Exporting rain data to CSV file from Google Earth Engine

Question

I would like to get the CSV file of rain daily data from GSMAP for a specified polygon (mean in geometry).

I succeed in getting into it on a chart, but now I want to download the data and I'm having some trouble

Could you help me?

//Add Dates range, with las date available
var iniDate = ee.Date('2018-03-01')
var endDate = ee.Date(ee.List(GSMAP.get('date_range')).get(1)) //last date 

print('lastDay available', ee.Date(ee.List(GSMAP.get('date_range')).get(1)))

//Add ImageCollection
var filterGSMAP = GSMAP.filterDate(iniDate, endDate).select(['hourlyPrecipRateGC']);

//Initiate the date list with a day less than the availability, 
//as the last day available does not contain images:
var difdate = endDate.advance(-1, 'day').difference(iniDate, 'day'); //calculate steps/days in between
var createList = ee.List.sequence(0, difdate) //make list with the needed number of entries
var listdates = createList.map(function(day){ //change list into list of dates
return iniDate.advance(day, 'day')})
print(listdates)

//Summarize hourly precipitation data to daily precipitation data
//Then filter the image collection using the filterDate, which is (I think) easier than filtering 
//on year and doy consecutively:
var gsmapImageCollection  = ee.ImageCollection.fromImages(listdates.map(function(summarize_day){
var filterCol = filterGSMAP.filterDate(ee.Date(summarize_day), ee.Date(summarize_day).advance(1, 'day'))
return filterCol.sum().select(['hourlyPrecipRateGC'], ['dailyPrecipRateGC'])
.copyProperties(filterCol.first()).setMulti({
Date: ee.Date(summarize_day), 'system:time_start': ee.Date(summarize_day).millis()});}))
print(gsmapImageCollection)
print(ui.Chart.image.series(gsmapImageCollection, geometry, ee.Reducer.mean(), 5000)
.setChartType('ColumnChart'));

//Set a system:time_start property,
//so you can easily plot/filter etc the resulting image collection.
//Add the resulting image collection to the map
var VIS = {palette: ['1621a2','ffffff', '03ffff','13ff03','efff00','ffb103', 'ff2300'], min: 0, max: 50}
//Map.addLayer(gsmapImageCollection.first(), VIS, 'GSMap');

// Here is my doubt, how can i get the CSV file with two columns, day and acumulated rain.
//Export the time-series as a csv.
Export.table.toDrive({
  collection: gsmapImageCollection, 
  description: 'rain', 
  selectors: 'day, value', 
  fileFormat: 'CSV'
});

Answer 1

var Elv = ee.Geometry.Point(96.13322,16.90731);
Map.addLayer(Elv, {}, 'Yangon_INT')

// load in data and select dates 
var PRECIP = ee.ImageCollection("JAXA/GPM_L3/GSMaP/v6/operational")   
                 .filterDate('2021-01-01','2021-12-31');

//print(PRECIP);

var getPrecipit = function(image) {
  
  var time = ee.Date(ee.Image(image).get('system:time_start')).format().slice(0, 10); 
  
  var value_precipt = ee.Image(image)
    .reduceRegion(ee.Reducer.first(), Elv)
    .get('hourlyPrecipRate');
  
  return [time, value_precipt];
  
};

var count = PRECIP.size();

print("Number of values", count);

var precipit_list = PRECIP.toList(count).map(getPrecipit);

//print(precipit_list);

var myFeatures = ee.FeatureCollection(precipit_list.map(function(el){
  el = ee.List(el); // cast every element of the list
  var geom = Elv;
  return ee.Feature(geom, {
    'date': ee.String(el.get(0)),
    'value':ee.Number(el.get(1))
  });
}));

//print(myFeatures);

// Export features, specifying corresponding names.
Export.table.toDrive(myFeatures,
"2021", //my task
"GEE_Folder", //my export folder
"2021",  //file name
"CSV");