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The MODIS vegetation indices collection shows a resolution of 111319.4 metres in Google Earth Engine when, in fact, it should be 1000 metres.

Below is my code:

var Veg = ee.ImageCollection("MODIS/006/MOD13A2").filterDate ('2009-04-15', 
'2009-04-30').max().select('NDVI');
print('Scale in meters:', Veg.projection().nominalScale());

I checked the resolution because I wanted to change resolution of my 90m Digital Elevation Model to 1000m using MYD13A2 data, but it gave the following error:

Layer 1: Tile error: Too many input pixels per output pixel. Need 1440001, but only 10000 allowed.
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The nominal scale of the a MOD13A2 image is indeed around 1000m:

var sampleImage = ee.Image(ee.ImageCollection("MODIS/006/MOD13A2").first())
                    .select('NDVI');

print('Scale in meters:', sampleImage.projection().nominalScale());

However, your code example is not printing out the scale of an MOD13A2 image, but rather is printing out the scale of a composited image (which happens to be derived from MOD13A2 images). Your script calls ee.ImageCollection.max(), which reduces all images in an ee.ImageCollection to a single ee.Image object. Because the images in the collection may (and often do) have different projections, a default projection of WGS84 with a 1-degree scale (EPSG:4326) is applied to the result. 1 degree at the equator is approximately 111 kilometers, which matches the result you received.

For more information, see the Projections section of the Earth Engine documentation.

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