WorksheetsGoogle Earth Engine Quiz
Total questions: 16
Worksheet time: 16mins
How can you filter and display the India boundary in Google Earth Engine from a global boundary dataset?
Using regions.filter(ee.Filter.eq('country_na', 'India'))
Using regions.select('India')
Using regions.clip('India')
Using regions.map('India')
what does this code snippet do?
Export.table.toDrive({
collection: lakecoll,
description: 'Varthur lake',
folder: 'Lakes',
fileFormat: 'SHP'
});
Export a raster image of the lake to Google Drive as a shapefile (SHP).
Export a feature collection representing the lake to Google Drive as a shapefile (SHP).
Export a satellite image of the lake to Google Earth as a KML file.
Export a topographic map of the lake to Google Drive as a CSV file.
What does the following code do in Google Earth Engine?
var bufferValue = 5000;
var buff = aoi.buffer(bufferValue, 1);
Map.addLayer(buff);
Creates a 5000km buffer around aoi and adds it to the map
Creates a 5000-meter buffer around aoi and adds it to the map
Clips the area of interest to a 5000-meter radius
Creates a boundary within 5000 meters of the AOI and removes it from the map
What does the .union() function do when applied to bufferedPoints in this code?
Merges multiple point buffers into one dissolved layer
Creates a buffer around each point
Filters the points to include only those within the buffer
Removes overlapping areas between buffered points
What is the purpose of the map() function in Google Earth Engine when applied to a FeatureCollection?
It filters the FeatureCollection based on specific criteria.
It applies a function to each feature in the FeatureCollection and returns a new FeatureCollection.
It merges two FeatureCollections into one.
It removes features from the FeatureCollection based on a condition.
Which of the following statements about const is true?
Variables declared with const can be reassigned.
const is block-scoped.
Variables declared with const are not block-scoped.
Variables declared with const can be hoisted like var.
What will be the output of the following code?
const y = 10;
y = 15;
console.log(y);
15
10
undefined
TypeError
Which of the following correctly describes the behavior of variables declared with let?
They are function-scoped.
They are globally scoped.
They are block-scoped and can be reassigned.
They cannot be reassigned after being initialized.
what is the purpose of the given function?
var ImageColl = L8.map(function(image)
{ var ndvi = image.normalizedDifference(['B5','B4']).rename('NDVI');
return image.addBands(ndvi); })
To filter images with a cloud cover greater than 5%
To calculate and add the NDVI band to each image in the ImageCollection
To visualize the NDVI time series chart
To set the title and axis options for the chart
What is the purpose of the reduceRegion function?
To display the DEM layer on the map
To calculate a summary statistic for pixel values within the region
To clip the DEM to the region of interest (aoi)
To calculate the slope from the DEM
What would happen if the maxPixels parameter is omitted in the reduceRegion function?
It would throw an error if the number of pixels exceeds a default limit
The function will reduce the image without any pixel limit
The function will return the maximum pixel value instead of the mean
The function will only process the first 100 pixels
What does the ee.Reducer.mean() function compute when used with reduceRegion() in Google Earth Engine?
The minimum value of the pixels in the specified region
The average value of the pixels in the specified region
The maximum value of the pixels in the specified region
The total sum of the pixels in the specified region
In the context of the reduceRegion() function, which reducer would you use to count the number of valid (non-masked) pixels in a region?
ee.Reducer.mean()
ee.Reducer.count()
ee.Reducer.sum()
ee.Reducer.median()
What does the ee.ImageCollection.min() function do when applied to an image collection?
Returns the image with the minimum mean pixel value across the collection
Creates an image where each pixel is the minimum value of that pixel across the entire collection
Counts the number of images in the collection
Returns the first image in the collection
What does the ee.ImageCollection.first() function return?
The first non-null pixel value for each pixel in the collection
The first image in the image collection (usually by acquisition date)
The first band from each image in the collection
The image with the highest mean pixel value
In the following Earth Engine code snippet, what is the role of the xProperty: 'system:time_start' parameter in the ui.Chart.image.series function?
It specifies the y-axis variable for the NDVI values in the chart.
It defines the property used for labeling the x-axis, indicating the time of each image in the series.
It selects the region over which to calculate the mean NDVI value.
It sets the time zone for the dates displayed on the chart.
