Asteroids are commonly classified according to two criteria: the characteristics of their orbits, and features of their reflectance spectrum.
The purple colour is the easiest of the four to distinguish against the reflectance spectrum of the mudflats on which the crabs live.
Hyperspectral imaging from aircraft or satellites can provide remotely sensed reflectance spectra to help detect such graves.
The atmosphere of Titan is opaque at many wavelengths and a complete reflectance spectrum of the surface is impossible to acquire from the outside.
The object has a red-sloped reflectance spectrum, saying that the surface could be rich in organic material such as tholins.
With so much debris of all shapes and sizes, the only hope of identification was through the data cube's reflectance spectrum.
The reflectance spectra of these samples may be found in , and their approximate Munsell notations are listed aside.
In visible light this object is neutral or slightly red in color and has a flat featureless reflectance spectrum.
A gray card is a flat object of a neutral gray color that derives from a flat reflectance spectrum.
Ida was classified as an S-type asteroid based on the similarity of its reflectance spectra with similar asteroids.