What one sensor can settle
Objective
For a single sensor, state how strongly its measurements support different ground values at a chosen wavelength, including the ambiguity that remains because different surfaces can produce the same reading.
Scoped How stages are defined
Most satellite sensors measure a few broad bands. Quite different surface reflectance spectra can produce identical readings through the same spectral response, an effect known as metamerism. The ambiguity is real, and a method that hides it overstates what the data show.
Knowing how wide that ambiguity is tells a user what one sensor can and cannot settle on its own, and when a second source is worth acquiring.
We pass surfaces whose spectra have been measured independently and in detail through the real sensor's spectral response, and compare the ambiguity RefCal reports with what the detailed measurements show. We keep track of which narrowing comes from the observations and which from stated assumptions.
The reported range of ground values contains what the detailed spectra show, and narrows no further than the observations and stated assumptions support.
Established work this area builds on. Results from the programme are published separately, with their data and limits.
- Spherical sampling methods for the calculation of metamer mismatch volumes (2019) M. Mackiewicz, H. J. Rivertz and G. D. Finlayson How the range of spectra consistent with one sensor's reading can be bounded.
Questions about this work?
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