Our “A Brief Intro to AM0 Spectrum” is available on YouTube for a shorter explanation of the AM0 spectrum. Read on for those wanting extra information on the AM0 spectrum and additional resources.
What is the AM0 Spectrum?
Earlier, we described how a 5800 K black body can closely approximate the sun’s emission spectrum. This radiation travels 150 million kilometres and arrives in Earth’s orbit. Because it has travelled through the vacuum of space, there are no particles to absorb or scatter the light.
What is the air mass coefficient of the AM0 Spectrum?
To answer that, we first must answer: how much atmosphere has the light travelled through?
The answer, in this case, is none—zero. As you can see from the image above, the AM0 spectrum occurs outside of the Earth’s atmosphere. After that, the spectrum is no longer classified as AM0. In other words, there’s been no atmospheric transmission whatsoever when we look at the AM0 spectrum.
The following graph highlights the difference between AM0 and AM1.5 and the effects of the atmosphere on the spectrum. It is worth noting that these reference spectrums are one of the Class A standards, spectral match, on which solar simulators are measured (we will learn more about that in a future chapter!).
When we look over the two spectrums from above, it is no surprise there are differences between the AM0 and AM1.5 spectra. There is substantially more movement in the variation of the AM1.5G spectrum (Blue line). When integrating the entire energy under the curve, these dips and hills translate into a measurable power difference. The output from the AM0 spectrum is measured at (134.8 mW/cm2) than the AM1.5 spectra (100 mW/cm2). This 34.8 mW/cm2 reduction in output is due to the atmospheric effects on the light passing through, as discussed in the prior chapter. The important question is when the 34.8 mW/cm2 matters.
AM0 and Aerospace applications
As mentioned in our previous chapter (What is Air Mass), the AM0 spectrum is a commonly used standard, specifically in the Aerospace field. It is so widely used in the industry we have written several articles:
- Aerospace PV: How Solar Simulators Enhance Aerospace Photovoltaic Testing. It covers the AM0 spectrum and highlights the critical criteria for choosing a solar simulator for Aerospace.
- Aerospace Materials Testing: How Solar Simulators Enhance Spacecraft Ground Testing. This article dives into how the UV and IR spectrums of AM0 play a critical role in the integrity of spacecraft and the importance of ground testing.
- Aerospace Sensors Testing: How Solar Simulators Enhance Aerospace Sensor Testing. Explores testing the various sensors used to guide spacecraft or gather data.
For now, all we need to understand is how important the AM0 spectrum is for space exploration, low-orbit CubeSats, and other applications off Earth.
Our next chapter will examine the most commonly used Air Mass spectrum, AM1.5, and its various versions.
If you are already an expert in the Aerospace field and need a light source capable of Class AAA quality, our Sunbrick is a scalable solution for you. Starting at 20 cm x 20 cm, it can be scaled to any size you require without sacrificing Class AAA.
