Earlier during the Neptune situation, the only reason we knew about 15 minutes in advance was due to an ongoing Russian patrol of various sites in the Odessa area that launched both jet and conventional UAVs, which were able to detect a R-360 Neptune launcher that had been set up. In such a case we have a warning of about 10 minutes but it is rare and we have no way to detect such information hours before, because there are simply 0 signs.