Measure river width using GEE

Question

I am trying to measure river width using GEE, but everytime this error coming up

Feature collection( error)

Image.clip: Parameter 'input' is required.

// Goal: calculate river centerlines and widths for one Landsat 

// load in RivWidthCloud
var fns = require('users/eeProject/RivWidthCloudPaper:rwc_landsat.js');

// assign the image id of the image from which the widths and centerline will be extracted
var imageId = "LANDSAT/LE07/C02/T1_L2/LE07_139043_20170616";

print(imageId);
 
// setting the parameters for the rivwidthcloud (rwc) function
var aoi = ee.Geometry.Polygon(
        [[[87.03177053763748, 23.81382559855354],
          [87.03177053763748, 23.027480838211885],
          [87.1084104302156, 23.027480838211885],
          [87.108104302156, 23.81382559855354]]], null, false);
var rwc = fns.rwGenSR('Jones2019', 4000, 333, 500, aoi);


// apply the rwc function to the image
var widths = rwc(imageId);

// remove the geometry before exporting the width as CSV file
widths = widths.map(function(f) {return(f.setGeometry(null))});
print(widths);

// export the result as a CSV file into Google drive
Export.table.toDrive({
  collection: widths,
  description: imageId,
  folder: "",
  fileNamePrefix: imageId,
  fileFormat: ""});

Answer 1

You are asking for an Image (LANDSAT/LE07/C02/T1_L2/LE07_139043_20170616) that is not supported by that older version RivWidthCloudPaper library:

1. You are asking for collection 2 data ("C02") and the module only handles collection 1 "C01" images (source). However, collection 1 data is no longer available in GEE, and

2. The module filters out any post-2003 SLC-OFF Landsat 7 (source) and you are asking for 2017 Landsat 7.

If you want to use this algorithm, you'll need to:

1. follow the instructions here to use an updated module that supports collection 2 data, i.e.

   var fns = require('users/eeProject/RivWidthCloudPaper:rwc_landsat_C2.js');
   

2. specify Landsat 8 imagery if you want 2017 data.