Regarding the issue of data projection coordinate system and spatial resolution in Google Earth Engine

[AomineKai]

Dear Professor Wu，Hello！

I'm getting inconsistent results when querying the spatial resolution using these two methods: one shows 111319.49079327357 and the other shows 1. Why isn't the spatial resolution 30 meters?

// 加载并计算 Landsat 8 SR 影像中值数据
var landsat = ee.ImageCollection('LANDSAT/LC08/C02/T1_L2')
.filterBounds(region)
.filterDate(startDate, endDate)
.median();

// 查询投影信息
var projection = landsat.projection();
print("投影信息：", projection);

// 查询空间分辨率
var scale = projection.nominalScale();
print("空间分辨率：", scale);

// 定义投影系统
var crs = 'EPSG:3857';

// 投影 Landsat 8 影像到 EPSG 3857
var landsatProjected = landsat
.reproject({
crs: crs
});

// 查询投影信息
var projection = landsatProjected.projection();
print("投影信息：", projection);

// 查询空间分辨率
var scale = projection.nominalScale();
print("空间分辨率：", scale);

[giswqs]

The default spatial resolution of computational results will be 1 degree (~111319 m). No need to worry about spatial resolution unless you need to export the data.