They are not looking for content, just the overall signal power.
They are looking at how the signal power changes in a way that fits the Gaussian curve they expect from receiving a signal that comes from another planet, that is the power goes up and down as the source planet revolves.
Once you identifed a signal as non natural you can spend the time to decode it.
It's not odd that the signal is not corrected, but it does show that the signal is being affected by the source's rotation, which you would expect from a transmitter on a planet but not so much from a stellar object.
Slashdot Mirror
They are not looking for content, just the overall signal power. They are looking at how the signal power changes in a way that fits the Gaussian curve they expect from receiving a signal that comes from another planet, that is the power goes up and down as the source planet revolves. Once you identifed a signal as non natural you can spend the time to decode it.
It's not odd that the signal is not corrected, but it does show that the signal is being affected by the source's rotation, which you would expect from a transmitter on a planet but not so much from a stellar object.