The more of these solar antennas I see on light poles and the more I read, the more convinced I am that they are part of the SFPark smart parking pilot project. They seem to be sprouting up as we get closer to launch and they are generally in the same areas as where SFPark is bring tested and some old articles seem to confirm they are part of the system.
According to a June 2010 SF Streets Blog article:
The [white street] sensors are made by Streetline Inc, a vendor with contracts in San Francisco, Los Angeles and several other cities. Surface-mounted sensors resemble the Bott’s dots between lanes on a freeway, while the embedded sensors are flush with the pavement. The sensors detect ferrous metal within a five-foot radius and therefore can detect both stationary and moving vehicles within that range. They will also communicate wirelessly with new parking meters, which will be installed within the next month or two.
The sensors network wirelessly with radio equipment installed in single-space or multi-space meters, a combination that allows parking managers to obtain real-time parking-space occupancy readings, payment activity, and meter functionality.
The meters and sensors link to a transmission box, typically mounted on light poles every few blocks, which transmits data to the company’s servers. Every piece of equipment in the network is a peer, so that interference disrupting the connection between two units can be bypassed to another to ensure data is still being collected. Streetline boasts 99.9% effectiveness, better than cellular networks.
Its interesting to me how low most of these new antennas are. I assume its for technical (i.e. power/range) reasons but they don’t seem like they’d survive a night in a rougher city (New York for example).