# Design of low-cost, compact and weather-proof whole sky imagers for high-dynamic-range captures

## TL;DR

This paper introduces two innovative, low-cost, weather-proof sky imagers designed for high-dynamic-range captures, suitable for hot and humid climates, eliminating mechanical sun blockers by using HDRI techniques.

## Contribution

Development of two new weather-resistant sky imaging systems that operate effectively in tropical climates without mechanical sun blockers, utilizing HDRI technology.

## Key findings

- Both devices operate reliably in Singapore's climate.
- The systems successfully capture high-dynamic-range sky images.
- Elimination of mechanical sun blockers simplifies design and reduces costs.

## Abstract

Ground-based whole sky imagers are popular for monitoring cloud formations, which is necessary for various applications. We present two new Wide Angle High-Resolution Sky Imaging System (WAHRSIS) models, which were designed especially to withstand the hot and humid climate of Singapore. The first uses a fully sealed casing, whose interior temperature is regulated using a Peltier cooler. The second features a double roof design with ventilation grids on the sides, allowing the outside air to flow through the device. Measurements of temperature inside these two devices show their ability to operate in Singapore weather conditions. Unlike our original WAHRSIS model, neither uses a mechanical sun blocker to prevent the direct sunlight from reaching the camera; instead they rely on high-dynamic-range imaging (HDRI) techniques to reduce the glare from the sun.