A18c Checkpoint

Import libraries¶

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import ee
import geemap

import ee import geemap

Create an interactive map¶

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Map = geemap.Map(center=[40, -100], zoom=4)

Map = geemap.Map(center=[40, -100], zoom=4)

Add Earth Engine Python script¶

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# Add Earth Engine dataset
image = ee.Image("USGS/SRTMGL1_003")

#  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#  Chapter:      A1.8 Monitoring Gold Mining Activity using SAR
#  Checkpoint:   A18c
#  Authors:      Lucio Villa, Sidney Novoa, Milagros Becerra,
#                Andréa Puzzi Nicolau, Karen Dyson, Karis Tenneson, John Dilger
#  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

###########################
# / Section Two
###########################

# Define the area of study.
aoi = ee.FeatureCollection("projects/gee-book/assets/A1-8/mdd")

# Center the map at the aoi.
Map.centerObject(aoi, 9)

# Create an empty image.
empty = ee.Image().byte()

# Convert the area of study to an EE image object
# so we can visualize only the boundary.
aoiOutline = empty.paint({"featureCollection": aoi, "color": 1, "width": 2})

# Select the satellite basemap view.
Map.setOptions("SATELLITE")

# Add the area of study boundary to the map.
Map.addLayer(aoiOutline, {"palette": "red"}, "Area of Study")


# Function to mask the SAR images acquired with an incidence angle
# lower equal than 31 and greater equal than 45 degrees.
def maskAngle(image):
    angleMask = image.select("angle")
    return image.updateMask(angleMask.gte(31).And(angleMask.lte(45)))


# Function to get the SAR Collection.
def getCollection(dates, roi, orbitPass0):
    sarCollFloat = (
        ee.ImageCollection("COPERNICUS/S1_GRD_FLOAT")
        .filterBounds(roi)
        .filterDate(dates[0], dates[1])
        .filter(ee.Filter.eq("orbitProperties_pass", orbitPass0))
    )
    return sarCollFloat.map(maskAngle).select(["VV", "VH"])


# Define variables: the period of time and the orbitpass.
listOfDates = ["2021-01-01", "2022-01-01"]
orbitPass = "DESCENDING"

# Apply the function to get the SAR Collection.
sarImageColl = getCollection(listOfDates, aoi, orbitPass)
print("SAR Image Collection", sarImageColl)

# -----------------------------------------------------------------------
# CHECKPOINT
# -----------------------------------------------------------------------


# Function to get dates in 'YYYY-MM-dd' format.
def getDates(dd):
    return ee.Date(dd).format("YYYY-MM-dd")


# Function to get a SAR Mosaic clipped to the study area.
def mosaicSAR(dates1):
    dates1 = ee.Date(dates1)
    imageFilt = sarImageColl.filterDate(dates1, dates1.advance(1, "day"))
    return (
        imageFilt.mosaic()
        .clip(aoi)
        .set(
            {
                "system:time_start": dates1.millis(),
                "dateYMD": dates1.format("YYYY-MM-dd"),
            }
        )
    )


# Function to get a SAR Collection of mosaics by date.
datesMosaic = (
    ee.List(sarImageColl.aggregate_array("system:time_start")).map(getDates).distinct()
)

# Get a SAR List and Image Collection of mosaics by date.
getMosaicList = datesMosaic.map(mosaicSAR)
getMosaicColl = ee.ImageCollection(getMosaicList)
print("get Mosaic Collection", getMosaicColl)

# Visualize results.
sarVis = {"bands": ["VV", "VH", "VV"], "min": [-18, -23, 3], "max": [-4, -11, 15]}

image1 = (
    getMosaicColl.filter(ee.Filter.eq("dateYMD", "2021-01-04"))
    .first()
    .log10()
    .multiply(10.0)
)
image2 = (
    getMosaicColl.filter(ee.Filter.eq("dateYMD", "2021-12-18"))
    .first()
    .log10()
    .multiply(10.0)
)

Map.addLayer(image1, sarVis, "Sentinel-1 | 2021-01-04")
Map.addLayer(image2, sarVis, "Sentinel-1 | 2021-12-18")

# -----------------------------------------------------------------------
# CHECKPOINT
# -----------------------------------------------------------------------

# Add Earth Engine dataset image = ee.Image("USGS/SRTMGL1_003") # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ # Chapter: A1.8 Monitoring Gold Mining Activity using SAR # Checkpoint: A18c # Authors: Lucio Villa, Sidney Novoa, Milagros Becerra, # Andréa Puzzi Nicolau, Karen Dyson, Karis Tenneson, John Dilger # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ########################### # / Section Two ########################### # Define the area of study. aoi = ee.FeatureCollection("projects/gee-book/assets/A1-8/mdd") # Center the map at the aoi. Map.centerObject(aoi, 9) # Create an empty image. empty = ee.Image().byte() # Convert the area of study to an EE image object # so we can visualize only the boundary. aoiOutline = empty.paint({"featureCollection": aoi, "color": 1, "width": 2}) # Select the satellite basemap view. Map.setOptions("SATELLITE") # Add the area of study boundary to the map. Map.addLayer(aoiOutline, {"palette": "red"}, "Area of Study") # Function to mask the SAR images acquired with an incidence angle # lower equal than 31 and greater equal than 45 degrees. def maskAngle(image): angleMask = image.select("angle") return image.updateMask(angleMask.gte(31).And(angleMask.lte(45))) # Function to get the SAR Collection. def getCollection(dates, roi, orbitPass0): sarCollFloat = ( ee.ImageCollection("COPERNICUS/S1_GRD_FLOAT") .filterBounds(roi) .filterDate(dates[0], dates[1]) .filter(ee.Filter.eq("orbitProperties_pass", orbitPass0)) ) return sarCollFloat.map(maskAngle).select(["VV", "VH"]) # Define variables: the period of time and the orbitpass. listOfDates = ["2021-01-01", "2022-01-01"] orbitPass = "DESCENDING" # Apply the function to get the SAR Collection. sarImageColl = getCollection(listOfDates, aoi, orbitPass) print("SAR Image Collection", sarImageColl) # ----------------------------------------------------------------------- # CHECKPOINT # ----------------------------------------------------------------------- # Function to get dates in 'YYYY-MM-dd' format. def getDates(dd): return ee.Date(dd).format("YYYY-MM-dd") # Function to get a SAR Mosaic clipped to the study area. def mosaicSAR(dates1): dates1 = ee.Date(dates1) imageFilt = sarImageColl.filterDate(dates1, dates1.advance(1, "day")) return ( imageFilt.mosaic() .clip(aoi) .set( { "system:time_start": dates1.millis(), "dateYMD": dates1.format("YYYY-MM-dd"), } ) ) # Function to get a SAR Collection of mosaics by date. datesMosaic = ( ee.List(sarImageColl.aggregate_array("system:time_start")).map(getDates).distinct() ) # Get a SAR List and Image Collection of mosaics by date. getMosaicList = datesMosaic.map(mosaicSAR) getMosaicColl = ee.ImageCollection(getMosaicList) print("get Mosaic Collection", getMosaicColl) # Visualize results. sarVis = {"bands": ["VV", "VH", "VV"], "min": [-18, -23, 3], "max": [-4, -11, 15]} image1 = ( getMosaicColl.filter(ee.Filter.eq("dateYMD", "2021-01-04")) .first() .log10() .multiply(10.0) ) image2 = ( getMosaicColl.filter(ee.Filter.eq("dateYMD", "2021-12-18")) .first() .log10() .multiply(10.0) ) Map.addLayer(image1, sarVis, "Sentinel-1 | 2021-01-04") Map.addLayer(image2, sarVis, "Sentinel-1 | 2021-12-18") # ----------------------------------------------------------------------- # CHECKPOINT # -----------------------------------------------------------------------

Display the interactive map¶

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Map

Map