9

Can you suggest an approach to select January Landsat 5 data between 2000 to 2010 and calculate its mean?

In other words, the mean of the all January images from 2000 to 2010.

Aaron
  • 51,658
  • 28
  • 154
  • 317
P_P
  • 101
  • 1
  • 1
  • 4

1 Answers1

22

You nee to use ee.Filter.calendarRange(start,end,field) to filter by all Januaries from 2000 to 2010.

field could be:

  • field (String, default: "day_of_year"): The calendar field to filter over. Options are: 'year', 'month', 'hour', 'minute', 'day_of_year', 'day_of_month', and 'day_of_week'.

So, the code is:

var imageCollection = ee.ImageCollection("LANDSAT/LT05/C01/T1_TOA");

// Use ee.Filter.calendarRange to filter by year and month

var img = imageCollection.filter(ee.Filter.calendarRange(2000,2010,'year'))
.filter(ee.Filter.calendarRange(1,1,'month'));

// reduce image collection with mean()
var mean = img.mean();

// Set visualization parameters
var vizParams = {
  bands: ['B3', 'B2', 'B1'],
  min: 0,
  max: 0.5,
  gamma: [0.95, 1.1, 1]
};

// add layer
Map.addLayer(mean,vizParams);

This code process specifically your task description, doesn't consider cloud mask or a cloud coverage filter.

Community
  • 1
aldo_tapia
  • 13,560
  • 5
  • 30
  • 56
  • Thank You for your valuable answer. Thanks a lot, but i have a question here, var img = imageCollection.filter(ee.Filter.calendarRange(2000,2010,'year')) .filter(ee.Filter.calendarRange(1,1,'month'));

    It is taking only January 2000 and January 2010,

     – P_P Sep 23 '17 at 09:11
  • var img = imageCollection.filter(ee.Filter.calendarRange(2000,2010,'year')) .filter(ee.Filter.calendarRange(1,1,'month'));

    It is filtering all images from January 2000 to January2010. I need only january from every year.

    Thank you

     – P_P Sep 23 '17 at 09:34
  • @P_P weird, I test it and takes every year. Try with .filterDate(“2000-01-01” , “2010-01-31”) instead of first filter. – aldo_tapia Sep 23 '17 at 12:02
  • Thank You for your kind reply. I started with this .filterDate(“2000-01-01” , “2010-01-31”) but its is taking all images between these dates. – P_P Sep 24 '17 at 05:24
  • @P_P yes, but I said as remplace of first filter (year filter), you need to keep the second filter (month filter). – aldo_tapia Sep 24 '17 at 11:15