Spatially Explicit Estimation of Clay and Organic Carbon Content in Agricultural Soils Using Multi-Annual Imaging Spectroscopy Data

Table 8

Mean deviation (RMSE) of predicted clay and organic carbon contents in the overlap area of the HyMap flight strips and standard errors of PLSR models generated using the spectra transformed to absorbance (Abs) and spectra transformed to first derivative of absorbance (Abs_Deriv1). Bold numbers indicate model parameters presented in Table 7.

Day of acquisition	Number of pixels estimated	Clay				Organic carbon
		RMSEoverlap		SEP* or SEC**		RMSEoverlap		SEP* or SEC**
		Abs	Abs_Deriv1	Abs	Abs_Deriv1	Abs	Abs_Deriv1	Abs	Abs_Deriv1
August 9, 2004	36015	69.63	38.99	𝟐𝟑.𝟑𝟗^∗∗	28.35**	3.86	2.20	2.35**	𝟐.𝟏𝟑^∗∗
May 27, 2005	260206	22.46	17.03	20.96*	𝟏𝟗.𝟒𝟏^∗	2.34	0.60	3.13*	𝟐.𝟎𝟕^∗
July 29, 2008	60308	12.95	15.39	𝟏𝟓.𝟗𝟗^∗∗	22.89**	2.21	0.79	1.88**	𝟏.𝟔𝟏^∗∗

SEC: standard error of calibration in (g kg⁻¹) and SEP: standard error of validation in (g kg⁻¹).