The Signal Heatmap is turned off by default. You can turn it on in ‘Map Layers’ settings.
The Signal Heatmap is a map layer that visualizes the intensity of FOAM tokens staked to the FOAM map in signals. A signal has 2 components – token value and radius. The heatmap shows the values and radii of all the signals in a geographic area.
The color of the heatmap shows the value of FOAM tokens. Blue is the lowest value and yellow is the highest value.
The area covered by the heatmap is calculated by taking the radius of each signal located there. The larger the radius of a signal, the larger the area of the heatmap.
The following image illustrates the difference between token value and radius on the heatmap:
The smaller signal in Davis, California has 4000 FOAM staked and a radius of 2 km, resulting in a yellow color but small heatmap area.
The larger signal in Sacramento, California has 50 FOAM staked and a radius of 15 km, resulting in a blue color and larger heatmap area.
For more information see:
What is a signal?
What are map layers?