1. A method comprising: obtaining, at a device, a set of signal measurements based on a radio frequency (RF) signal transmitted by a RF signal source; applying a window function to the set of signal measurements to obtain a subset of signal measurements; obtaining a probability density function for the subset of signal measurements; obtaining a cumulative distribution function of the subset of signal measurements from the probability density function; defining a plurality of range classes based on the cumulative distribution function and an RF signal propagation model, where each range class includes a percentage of the subset of signal measurements; processing the range classes in a specified order until a range class is identified from the plurality of range classes that includes a threshold percentage of signal measurements, where the first range class processed represents a closest distance to the RF signal source; responsive to identifying the range class that includes the threshold percentage of signal measurements, designating the identified range class as a range class observation; and obtaining an estimated range class using the range class observation, where the method is performed by one or more processors.