RrsTrans

The R package RrsTrans is created as an appendix of our recent study entitled “A transfer model to determine the above-water remote-sensing reflectance from the underwater remote-sensing ratio” by Bi et al. (202x). RrsTrans includes six models: one from the paper above, Lee et al. (2002), Mobely (1999), Loisel (2008), Lee et al. (2011), and Morel and Gentili (1996).

Installation

You can install the development version of RrsTrans like so:

remotes::install_github("bishun945/RrsTrans")

Online tool

A shiny-based online tool has been added to this package. Please refer it via the link:

https://bishun945.shinyapps.io/RrsTransShinny/

Example

This is a basic example which shows you how to run the models in our package:

library(RrsTrans)
library(data.table)
data("demo_spec")

# parameters preparation
wavelen  = demo_spec[Theta == 40, wavelen]
rrs      = demo_spec[Theta == 40, rrs_nadir]
Rrs      = demo_spec[Theta == 40, Rrs]
at       = demo_spec[Theta == 40, at]
bbt      = demo_spec[Theta == 40, bbt]
bbw      = demo_spec[Theta == 40, bbw]
suntheta = 59.90437
Theta    = 40
Phi      = 135
windspd  = 6
cloud    = 0
Temp     = 1.1
Sal      = 31.1

# run models
nw = WOPP(Temp, Sal, wavelen)$nw
Rrs_Lee02 = trans_Lee02(rrs)
Rrs_Loisel08 = trans_Loisel08(rrs, suntheta)
Rrs_Lee11 = trans_Lee11(at, bbt, bbw, Theta, Phi, suntheta)
Rrs_Bi22 = trans_Bi22(rrs, Theta, Phi, suntheta, windspd, cloud, nw = nw)
Rrs_Mobley99 = trans_Mobley99(rrs)
Rrs_Morel96 = trans_Morel96(rrs, wavelen, Theta, suntheta)

# plot
pal_col = rainbow(n=6)
plot(wavelen, Rrs, col = "black", type = "l",
     xlim = c(400, 810), ylim = c(0, 0.012),
     xlab = "Wavelength [nm]", ylab = "Rrs [1/sr]")
lines(wavelen, Rrs_Bi22, col = pal_col[1], type = "l")
lines(wavelen, Rrs_Lee02, col = pal_col[2], type = "l")
lines(wavelen, Rrs_Loisel08, col = pal_col[3], type = "l")
lines(wavelen, Rrs_Lee11, col = pal_col[4], type = "l")
lines(wavelen, Rrs_Morel96, col = pal_col[5], type = "l")
lines(wavelen, Rrs_Mobley99, col = pal_col[6], type = "l")
lines(wavelen, Rrs, col = "black", type = "l", lty = 2)
legend(x = 810, y = 0.012, xjust = 1, yjust = 1,
       c("HydroLight", "Bi22", "Lee02", "Loisel08",
         "Lee11", "Morel96", "Mobley99"),
       col = c("black", pal_col), lty = c(1, 2, rep(1, 5)),
       x.intersp = 0.5, y.intersp = 0.8)

References

• Lee, ZhongPing, Kendall L. Carder, and Robert A. Arnone. “Deriving Inherent Optical Properties from Water Color: A Multiband Quasi-Analytical Algorithm for Optically Deep Waters.” Applied Optics 41, no. 27 (September 20, 2002): 5755. https://doi.org/10.1364/AO.41.005755.

• Lee, Zhongping, Keping Du, Kenneth J. Voss, Giuseppe Zibordi, Bertrand Lubac, Robert Arnone, and Alan Weidemann. “An Inherent-Optical-Property-Centered Approach to Correct the Angular Effects in Water-Leaving Radiance.” Applied Optics 50, no. 19 (July 1, 2011): 3155. https://doi.org/10.1364/AO.50.003155.

• Loisel, Hubert. “Rrs(0+) -> Rrs(0-) & Water Coefficients.” Ocean Color Forum, Inherent OPtical Properties Workshop, 2008. http://oceancolor.gsfc.nasa.gov/forum/oceancolor/topic_show.pl?tid=2657.

• Mobley, Curtis D. “Estimation of the Remote-Sensing Reflectance from above-Surface Measurements.” Applied Optics 38, no. 36 (December 20, 1999): 7442. https://doi.org/10.1364/AO.38.007442.

• Morel, André, and Bernard Gentili. “Diffuse Reflectance of Oceanic Waters III Implication of Bidirectionality for the Remote-Sensing Problem.” Applied Optics 35, no. 24 (August 20, 1996): 4850. https://doi.org/10.1364/AO.35.004850.

• Röttgers, R, R Doerffer, D McKee, and W Schönfeld. “The Water Optical Properties Processor (WOPP): Pure Water Spectral Absorption, Scattering and Real Part of Refractive Index Model.” Technical Report No WOPP-ATBD/WRD6, 2016. https://calvalportal.ceos.org/tools.