Sentinel-1 HH band not loading in Google Earth Engine

Question

While importing the VV band in Sentinel-1 datasets from GEE, there is no problem when I use the following lines:

var collection = ee.ImageCollection('COPERNICUS/S1_GRD')
    .filterBounds(dam_basin)
    .filter(ee.Filter.listContains('transmitterReceiverPolarisation', 'VV'))
    .filter(ee.Filter.eq('instrumentMode', 'IW'))
    .select('VV');

But replacing the 'VV' with 'HH' leads to the errors in the subsequent lines which worked with 'VV'. The next lines is just thresholding with values less than -14dB.

Answer 1

Your study region is likely located outside of sea-ice regions and the polar environments, where HH images are acquired. For the remaining land-surface areas the standard dual polarisation mode is VV+VH.

HH is generally only used for sea-ice detection and in polar regions.

See also the documented Sentinel-1 observation scenario