begin>2011-06-01T00:30:00Z</begin>
<end>2011-06-01T12:30:59Z</end>
</TimeSpan>
<Region>
<LatLonAltBox>
<north>30</north>
<south>10</south>
<east>-10</east>
<west>-30</west>
</LatLonAltBox>
<Lod>
<minLodPixels>128</minLodPixels>
<maxLodPixels>1024 </maxLodPixels>
</Lod>
</Region>
<Link>
<href>NHAf_1_hr01_frpfire_20110601_1130_0050_1.kml</href>
<viewRefreshMode>onRegion</viewRefreshMode>
</Link>
</NetworkLink></Folder>
<Folder>
<name>NHAf 1 0050</name>
<NetworkLink>
<name> Region 1 resolution 0050</name>
<TimeSpan>
<begin>2011-06-01T13:30:00Z</begin>
<end>2011-06-01T23:30:59Z</end>
</TimeSpan>
<Region>
<LatLonAltBox>
<north>30</north>
<south>10</south>
<east>-10</east>
<west>-30</west>
</LatLonAltBox>
<Lod>
<minLodPixels>128</minLodPixels>
<maxLodPixels>1024 </maxLodPixels>
</Lod>
</Region>
<Link>
<href>NHAf_1_hr01_frpfire_20110601_2330_0050_1.kml</href>
<viewRefreshMode>onRegion</viewRefreshMode>
</Link>
</NetworkLink></Folder>
...
//more network links till end of time step
//more network links with different sub-regions
</Documents>
</kml>

Answer 1

If you have multiple time periods split into multiple KML files then you can preselect the default time loaded at startup with the KML extension <gx:TimeSpan> in the root Document element of the KML file. This initializes the time slider for this time interval. For it to work, you must add a Camera or a LookAt element with a <gx:TimeSpan>.
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2"
xmlns:gx="http://www.google.com/kml/ext/2.2">
<Document>
<LookAt>
<gx:TimeSpan>
<begin>2011-06-01T13:30:00Z</begin>
<end>2011-06-01T23:30:59Z</end>
</gx:TimeSpan>
<longitude>...</longitude>
<latitude>...</latitude>
<altitude>...</altitude>
<heading>...</heading>
<tilt>...</tilt>
<range>...</range>
</LookAt>
...
You can add the TimeSpan to your KML in Google Earth with these steps:
Orient the view you want to startup with
Right-mouse click the root KML element and select Properties
Click View tab
Click 'Snapshot current view'
Select/edit the start and end time you want start with
Click OK
Reference: https://developers.google.com/kml/documentation/kmlreference#gxtimespan