Cluster Map
A node can belong to a cluster as a primary member, or as an overlap contributor
whose field of view extends into a neighboring cluster's territory too (see
allsky_node_cluster.isoverlap). Pick a cluster to see its footprint, or leave
it on "All clusters" to see which nodes participate in more than one.
not in a cluster
in one cluster
in more than one cluster (overlap)
other nodes
primary member
overlap member