I have a last-known reading from his internal transponder on the West coast at the following coordinates in California. Shortly after that, however, the transponder was disabled, rendering him invisible to most accessible satellite imagery I am able to access. I registered no internal log of distress or alarm before this occurred.
His unique brainwave signature on the other hand means that I can initiate a biological scan based on a specific search pattern around the area - though it may take me some time to render a likely location, taking into account relative population density and the variegated inhabitants of this world.