getBits: Extract bitcoded QA information from bin value
qc_summary: Initial weigths based on Quality reliability of VI pixel,
suit for MOD13A1, MOD13A2 and MOD13Q1 (SummaryQA band).
qc_5l: Initial weights based on Quality control of five-level
confidence score, suit for MCD15A3H(LAI, FparLai_QC), MOD17A2H(GPP, Psn_QC)
and MOD16A2(ET, ET_QC).
qc_StateQA: Initial weights based on StateQA, suit for MOD09A1, MYD09A1.
qc_FparLai
qc_NDVI3g: For NDVI3g
qc_NDVIv4: For NDVIv4
getBits(x, start, end = start) qc_summary(QA, wmin = 0.2, wmid = 0.5, wmax = 1) qc_StateQA(QA, wmin = 0.2, wmid = 0.5, wmax = 1) qc_5l(QA, wmin = 0.2, wmid = 0.5, wmax = 1) qc_FparLai(QA, FparLai_QC = NULL, wmin = 0.2, wmid = 0.5, wmax = 1) qc_NDVI3g(QA, wmin = 0.2, wmid = 0.5, wmax = 1) qc_NDVIv4(QA, wmin = 0.2, wmid = 0.5, wmax = 1) qc_SPOT(QA, wmin = 0.2, wmid = 0.5, wmax = 1)
| x | Binary value |
|---|---|
| start | Bit starting position, count from zero |
| end | Bit ending position |
| QA | quality control variable |
| wmin | Double, minimum weigth (i.e. weight of snow, ice and cloud). |
| wmid | Dougle, middle weight, i.e. marginal |
| wmax | Double, maximum weight, i.e. good |
| FparLai_QC | Another QC flag of |
A list object with
weigths: Double vector, initial weights.
QC_flag: Factor vector, with the level of
c("snow", "cloud", "shadow", "aerosol", "marginal", "good")
If FparLai_QC specified, I_margin = SCF_QC >= 2 & SCF_QC <= 3.
https://developers.google.com/earth-engine/datasets/catalog/MODIS_006_MOD13A1
https://developers.google.com/earth-engine/datasets/catalog/MODIS_006_MCD15A3H
Erwin Wolters, Else Swinnen, Carolien Toté, Sindy Sterckx. SPOT-VGT COLLECTION 3 PRODUCTS USER MANUAL V1.2, 2018, P47
set.seed(100) QA <- as.integer(runif(100, 0, 2^7)) r1 <- qc_summary(QA, wmin = 0.2, wmid = 0.5, wmax = 1) r2 <- qc_StateQA(QA, wmin = 0.2, wmid = 0.5, wmax = 1) r_5l <- qc_5l(QA, wmin = 0.2, wmid = 0.5, wmax = 1) r_NDVI3g <- qc_NDVI3g(QA, wmin = 0.2, wmid = 0.5, wmax = 1) r_NDVIv4 <- qc_NDVIv4(QA, wmin = 0.2, wmid = 0.5, wmax = 1)