Error : no picture for geemap.landsat_timeseries in china

[Liluoq]

when I'm using the function geemap.landsat_timeseries to visualize the lake's area changes in china, it occurs that all the band's value goes to be None.

[Liluoq]

rect = ee.Geometry.Polygon([[90.6927, 32.2146], [91.0450, 32.2118], [91.0457, 31.9348], [90.6934, 31.9313]])
rect_fea=ee.FeatureCollection(rect)
collection = geemap.landsat_timeseries(roi=rect, start_year=1985, end_year=2019, start_date='06-10', end_date='09-20', apply_fmask=False)
first_image = collection.first()

vis = {
'bands': ['NIR', 'Red', 'Green'],
'min': 0,
'max': 4000,
'gamma': [1, 1, 1]
}
print(collection.size().getInfo())

Map.addLayer(first_image, vis, 'First image')

[ErikSeras]

Apparently there are no satellite images in that area in 1985. Try running tests starting in 1986.

Map = geemap.Map()

rect = ee.Geometry.Polygon(
    [[
      [90, 33],
      [92, 33],
      [92, 31],
      [90, 31],
      [90, 33]
    ]], None, False
)

# rect_fea=ee.FeatureCollection(rect)
collection = geemap.landsat_timeseries(
    roi=rect, start_year=1986, end_year=2019,
    start_date='06-10', end_date='09-20', apply_fmask=False
)

first_image = collection.first()

vis = {
'bands': ['NIR', 'Red', 'Green'],
'min': 0,
'max': 4000,
'gamma': [1, 1, 1]
}
# print(collection.size().getInfo())

Map.centerObject(first_image, zoom=10)
Map.addLayer(first_image, vis, 'First image')
Map

[Liluoq]

Many thanks!!!