AMASC01 Circle Buffer Capture

The Circle Buffer Capture mode is intended for situations where the priority is not continuous all-night imaging, but capturing very fast transient events at the highest frame rate the camera can reliably deliver.

This software is based on CircularPiCam, a capture pipeline designed for high-speed event recording with RAM-based circular buffering and trigger-controlled clip saving.

Purpose

This mode has the opposite design goal compared to the standard Base Software Stack, which is built around continuous all-sky monitoring, long-term operation, and regular image generation.

Circle Buffer Capture focuses instead on:

• maximum frame rate
• short-event recording
• pre-trigger and post-trigger history
• fast trigger response

This makes it suitable for phenomena that happen too quickly for standard periodic all-sky imaging.

Note: This software was originally developed specifically for the AMASC01 platform and for monitoring the development of bolides and other very fast luminous events in the sky. At the same time, it is designed as a more universal capture system and can also be used with optics with a narrower field of view, with other camera configurations, or in application-specific trigger and recording setups. For more information about suitable configurations or possible adaptations, please do not hesitate to contact us for consultation.

Sensor Options

On request, the AMASC01 can be equipped with a Sony IMX296 sensor in either:

• monochrome variant
• color variant

The Sony IMX296 uses a global shutter and supports frame rates of up to 60 FPS, which is important for capturing very fast events without rolling-shutter distortion.

Circular Buffer Principle

The software continuously stores recent image data in a RAM-based circular buffer. This means the system always keeps the most recent seconds of recording in memory, even before any trigger occurs.

Circular buffer principle showing continuous frame rotation, trigger point, and clip export with preserved pre-trigger and post-trigger history.

When a trigger is received, the software saves:

• several seconds before the trigger
• the trigger moment itself
• several seconds after the trigger

This allows the user to record not only the event, but also what happened immediately before it.

Trigger Options

Several trigger methods can be used depending on the application:

• WebSocket trigger
• light-change trigger
• keyboard trigger
• GPIO signal trigger

These trigger modes allow the camera to react to external systems, sudden scene changes, or direct operator input.

Typical Use Cases

Circle Buffer Capture is useful for events that are brief, unpredictable, or scientifically interesting only when the full pre-event context is preserved.

Example use cases include:

• meteor and bolide events where the trajectory onset is important
• lightning and transient atmospheric discharges
• sudden optical flashes or short luminous phenomena
• laboratory or field experiments synchronized by GPIO trigger
• external instrument correlation, where another detector triggers optical recording
• diagnostics of fast mechanical or environmental events, where the state before the trigger matters

In all of these scenarios, the ability to preserve frames from before the event is often more valuable than continuous low-rate imaging.

Open-Source Availability

Note: This software is also open-source. If you are interested in this capture mode or want to discuss a custom configuration, please use the contact information in the About section.