“The US Navy has secret mine detectability from Space Force using water penetrating radar.”
Who taught you physics they failed.
Radio above VLF or ELF cannot penetrate salt water due to the dielectric effect. Microwave penetrate inches at most.
Lasers in the blue green spectrum can reach 30-50 meters in clear offshore waters and 10-15 in the littorals. With single digit photon counting detection, tight spectral filtering and being airborne not in space but directly above it in a helo you can reach down triple digit feet the exact amount is classified. Space based won’t work the round trip losses are 180+ Dbi even with Hubble space telescope sized receiver optics the path losses are just too much for imaging underwater via laser backscatter. One way communication space to water theoretically possible as the water filters all the other portions of the light spectrum out at depth so you can detect single digit photons inbound.
One of my master’s is in remote sensing and Geointelligence at the post grad level from the NGA.
There is work being done on using laser to induce sound pulses in water and then read the reflected waves off ripples in the surface of the water like you can use a laser.to listen to a window vibrating across a street doing spy stuff. The chances of it ever working for orbit are near zero, from 100 meters up via helo well that’s the question really.
Thank you for the elucidation.
I am pretty sure that mines can be detected by Space Force. I do not know the exact methods used.That ability comes from being able to detect submarines pretty much anywhere on the globe.
It may have to do with magnetic resonance anomaly (stochastic resonance method).
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Stochastic resonance (SR) is a signal processing method that uses noise energy to enhance signal energy, which has received extensive attention in recent years. Wan first applied the SR method to MAD, and the experimental results showed that the SR method had good performance and could be applied to the detection of non-periodic signals [25]. Sun optimized the structural parameters by using the marine predator algorithm, which improved the adaptability of the SR method to MAD [26]. Huang used the tri-stable stochastic resonance model to detect MAD signals under low signal-to-noise ratio (SNR) environments with strong background noise, which improved the detection probability [27]. Zhao proposed an adaptive pure background noise estimation method based on SR, which solved the problem that noise wavelet coefficients are difficult to separate from effective signals in existing wavelet domain denoising methods [28]. Liu proposed a detection strategy based on a parallel monostable SR (PMSR) system to solve the problem that MAD signals may be peak signals, trough signals, or a combination of the two in actual detection, which could ensure good detection performance for all kinds of MAD signals [29]. In addition, Wan also proposed that the MAD signal processing effect was easily affected by the initial value of the SR system in addition to structural parameters, so he proposed a parallel SR (PSR) method, which can detect MAD signals without prior information of target signal parameters and background noise [30]. This parallel SR system structure has also been used in the latest relevant research [31]. Dai proposed a MAD method that relies on a bi-stable SR system. The series dual system structure with different initial states was used to detect signals with different waveforms in real-time [32].
SR technology attracts our attention due to its ability to work without prior target information and its unique advantages in weak signal detection......
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https://www.sciencedirect.com/science/article/abs/pii/S0263224125012291