Why optics is not enough
Foo Fighter testimony about instruments, compasses and radios motivates an EM hypothesis. A strong future event would combine optical red/orange emission, spectrum, EM/RF anomaly, no ADS-B/TLE/meteor match, audio without motor and at least two stations.
| Sensor | Measures | Approximate useful range |
|---|---|---|
| Visible camera | Red/orange orb when lit. | 2-20 km or more with optics and line of sight. |
| Spectrum / H-alpha | H, Na, N2/OH lines; non-thermal emission confirmation. | 0.2-3 km without telescope; more if bright. |
| Magnetometer | Peaks, vector rotation, microtesla/nanotesla anomalies. | Tens of meters to a few km depending on field strength. |
| Field mill / electric field | Gradient shifts, pulses, inversion. | Hundreds of meters to km only if external field is strong. |
| SDR/RF | Bursts, broadband noise, interference. | 1-50 km if RF is emitted; urban noise limited. |
| Ozone/NOx/ions | Local plasma/corona chemistry. | Close range, likely tens of meters. |
| Audio | Reject rotor/turbine/drone. | Environment dependent but critical as negative evidence. |