{
    "cells": [
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "<a href=\"https://githubtocolab.com/gee-community/geemap/blob/master/examples/notebooks/36_quality_mosaic.ipynb\" target=\"_parent\"><img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open in Colab\"/></a>\n",
                "\n",
                "Uncomment the following line to install [geemap](https://geemap.org) if needed."
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "# !pip install geemap"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "# How to find out the greenest day of the year"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "## Import libraries"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "import ee\n",
                "import geemap"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "## Create an interactive map"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "Map = geemap.Map()\n",
                "Map"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "## Define a region of interest (ROI)"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "countries = ee.FeatureCollection('users/giswqs/public/countries')\n",
                "Map.addLayer(countries, {}, 'coutries')"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "roi = countries.filter(ee.Filter.eq('id', 'USA'))\n",
                "Map.addLayer(roi, {}, 'roi')"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "## Filter ImageCollection"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "start_date = '2019-01-01'\n",
                "end_date = '2019-12-31'\n",
                "\n",
                "l8 = (\n",
                "    ee.ImageCollection('LANDSAT/LC08/C01/T1_TOA')\n",
                "    .filterBounds(roi)\n",
                "    .filterDate(start_date, end_date)\n",
                ")"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "# print(l8.size().getInfo())"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "## Create a median composite"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "median = l8.median()\n",
                "\n",
                "visParams = {\n",
                "    'bands': ['B4', 'B3', 'B2'],\n",
                "    'min': 0,\n",
                "    'max': 0.4,\n",
                "}\n",
                "\n",
                "Map.addLayer(median, visParams, 'Median')"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "## Define functions to add time bands"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "def addNDVI(image):\n",
                "    ndvi = image.normalizedDifference(['B5', 'B4']).rename('NDVI')\n",
                "    return image.addBands(ndvi)"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "def addDate(image):\n",
                "    img_date = ee.Date(image.date())\n",
                "    img_date = ee.Number.parse(img_date.format('YYYYMMdd'))\n",
                "    return image.addBands(ee.Image(img_date).rename('date').toInt())"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "def addMonth(image):\n",
                "    img_date = ee.Date(image.date())\n",
                "    img_doy = ee.Number.parse(img_date.format('M'))\n",
                "    return image.addBands(ee.Image(img_doy).rename('month').toInt())"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "def addDOY(image):\n",
                "    img_date = ee.Date(image.date())\n",
                "    img_doy = ee.Number.parse(img_date.format('D'))\n",
                "    return image.addBands(ee.Image(img_doy).rename('doy').toInt())"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "## Map over an ImageCollection"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "withNDVI = l8.map(addNDVI).map(addDate).map(addMonth).map(addDOY)"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "## Create a quality mosaic"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "greenest = withNDVI.qualityMosaic('NDVI')"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "greenest.bandNames().getInfo()"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "## Display the max value band"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "ndvi = greenest.select('NDVI')\n",
                "palette = [\n",
                "    '#d73027',\n",
                "    '#f46d43',\n",
                "    '#fdae61',\n",
                "    '#fee08b',\n",
                "    '#d9ef8b',\n",
                "    '#a6d96a',\n",
                "    '#66bd63',\n",
                "    '#1a9850',\n",
                "]\n",
                "Map.addLayer(ndvi, {'palette': palette}, 'NDVI')"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "Map.addLayer(greenest, visParams, 'Greenest pixel')\n",
                "Map"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "## Display time bands"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "Map.addLayer(\n",
                "    greenest.select('month'),\n",
                "    {'palette': ['red', 'blue'], 'min': 1, 'max': 12},\n",
                "    'Greenest month',\n",
                ")"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "Map.addLayer(\n",
                "    greenest.select('doy'),\n",
                "    {'palette': ['brown', 'green'], 'min': 1, 'max': 365},\n",
                "    'Greenest doy',\n",
                ")"
            ]
        }
    ],
    "metadata": {
        "kernelspec": {
            "display_name": "Python 3",
            "language": "python",
            "name": "python3"
        }
    },
    "nbformat": 4,
    "nbformat_minor": 5
}