Leafy Spurge from a Distance

Our first round of work capturing the spectral signatures of leafy spurge is complete. During peak flowering period, leafy spurge is visible from far away, allowing dense patches to be identified relatively easily.

When in full flower, the yellowy-green color of leafy spurge stands out like a sore thumb.

When in full flower, the yellowy-green color of leafy spurge stands out like a sore thumb.

Light signatures are often expressed in reflectance units, which vary from 0 to 1 (100% of light hitting the subject(s) is being reflected back). To place the reflectance on the proper scale, one needs to capture idealized “pure” reference signatures against which the signatures from the land cover can be compared. Here Lindsi and Henry use a white reference block as the 100% reflective surface before recording the signatures of the leafy spurge all around them.

Taking a white reference reading

Taking a white reference reading