Sky Quality Monitor

The Sky Quality Meter (SQM-LE) from Unihedron measures the darkness of the night sky and provides readings of magnitudes per square arc second. This information is displayed on the WEATHERSTATION GUI in the lower right corner (this is a snapshot from daytime):

The ENV TCS subsystem accesses the SQM-LE directly via the IP address/port: 192.168.18.42 / 10001. This is configured in the etc/env.conf file:

SQMIP            string  192.168.18.42   # Sky Quality Monitor ip
SQMPort          int     10001           # Sky Quality Monitor port

It is mounted inside the LBT structure at level 9 at the rear (south) end. It is on the outside of the vent door rails about midway. It views the sky only when the doors are opened. An Ethernet cable connects this device to a switch inside the porch door.

See the following docs for more info:

• Environmental Systems at the LBTO, Weather, All-Sky and Sky Quality CAN document - see section 10 for details
• Sky Quality Meter - SQM-LE User Manual
• As noted in the document, the SQM can handle only one TCP connection at a time.
  It should not be run on the old weather PCs anymore, or the ENV subsystem will not have access to the data.

History

The SQM was initially setup to be separate from the weather station partly to have a separate display on a different monitor. Joe Kraus wrote a simple windows GUI for this (below). This is how it was displayed before.

This was controlled by the TO's and used the middle large display.

The SQM application ran on the ENV , not weather windows pc. Part of this was to have a hot spare since both pc's had the same software. Once the DIMM showed up, this was not so useful.

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-- %USERSIG{JoeKraus - 2014-03-19}%