All-Sky Camera & Cloud Detection

An all-sky camera answers the question a forecast can’t: what does the sky over the rig look like right now? With one connected, ARIS detects clouds live and paints them where they matter — on the Plan sky chart, over your actual targets — and certifies whether the sky is genuinely clear or quietly overcast.

Bringing a camera to ARIS

There are two paths, depending on where you are starting from.

You already run an all-sky camera

If you have an all-sky setup capturing frames tonight, ARIS plugs into it. Install the ARIS companion service on the machine that runs your camera — the rig’s own computer or a separate one — and it analyzes the frames your existing software is already producing and publishes sky intelligence to your rigs. Your current capture stack, keograms, and time-lapses keep working untouched.

You are starting fresh

Any all-sky camera with a decent fisheye lens will do the job — a small astronomy camera and a wide lens in a weatherproof housing is the common recipe. Attach it to the rig’s own computer, or give it a dedicated Raspberry Pi.

Today the camera runs under one of the popular open-source all-sky capture packages with the ARIS companion alongside. Direct raw-camera support — where ARIS drives the camera itself, with nothing else to install — is rolling out.

What you get

Clouds on your sky chart

Cloud detection is rendered on the Plan view in true altitude and azimuth: ARIS fits your camera’s actual lens projection, so a cloud bank in the western sky lands over the western targets on the chart. You see at a glance which targets are clouded out and which side of the sky is still open, instead of squinting at a fisheye image and doing the mapping in your head.

Absolute sky state

Frame-to-frame comparison catches moving clouds but misses the failure mode that ruins nights: a uniform cloud sheet that parks over the site and stops changing. ARIS keeps a photometric clear-sky reference and certifies the current sky against it, producing an absolute verdict — clear or overcast — that catches even a featureless gray lid. The verdict appears on the AllSky tile, and the Assistant can quote it when you ask about the sky.

It knows what a cloud is not

• Trees and buildings around your horizon are masked out automatically — a pine tree never reads as a permanent cloud in the south.
• The Moon is handled explicitly, so a bright moonlit region doesn’t register as cloud.
• Aircraft and satellites are rejected as transients — a trail crossing the frame is not weather.

The mask above is a real one, learned automatically from this camera’s own frames. On this site the camera sees about 41% true sky — and that number is exactly what cloud detection, sky-state certification, and sky-quality readings are computed against. No hand-drawn horizon polygons.

Zero-configuration discovery

ARIS finds the camera’s companion by name on the network, falls back to its last-known address, and as a last resort sweeps the local subnet. You never assign a static IP, reserve a DHCP address, or touch your router — and the camera survives address changes without reconfiguration.

Where it appears

• Plan screen — the cloud overlay renders as a layer on the sky chart, over your targets, in true alt/az.
• AllSky tile — the live all-sky view itself. When the absolute sky-state verdict is overcast, the tile carries a veil and a chip saying so, so a gray lid is called out instead of quietly looking like a dark sky.
• Assistant — ask the Assistant about the sky and it quotes the live verdict alongside the forecast.

Cloud detection and the weather forecast are complementary: the forecast plans the hours ahead, the all-sky camera reports what is actually overhead right now.

Caution

Cloud detection is planning and awareness, not sequence control. A running sequence does not auto-pause on sky state alone — condition-based pausing is Guardian night mode (opt-in), which corroborates sky state with guiding evidence before holding your subs. Also note that twilight can currently read as overcast while the sky brightens; a dusk/dawn gate is coming.

Requirements

• An all-sky camera producing frames, with the ARIS companion service installed on the machine that runs it.
• The companion and your rigs on the same local network.
• Cloud detection works at night; the absolute sky-state verdict needs a clear-sky reference, which the companion builds from your own site’s clear nights.

The overlay and sky state appear on ARIS rig computers; NINA-based rigs do not consume all-sky data yet (see NINA Integration).