Portable cloud & sky quality detector
The improved version of our previous PocketCloudWatcher. Measures clouds, sky quality, temperature, humidity, dew point and pressure, detects wind, has GPS location—and all of it accessible from the phone and the PC.
Not designed for permanent outdoor installation. Not rain resistant.
The PocketCW2 packs the full CloudWatcher sensor suite into a 71 × 71 × 27 mm enclosure: everything you need to know whether the sky is safe to observe.
IR sensor reads sky temperature and determines cloud cover in real time.
Measures sky brightness in mpsas. Dichroic UV/IR filter for accurate readings.
Ambient temperature and calculated dew point, essential for moisture risk assessment.
Relative humidity percentage, monitoring conditions that affect seeing and optics.
Barometric pressure monitoring for weather trend analysis.
Detects wind presence—a crude measurement, but enough to flag windy conditions.
Built-in GPS for location-aware reporting and logging.
Designed for observers who are always on the move—star parties, remote sites, travel—PocketCW2 gives you full observatory-grade sky monitoring without the installation.
Includes 2.4 GHz Wi-Fi, so your readings reach the phone and the PC without cables.
All of it accessible from the phone and the PC. Live readings, configurable alarms and watchdog alerts. Free app for iOS and Android.
Protocol support for Safety Monitor and Observing Conditions, either via http or file.
Set custom thresholds for every reading. Watchdog alerts if data stops updating. Battery level alarm included.
Charges and communicates via USB-C. Optional internal rechargeable LiPo battery for fully wireless field use.
71 × 71 × 27 mm, under 85 g. Fits in a jacket pocket. Take it to any observing site, any night.
Small enough to forget it's in your pocket, sharp enough not to miss a cloud rolling in. Set your alarms, close your eyes for five minutes at the eyepiece—PocketCW2 is still on watch.
PocketCW2 uses standard protocols so it slots into any automation workflow, on a laptop, over the network, or from your phone.
These are just a few examples: any ASCOM-Alpaca, INDI or INDIGO compatible software will work with the PocketCW2, not only the ones listed above.
Portable use only. The PocketCW2 is not to be permanently installed outside, and is not rain resistant.
If you are looking for a full feature sky weather conditions cloud detector that can be permanently installed outside, choose our CloudWatcher high precision and low-cost system for monitoring the sky conditions and measuring sky quality.
No need to install: download it, run it, configure, and delete it when you're done. See downloads.
Live sensor readings, configurable alarms and custom alert sounds, all from your phone or desktop.
A short animated introduction to what PocketCW2 does and why it matters.
K-factor optimisation tool now available.
New ASCOM observing conditions and safety monitor driver released.
New pocketCW2 configuration Windows application released—allows configuring K-factors, safety limits, wind…
New CloudWatcher and pocketCW data display software released.
The pocketCW2 is launched.
The pocketCW makes it to Sky & Telescope’s Hot Products list!
The pocketCW (the pocketCW2’s predecessor) is launched.
Curious about news relating to other products? Check out our latest product news page—you can also join our product news newsletter from there.
| Dimensions | 71 × 71 × 27 mm |
| Weight | < 85 g |
| Power | USB-C (also charges internal battery) |
| Battery | Internal rechargeable LiPo (optional) |
| Connectivity | Wi-Fi 2.4 GHz + USB-C |
| GPS | Built-in |
| Cloud detection | IR sensor |
| Sky quality | mpsas (with dichroic UV/IR filter) |
| Protocols | ASCOM-Alpaca, INDI, INDIGO |
| Scripting | Lua, built in |
| Sensors | IR, humidity, temperature, pressure, light, wind |
| Outdoor use | Not for permanent install—not rain resistant |
Launched in 2018, the first pocketCW went on to make Sky & Telescope's Hot Products list in 2019. PocketCW2 is its improved successor: same idea, more sensors, better connectivity.
Build your own integrations with Lunaticoastro devices. Every command travels over plain HTTP, USB or UDP—one protocol shared across the whole range, so what you learn on one device works on the next.
Explore SLP391 commands · 12 devices · try one from your browser
Every command the PocketCW2 understands, over HTTP, USB or UDP—one protocol shared across the whole range. For scripting and custom integrations.
Full documentation including first-steps guides for smartphone and computer setup.
Go to documentation →Windows software, ASCOM and USB drivers, firmware and the configuration tool.
Go to downloads →How-to guides, integration tutorials, software configuration and community resources.
Browse docs →