The problem is that when I calculate the maximum value, the resolution deprecate, while I need to maintain the original resolution (10 m).
Does anyone know how to calculate the pixel-wise max value while maintaing the original resolution (10m)?
The code:
# Create a monthly composite
years <- 2018:2023
months <- 1:12
for (y in years){
for (m in months) {
t <- as.Date(paste0(y,'-',m,'-01'), format="%Y-%m-%d")
tt <- ceiling_date(ymd(t), 'month') - days(1)
if(nchar(month(t))==1){mm <- paste0("0",month(t))} else {mm <- as.character(month(t))}
if(nchar(day(t))==1){dd <- paste0("0",day(t))} else {dd <- as.character(day(t))}
iniz <- paste0(year(t),"-",mm,"-",dd)
fine <- paste0(year(t),"-",mm,"-",day(tt))
ndvi_composite <- dataset$
filterDate(iniz,fine)$ #'2019-01-01', '2019-12-31'
filter(ee$Filter$calendarRange(1, field = "month"))$
map(S2_clean)$
max() ### here if I compute the maximum the resolution is degradated
# Download raster
ee_raster <- ee_as_raster(
image = ndvi_max,
region = aoi_gee$geometry(),
dsn = paste0("E:/GEE/NDVI_MAX_",mm,"_",y,".tif"),
#scale = 2000,
via = "drive")
# Clean a Google Drive folder
ee_clean_container(name = "rgee_backup", type = "drive")
}
}
without max():
> ee_print(ndvi_composite)
──────────────────────────────────────────────────────────────────────── Earth Engine ImageCollection ──
ImageCollection Metadata:
- Class : ee$ImageCollection
- Number of Images : 114
- Number of Properties : 23
- Number of Pixels* : 13746389154
- Approximate size* : 40.97 GB
Image Metadata (img_index = 0):
- ID : no_id
- system:time_start : 2019-01-02 10:28:48
- Number of Bands : 1
- Bands names : nd
- Number of Properties : 3
- Number of Pixels* : 120582361
- Approximate size* : 367.99 MB
Band Metadata (img_band = 'nd'):
- EPSG (SRID) : WGS 84 / UTM zone 32N (EPSG:32632)
- proj4string : +proj=utm +zone=32 +datum=WGS84 +units=m +no_defs
- Geotransform : 10 0 300000 0 -10 4900020
- Nominal scale (meters) : 10
- Dimensions : 10981 10981
- Number of Pixels : 120582361
- Data type : FLOAT
- Approximate size : 367.99 MB
────────────────────────────────────────────────────────────────────────────────────────────────────────
NOTE: (*) Properties calculated considering a constant geotransform and data type.
With max(), the crs and the resolution change:
ee_print(ndvi_composite)
────────────────────────────────────────────────────────────────────────────────── Earth Engine Image ──
Image Metadata:
- Class : ee$Image
- ID : no_id
- Number of Bands : 1
- Bands names : nd
- Number of Properties : 0
- Number of Pixels* : 64800
- Approximate size* : 202.50 KB
Band Metadata (img_band = nd):
- EPSG (SRID) : WGS 84 (EPSG:4326)
- proj4string : +proj=longlat +datum=WGS84 +no_defs
- Geotransform : 1 0 0 0 1 0
- Nominal scale (meters) : 111319.5
- Dimensions : 360 180
- Number of Pixels : 64800
- Data type : FLOAT
- Approximate size : 202.50 KB
────────────────────────────────────────────────────────────────────────────────────────────────────────
NOTE: (*) Properties calculated considering a constant geotransform and data type.