Total reflectance of built, cultivated and natural land surfaces. Data are to be used as "reference values only" as actual values will vary.
Format
A reflector_mspct object named materials.mspct
containing a collection of reflector_spct objects each with 491 rows
and 2 variables.
The variables for each spectrum are as follows:#'
w.length(nm)Rfr(fraction)
These member objects contain metadata stored as R attributes. Accessors to
the metadata are available: what_measured(), how_measured(),
when_measured(), and comment().
Note
This is a small selection from the ASTER database. See: https://speclib.jpl.nasa.gov/. Reproduced from the ECOSTRESS Spectral Library through the courtesy of the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California. Copyright (c) 2017, California Institute of Technology. ALL RIGHTS RESERVED.
References
Meerdink, S. K., Hook, S. J., Roberts, D. A., & Abbott, E. A. (2019). The ECOSTRESS spectral library version 1.0. Remote Sensing of Environment, 230(111196), 1–8. ASTER spectral library.
Baldridge, A. M., S.J. Hook, C.I. Grove and G. Rivera, 2009.. The ASTER Spectral Library Version 2.0. Remote Sensing of Environment, vol 113, pp. 711-715.
Examples
materials.mspct$dry.grass
#> Object: reflector_spct [1,085 x 2]
#> Wavelength range 380.49-14011 nm, step 1.2-38 nm
#> Label: Dry grass
#> Variables:
#> w.length: Wavelength [nm]
#> Rfr: Total spectral reflectance [/1]
#> --
#> # A tibble: 1,085 × 2
#> w.length Rfr
#> <dbl> <dbl>
#> 1 380. 0.142
#> 2 385. 0.145
#> 3 400. 0.157
#> 4 410. 0.168
#> 5 420. 0.176
#> 6 437. 0.193
#> 7 440. 0.197
#> 8 442. 0.199
#> 9 444. 0.202
#> 10 459. 0.213
#> # ℹ 1,075 more rows
summary(materials.mspct$dry.grass)
#> Summary of reflector_spct [1,085 x 2] object: anonymous
#> Wavelength range 380.49-14011 nm, step 1.2-38 nm
#> Label: Dry grass
#> Variables:
#> w.length: Wavelength [nm]
#> Rfr: Total spectral reflectance [/1]
#> --
#> w.length Rfr
#> Min. : 380.5 Min. :0.02399
#> 1st Qu.: 2424.5 1st Qu.:0.05275
#> Median : 4423.3 Median :0.14038
#> Mean : 5328.9 Mean :0.22144
#> 3rd Qu.: 8087.6 3rd Qu.:0.37159
#> Max. :14011.0 Max. :0.67606
what_measured(materials.mspct$dry.grass)
#> [1] "Dry grass"
how_measured(materials.mspct$dry.grass)
#> [1] NA
cat(comment(materials.mspct$dry.grass))
#> Name: Dry grass
#> Type: Vegetation
#> Class: Grasses
#> Subclass: Dry grass
#> Particle Size: Solid
#> Sample No.: drygrass.doc
#> Owner: JHU
#> Wavelength Range: All
#> Origin: The entire spectral range was measured at Johns Hopkins University.
#>
#> Description: Dry grass. Spectra were assembled from two segments; the
#> bidirectional VNIR and SWIR comprising segment one, and the hemispherical
#> MWIR and TIR comprising segment two. The VNIR/SWIR spectrum was
#> measured in the laboratory at JHU with a GER IRIS Mark IV, using a large piece
#> of sod. The grass was illuminated from directly above and measured at a
#> reflectance angle of 60 degrees to avoid viewing the thatch.
#> Measurement: Bidirectional and directional hemispherical reflectance.
#> First Column: X
#> Second Column: Y
#> X Units: Wavelength (micrometers)
#> Y Units: Reflectance (percent)
#> First X Value: 0.38049
#> Last X Value: 14.011
#> Number of X Values: 2559
#> Additional Information: None.
#>
names(materials.mspct)
#> [1] "construction.asphalt" "construction.concrete."
#> [3] "aluminum.metal" "galvanized.steel.metal"
#> [5] "light.yellowish.brown.clay" "black.loam"
#> [7] "dry.grass" "grass"
#> [9] "conifer" "decidous"
#> [11] "fine.snow" "coarse.granular.snow"
#> [13] "medium.granular.snow" "gold.plate"
summary(materials.mspct)
#> Summary of reflector_mspct [14 x 1] object: materials.mspct
#> # A tibble: 14 × 8
#> spct.idx class dim w.length.min w.length.max colnames multiple.wl Rfr.type
#> <chr> <chr> <chr> <dbl> <dbl> <list> <dbl> <chr>
#> 1 construc… refl… [400… 420 14000 <chr> 1 total
#> 2 construc… refl… [365… 420 14000 <chr> 1 total
#> 3 aluminum… refl… [350… 300 12500 <chr> 1 total
#> 4 galvaniz… refl… [368… 300 12500 <chr> 1 total
#> 5 light.ye… refl… [1,4… 400 14983. <chr> 1 total
#> 6 black.lo… refl… [1,6… 400 14011. <chr> 1 total
#> 7 dry.grass refl… [1,0… 380. 14011 <chr> 1 total
#> 8 grass refl… [380… 302 14000 <chr> 1 total
#> 9 conifer refl… [387… 302 14000 <chr> 1 total
#> 10 decidous refl… [391… 302 14000 <chr> 1 total
#> 11 fine.snow refl… [969… 300 14010 <chr> 1 total
#> 12 coarse.g… refl… [969… 300 14010 <chr> 1 total
#> 13 medium.g… refl… [969… 300 14010 <chr> 1 total
#> 14 gold.pla… refl… [1,2… 2000. 15385. <chr> 1 total