Zero elements in my ImageCollection

Question

I'm trying to obtain Sentinel-1 images in Google eart hengine and to have 3 different imagecollections: 1. HV 2.HH 3.VV I have written the following code but whenever I check my image collection it has 0 elemnts. I know that there are images on the chosed period. what can be the reason? where is my mistake? I'ts important to mention that in the following code, everytime I used "print" in order to check my image collectio, I have gotten 0.

// Load the Sentinel-1 ImageCollection.
var sentinel1 = ee.ImageCollection('COPERNICUS/S1_GRD');

// Filter by metadata properties.
var dataset = sentinel1
  // Filter to get images with VV and VH dual polarization.
  .filter(ee.Filter.listContains('transmitterReceiverPolarisation', 'VV'))
  .filter(ee.Filter.listContains('transmitterReceiverPolarisation', 'HH'))
  .filter(ee.Filter.listContains('transmitterReceiverPolarisation', 'HV'))
  // Filter to get images collected in interferometric wide swath mode.
  .filter(ee.Filter.eq('instrumentMode', 'IW'))
  .filterBounds(geometry);

// Filter to get images from different look angles.
var descending = dataset.filter(ee.Filter.eq('orbitProperties_pass', 'DESCENDING'));

print(descending);
//Filter dates
var dateDesc = descending.filterDate(ee.Date('2018-10-01'),ee.Date('2019-10-08'));

print(dateDesc);

//clip the dataset according to the geometry
var clippedCol=dateDesc.map(function(im){ 
  return im.clip(geometry);
});

var HV=clippedCol.select('HV');
var HH=clippedCol.select('HH');
var VV=clippedCol.select('VV');
print(HV);

I have also tried this code but again , got 0 elements:

// Load the Sentinel-1 ImageCollection.
var sentinel1 = ee.ImageCollection('COPERNICUS/S1_GRD');

// Filter VH, IW
var HV = sentinel1
  // Filter to get images with VV and VH dual polarization.
  .filter(ee.Filter.listContains('transmitterReceiverPolarisation', 'HV'))
  // Filter to get images collected in interferometric wide swath mode.
  .filter(ee.Filter.eq('instrumentMode', 'IW'))
  // reduce to VH polarization
  .select('HV')
  // filter 10m resolution
  .filter(ee.Filter.eq('resolution_meters', 10))
  .filterBounds(geometry);
// Filter to orbitdirection Descending
var HVdescending = HV.filter(ee.Filter.eq('orbitProperties_pass', 'DESCENDING'));
// Filter time 
var HVdate = HVdescending.filterDate(ee.Date('2015-08-01'), ee.Date('2019-10-08'));


// Load the Sentinel-1 ImageCollection.
var sentinel1 = ee.ImageCollection('COPERNICUS/S1_GRD');

// Filter HH, IW
var HH = sentinel1
  // Filter to get images with VV and VH dual polarization.
  .filter(ee.Filter.listContains('transmitterReceiverPolarisation', 'HH'))
  // Filter to get images collected in interferometric wide swath mode.
  .filter(ee.Filter.eq('instrumentMode', 'IW'))
  // reduce to VH polarization
  .select('HH')
  // filter 10m resolution
  .filter(ee.Filter.eq('resolution_meters', 10))
  .filterBounds(geometry);
// Filter to orbitdirection Descending
var HHdescending = HH.filter(ee.Filter.eq('orbitProperties_pass', 'DESCENDING'));
// Filter time 
var HHdate = HHdescending.filterDate(ee.Date('2015-08-01'), ee.Date('2019-10-08'))


// Load the Sentinel-1 ImageCollection.
var sentinel1 = ee.ImageCollection('COPERNICUS/S1_GRD');

// Filter VH, IW
var VV = sentinel1
  // Filter to get images with VV and VH dual polarization.
  .filter(ee.Filter.listContains('transmitterReceiverPolarisation', 'VV'))
  // Filter to get images collected in interferometric wide swath mode.
  .filter(ee.Filter.eq('instrumentMode', 'IW'))
  // reduce to VH polarization
  .select('VV')
  // filter 10m resolution
  .filter(ee.Filter.eq('resolution_meters', 10))
  .filterBounds(geometry);
// Filter to orbitdirection Descending
var VVdescending = HV.filter(ee.Filter.eq('orbitProperties_pass', 'DESCENDING'));
// Filter time 
var VVdate = VVdescending.filterDate(ee.Date('2015-08-01'), ee.Date('2019-10-08'))


print(VVdate);
print(HVdate);
print(HHdate);

Answer 1

The instrumentMode for HH-HV or HV is EW and not IW. Also, there is no 10m resolution available for these polarizations.

To make sure you pick your geometry right:

• HH-HV or HH polarization for the monitoring of polar environments, sea-ice zones
• VV-VH or VV polarization for all other observation zones (with an exception for the Baltic Sea observed partially in HH-HV with Sentinel-1B during northern winter) (source)

Apart from that, you were filtering for Descending pass on the wrong collection for VV.

Here is the full code for all the three collections (making sure you pick the right geometry for the respective polarization):

https://code.earthengine.google.com/ad5ff7642908d3fb99446cc04b96a528