View allAll Photos Tagged utc
27/11/2015
UTC RECIFE
EXPERIÊNCIA: MAPA AFETIVO RECIFE
NA FOTO Felipe Lavignatti, do Liquid Media Lab (SP)
FOTO: SILVIA RODRIGUES
There's a lot going on in this photo:
- The two 1U racks in the top left are autosensing fault switches connected to two outputs from the equipment that generates UTC(CH) in the basement clock vault. The top switch is for the 10MHz signal and the lower one is for the PPS pulses.
Each switch has inputs from two independent micro phase steppers that are steered to UTC(CH.P). Each stepper is connected to an independent atomic clock: normally channel A is the hydrogen maser while channel B is an HP 5071A.
- Below it is a Stanford Research Systems time interval counter. The yellow BNC cable is UTC(CH) from the clock vault. The blue BNC cable is connected to the commercial Meinberg LANTIME M600 GPS receiver in the top-right of the photo. The TIC shows the time difference in picoseconds; the two are within ~77.5 nanoseconds. During the time I observed it the value remained within a few hundred picoseconds. Perhaps they didn't correct for cable delay somewhere on the M600?
- Below the SRS TIC are three IRIG-B time code generators. These are connected to various equipment, such as the public NTP servers maintained in a different building.
- The Ashtech geodetic GPS receiver is in the blue foam-lined section of the rack. Evidently the thermal regulation in the Ashtech failed some time ago so they just put it in the foam box. It's more stable now than it used to be.