COMING SOON: Sky Quality & Temperature Meter

Sky Quality and Temperature Meter (SQTM) is a versatile observing session aid. Its graphic OLED display shows and charts a multitude of parameters relevant to sky observation. It can be used as a standalone instrument, or interface to ASCOM or its own native application via the USB or Wi-Fi connection (not required for stand-alone operation). Its integral rechargeable Lithium Polymer battery offers 8 hours of operation on a single charge.

The instrument includes a removable silicone grip for in field drop protection, with integral 45 °, collapsible stand.

A simple user interface allows users to scroll thru a number of display screens that best support your needs. There are 13 display screens for user to select from, using a simple one button user interface:


  • Filtered Sky Brightness Measurement in MPAS2, NELM, Bortle and Photons/cm2/sec
  • Sky Temperature and Sky Delta to detects even smallest cloud whiffs
  • Sky Temperature standard deviation display to gage sky stability
  • Atmospheric Perceptible Water column in mm
  • Ambient parameters such as Temperature, %RH and Dew Point
  • Dew Point Alarm
  • USB and Wi-Fi Connectivity
  • ASCOM drivers for supported readings
  • Native monitoring application for all encompassing data monitoring

The SQM sensor has an integral optical filter. Its filtering response is similar to that of other widely used instruments. Typical result variance is only about 0.010 MPAS2.  

SQM (Sky Brightness)    
Range 7.5 to 23+ Mag per Arc sec2 (MPAS2)
Resolution 0.001 Mag per Arc sec2 (MPAS2)
Noise (typ) 0.003 Mag per Arc sec2 rms below 20 MPAS2
Beamwidth (HWHM) 13 degrees
Update Rate 5 sec typ. @ 19 MPAS2 Slowest: 60 sec at 23 (MPAS2)
Filter BG-39 Similar to CM500 response
STM (Sky Temperature)    
Range -70 to 60 degrees C
Resolution 0.01 degrees C
Noise 0.01 degrees C RMS
Beamwidth (HWHM) 5 degrees
Accuracy TBD degrees C
Update Rate 1 sec
Emissivity 0.7 set to typical clear sky
PWV (Precipitable Water Vapor) 0 to 20 mm (reduced accy. Above 20mm)
Measured Ambient    
Temperature -20 to 70 degrees C
RH 0 to 99.9 %
DP -20 to 70 degrees C
Type OLED Blue/Yellow
Resolution 128 x 64 pixels
Protocol 802.11 b/g/n 2.4 GHz
RF Power 100 mW
Protocol USB 2.0  
Connector Micro B  
Type LiPo Rechargeable
Battery  Life 8 hours