According to a recent press release by the national government, a sensor registry is being worked on. Too bad they the actual register itself cannot be currently accessed.
In any case, the stated purpose of this first attempt at a national registry for sensors used in urban public spaces is to enhance public transparency, and avoid doubles and promote reuse. This second wij to me sounds a bit tricky, as it may lead to ‘mission creep’ with additional usage scenarios being stacked onto a single initial purpose.
Amsterdam municipality already has such a registry, albeit incomplete.