Using a hemispherical mirror for an all-sky thermal camera system is a clever approach to achieve a 360° field of view. Here’s how it typically works:
- Setup: The thermal camera is positioned to look downward at the hemispherical mirror. The mirror reflects the entire sky into the camera’s lens, allowing it to capture a full view of the sky.
- Advantages:
- This setup is cost-effective compared to using ultra-wide-angle lenses.
- It provides a compact design for capturing a large field of view.
- The mirror can be made from materials that are durable and weather-resistant, suitable for outdoor use.
- Considerations:
- The quality of the mirror’s surface is crucial for accurate imaging. Any imperfections can distort the reflected image.
- Calibration is necessary to correct for distortions introduced by the mirror’s curvature.
- The thermal camera’s sensitivity and resolution should match the requirements of your application, such as cloud tracking or atmospheric studies.
For your all-sky thermal camera system, here are some recommendations for both the hemispherical mirror and the thermal camera:
Hemispherical Mirror
- Material: Look for a high-quality, polished metal or coated glass mirror. These materials ensure good reflectivity and durability.
- Size: The size of the mirror depends on your camera’s field of view. A larger mirror provides a wider reflection but requires precise alignment.
- Vendors: Companies like Edmund Optics or Thorlabs offer a range of optical mirrors that could work for your setup. You might also explore DIY options using polished stainless steel or acrylic domes.
Thermal Camera
- FLIR E8-XT: This camera offers a high resolution (320 x 240 pixels) and Wi-Fi connectivity, making it suitable for capturing detailed thermal images.
- Bosch GTC 600 C: A robust option with a wide temperature range (-20°C to +600°C) and excellent thermal resolution.
- Trotec IC300: Known for its real-time display and high sensitivity (0.05°C), this camera is ideal for precise thermal imaging.
Considerations
- Ensure the camera’s resolution and sensitivity match your requirements for sky observation.
- The mirror and camera should be compatible in terms of field of view and alignment.