Earth-Moon-Earth or exotic digital modes are also a possibility. EME is impossible to triangulate if you're using a suitably directional antenna. A creative int

Earth-Moon-Earth or exotic digital modes are also a possibility. EME is impossible to triangulate if you're using a suitably directional antenna. A creative interpretation of the Shannon-Hartley theorem allows for communication below the noise floor using low symbol rates and wide bandwidth. LF and below is difficult to triangulate because of the huge wavelengths, but a workable antenna would be rather conspicuous. You might also get lucky with meteor scatter or sporadic E.