Observatory Sky Monitor is a comprehensive solution for a permanently installed monitoring instrument at an observatory. It measures and reports the Sky brightness levels, Sky temperature and other derived parameters, as well as outdoor ambient conditions including the temperature, humidity, dew point and rain conditions.
The instrument installs simply and quickly on any flat surface using 2 (user supplied) screws. It does not require long data or USB cables. The reports are made via the integrated Wi-Fi, to any 2.4GHz access point within approximately 100m range (terrain dependent). It only requires a DC power supply (user supplied) to its 2 pin, IP68 rated connector. Thus a short wire run to the observatory is all that is required.
The instrument contains two dew/ice heaters to prevent formation on the Sky Brightness lens and the rain sensor.
Observatory Sky Monitor interfaces to ASCOM or its own native application via the Wi-Fi connection. It does not require complex IP or port settings, only a simple Access Point setup.
Features:
- Filtered Sky Brightness Measurement in MPAS2, NELM and Bortle
- Sky Temperature and Sky Delta to detects even smallest cloud whiffs
- Atmospheric Perceptible Water column in mm
- Ambient parameters such as Temperature, %RH and Dew Point
- Dew Point Alarm
- Wi-Fi Connectivity
- No data cables – only an inexpensive 2 wire power line
- ASCOM drivers for supported readings
- Native monitoring application for an all-encompassing data monitoring
- Integral dew/ice heaters
- IP68 rated device
- Simple installation
SQM Filtering Response is similar to that of other widely used instruments. Typical variance is roughly 0.010 MPAS2.
Observatory Sky Monitor Specifications
| 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 below 20 MPAS2 |
| Beamwidth (HWHM) | 13 | degrees |
| Update Rate | 5 sec typ. @ 19 MPAS2 | Slowest: 30 sec at 23 mpas |
| Filter | BG-39 | Similar to CM500 |
| Dew/Ice Heater | Included | |
| STM (Sky Temperature) | ||
| Range | -70 to 60 | degrees C |
| Resolution | 0.01 | degrees C |
| Noise | 0.01 | degrees C RMS |
| Beamwidth (HWHM) | 12 | degrees |
| Accuracy | TBD | degrees C |
| Update Rate | 1 | sec |
| Emissivity | 0.7 | set to typical Sky |
| PWV (Precipitable Water Vapor) | 0 to 20 | mm (reduced accy. Above 20mm) |
| Measured Ambient | ||
| Temperature | -20 to 70 | C |
| RH | 0 – 99.9 | % |
| DP | -20 to 70 | C |
| Wi-Fi | ||
| Protocol | 802.11 b/g/n | 2.4 GHz |
| RF Power | 100 | mW |
| Power Supply | ||
| Voltage | 10 to 24 | VDC |
| Supply Current | 1 | ADC |
| Connector | SP-13, 2 PIN | IP68 rated, Plug & Socket Provided |
| Rain Sensor | ||
| Dew/Ice Heater | Included | |
| Environmental and Water Ingress | ||
| Protection Level | IP-68 / NEMA 6P | |