Monitoring Light

Quantifying light levels in a meaningful way is challenging. Recognising this, Pendoley Environmental has developed cutting edge light monitoring technology in-house at our Digital Horizon Imaging division.

Using this technology, we can:

  • Monitor the amount of light visible to wildlife at habitat adjacent to your facility;
  • Establish a benchmark of overall night sky brightness today, to monitor against future change following construction of your development;
  • Provide a real-time footprint of artificial light produced during construction of your development; and
  • Verify existing light sources meet manufacturer specifications and determine the effectiveness of management controls.

Determining the correct technology to apply for your light monitoring needs is dependent on the specific needs of your project:

Do you need to monitor the influence of light on wildlife in sensitive areas?

Technology: Sky42 Light Monitoring Cameras

Application: Our Sky42 technology uses a DSLR camera and fish-eye lens to take high-resolution, hemispherical photos of the whole night sky. These images capture all point sources of light and sky glow that are visible from the monitoring location on the full 360o horizon.

Features: Each Sky42 camera is combined with a custom built circuit board and contained within a weatherproof, rugged housing that allows it to be deployed at a remote site to capture imagery autonomously at set intervals (between sunset and sunrise), under extreme weather conditions of wind, rain, dust, sand etc.

Output: Capture imagery are processed using specialised software that quantifies the brightness of each pixel in the image, outputting a ‘heatmap’ of brightness. This allows us to determine the spatial distribution of all light in the sky (including sky glow), the source of light, and, following repeated surveys, how levels of light changes over time.

Do you need to monitor light across a wide area in realtime?

Technology: Wireless Sky Quality Meter Array

Application: A Sky Quality Meter (SQM) measures the brightness of the sky directly overhead. By placing a fixed array of SQMs in the the area within and surrounding your development site, you will be able to monitor the real-time brightness of your development and at nearby sensitive habitats.

Features: SQMs are lightweight (<1 kg), operate continuously for the life-time of the development using a solar panel and in-built battery, transmit data wirelessly via an in-built LoRa (long-range) WiFi module (up to distances of 10 km), and can be used almost anywhere there is an unobstructed view overhead. Transmitted data is stored on a designated server and made accessible via a client-specific login as an interpolated "heatmap" of brightness.

Output: SQMs output a single value indicating sky brightness overhead. We can look at how light changes at a single point over time, or we can use values from multiple monitoring locations to model the light between points and generate an interpolated “heatmap” of brightness that changes as updated measurements are received from each SQM.

Do you need to audit your current lighting against a specific standard or manufacturer specifications?

Technology: Spectroradiometer

Application: Our spectroradiometer is used to determine the spectral power distribution of an indivudal light source to determine its wavelength and relative amount of visible light emission. This information can also be used within a light audit to verify that it meets the manufacturer specifications.

Features: The spectroradiometer is a small portable instrument that measures the relative amount of visible light emissions at each wavelength between 400nm and 700nm, providing a spectral fingerprint for specific light types such as LED, high pressure sodium, metal halides etc. Results can be visualised in real-time using a connected laptop.

Output: A graph of relative light emissions at each wavelength across the visible spectrum allows specific light types to be identified and confirmed. Quantitative results include a measure of photometric (calibrated to the human eye) light in units of Lux.