Posted on January 24, 2023 (Updated on July 10, 2025)

Earth engine reproject: why does reprojecting a pixel at 30m scale gives me pixels with an area of ~550?

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What is scale in Google Earth Engine?

Understanding how Earth Engine handles scale is crucial to interpreting scientific results obtained from Earth Engine. Here, scale means pixel resolution. Unlike other GIS and image processing platforms, the scale of analysis is determined from the output, rather than the input.
 

How do I change the projection on Google Earth Engine?

You can use the . changeProj() image method to change the projection of an image in the Map display. Note, however, that the Google Map tiles, Map scale bar, geometry tools, and the Inspector coordinates are still tied to the Map object’s original canvas (EPSG:3857).
 

How do you find area on Google Earth Engine?

Tips:

  1. On your computer, open Google Earth.
  2. Search for a place, or select a location on the globe.
  3. On the left, click Measure. .
  4. Click the map to set measurement points.
  5. To remove a point, on the right, click Undo .
  6. To complete your line measurement, double-click on your last point, or click Done .


What projection is Google Earth using?

We accept imagery projected using a standard cartographic projection such as Universal Transverse Mercator (UTM), a satellite-based datum such as GRS80, or WGS84; or in Geographic Coordinates (aka “latitude/longitude”) with WGS84 datum. Images should be north-aligned and have rotation parameters set to zero.

What does a 1 to 50000 scale map mean?

1 : 50,000 means that. 1 unit of the map represents 50,000 units on the ground. or. 1 cm represents 50,000 cm.

How do I fix the scale on Google Earth?

Simply go to the View menu and click Scale Legend> The scale will change constantly as you zoom in and out.

Is Google Earth WGS84?

(Google uses the World Geodetic System WGS84 standard.) World coordinates, which reference a point on the map uniquely.

What datum does Google Earth use for elevation?

WGS84

The default horizontal datum setting on most GPS receivers is the World Geodetic System of 1984 (WGS84) and the elevations are based on the NAD83 ellipsoid.

What is the difference between UTM and WGS84?

The difference is that WGS 84 is a geographic coordinate system, and UTM is a projected coordinate system. Geographic coordinate systems are based on a spheroid and utilize angular units (degrees).
 

What does scale () function do?

scale() function in R Language is a generic function which centers and scales the columns of a numeric matrix. The center parameter takes either numeric alike vector or logical value. If the numeric vector is provided, then each column of the matrix has the corresponding value from center subtracted from it.
 

What is the earth scale?

But just how big is the Earth? The Earth has a radius of 2.439 kilometers / 1.516 miles and a diameter of only 12.742 km / 7.917 mi.

What is Google scale?

Scale Computing partnered with Google and Google Cloud Platform (GCP) to develop a hybrid cloud solution that makes it easy for organizations, including channel partners and MSPS, to move application workloads freely in the cloud or on-premises.