Knockout - Clone and Copy observableArray

HTML

<h1>array 1</h1>
<input data-bind="array1">

<h1>array 2</h1>
<input data-bind="array2">

JavaScript

var viewModel = (function() {
    var
        array1 = ko.observable('Test1'),
        array2 = ko.observable(array1()),
        array3 = ko.observableArray();


})();


    ko.applyBindings(viewModel);
    
    console.log(viewModel.array1());
    console.log(viewModel.array2());
    console.log(viewModel.array3());