Thoughts On Shortwave Radio

1. Shortwave Radio Emissions Basics

• Shortwave (HF) radio waves are electromagnetic signals that can travel globally by bouncing off the ionosphere (Earth's upper atmosphere). They're commonly used for international broadcasting, amateur radio, and emergency communications.
• "Emission within soft medium intensity" could refer to controlled, moderate-power shortwave signals in a "soft" environment:
  • In medical contexts, shortwave diathermy uses HF waves (around 27 MHz) at low-to-medium intensity to heat soft tissues for therapy, improving blood flow without damaging skin. This is ground-based equipment, not satellite-related.
  • In propagation terms, shortwave can interact with "soft" media like atmosphere or water vapor, but intensity (power level) is regulated to avoid interference—typically 10–100 kW for broadcasters.
• No direct link to satellites here, as shortwave is primarily terrestrial.

2. Satellites in Orbit and Shortwave Radio

• Orbital satellites generally use higher frequencies (VHF, UHF, microwave) for communication because shortwave signals from space are often absorbed or refracted by the ionosphere, making ground reception unreliable. However, there are some related phenomena:
  • Unintended Emissions: Modern satellite constellations like Starlink emit low-level radio noise in frequencies overlapping with shortwave or nearby bands (e.g., 110–188 MHz, which is VHF but close). This "leakage" interferes with radio astronomy and ground-based observations. Second-generation Starlink satellites reportedly leak 30 times more unintended radiation than earlier models.
  • Observations from Space: Satellites can detect terrestrial shortwave noise. For example, Earth's man-made shortwave signals are 10 times stronger near our planet than at the Moon or L1 point, creating interference for space-based radio telescopes. Variations in this noise have been studied over 19 years using satellite data.
  • Experimental Transmissions: There have been space-to-space tests with very low frequency (VLF, below shortwave) radio in the magnetosphere, but not routine shortwave emissions. The International Space Station (ISS) doesn't significantly disturb shortwave reception, despite orbiting within the ionosphere.
• Overall, intentional shortwave emission from orbit is rare and impractical for most applications.

3. "Satellites Planted in Earth Soil" and Related Ground Systems

• This phrasing doesn't align with standard terminology—satellites orbit space, not soil. It might refer to ground-penetrating sensors or buried devices networked with orbital satellites for data relay. Related tech includes:
  • Soil Moisture Monitoring: Satellites like NASA's Soil Moisture Active Passive (SMAP) use microwave radar (L-band, 1–2 GHz—not shortwave) to measure soil moisture from orbit. Ground sensors "planted" in soil collect local data, which is validated against satellite observations for agriculture and climate modeling.
  • Remote Sensing Networks: Systems combine buried soil probes (for moisture, nutrients) with satellites for wide-area mapping. For instance, NASA's GRACE satellites track groundwater via gravity changes, paired with ground sensors. No shortwave involved; they use higher frequencies or passive sensing.
  • Radio in Soil: Shortwave doesn't penetrate soil well (high attenuation in "soft" damp media), so ground-penetrating radar uses UHF or lower frequencies. Intensity must be low to avoid heating or interference.

4. Potential Combined Systems (Hypothetical Interpretation)

• If your query envisions a hybrid setup—shortwave emitters in soil (e.g., buried antennas) relaying to orbital satellites—that's not a real technology. Shortwave antennas are large and surface-mounted; burying them would dampen signals severely.
• In environmental monitoring, satellites like NISAR (NASA-ISRO Synthetic Aperture Radar) map soil and crops using radar, potentially at medium intensity for precision without overwhelming ground systems. Ground "planted" sensors could use low-power radio (not shortwave) to upload data to satellites.
• For space weather or ionospheric studies, ground HF transmitters (like HAARP) emit shortwave to heat the atmosphere, with satellites monitoring effects. Intensity is controlled (medium levels for research), but no soil-planting involved.