Table 3.
Terms included in REASON 1D link budget
| Link Budget Term | Description | Relevant Regimes | Reference | |
|---|---|---|---|---|
| Performance, Operations, Geometry | Radar Potential | SNR of a flat, perfect, infinite reflector at a range of 400 km, assuming SAR processing | – | Sect. 4.4.1 |
| Reference SAR Gain | Gain resulting from SAR processing at the reference altitude (400 km) | – | Sect. 4.4.4 | |
| Reference SAR Gain is subtracted from Radar Potential so that SAR Gain can be recalculated for the altitude of interest | ||||
| Geometric Spreading | Loss due to spreading of the wavefront, calculated with respect to the reference altitude (400 km) | – |
Schroeder et al. (2014) Haynes et al. (2018b) |
|
| Flat Europa Assumption | Loss to account for a spherical (as opposed to flat) Fresnel zone area | – | Haynes et al. (2018b) | |
| Short Chirp | Loss associated with a chirp length (RF pulse width) below the 200 μs assumed in deriving the radar potential | – | Table 9 | |
| SAR Gain | Gain resulting from SAR processing (not applied for Reflectometry) | – | Peters et al. (2005b) | |
| 1-Bit Sampling | Loss (VHF only) resulting from recording only the signal sign below 3 km to conserve data volume | – | Scanlan et al. (2020) | |
| Infinite Mirror Assumption | Loss to account for spherical (as opposed to flat) wavefront | – | Haynes et al. (2018b) | |
| Range Side Lobe Noise | Loss due to side lobes (Hann processing window) | – | Sect. 4.4.5 | |
| Europa | Surface Scattering | Loss to due signal scattering from a rough surface | Surface Roughness | Fung et al. (1992) |
| Surface Transmission | Loss to due signal transmission through a rough surface | Surface Roughness | Fung et al. (1992) | |
| Volume Scattering | Loss due to volume scattering from voids in the ice shell | Deep Regolith | Aglyamov et al. (2017) | |
| Ice Shell Attenuation | Loss due to electrical conductivity of the ice shell | Surface Temperature | Moore (2000) | |
| Ice Shell Composition | ||||
| Ice Shell Thickness | ||||
| Basal Temperature | ||||
| Interface Reflection Coefficient | Fresnel reflection coefficient at the target interface | Near-Surface Density | Mouginot et al. (2009) | |
| Near-Surface Composition | ||||
| Near-Surface Thickness | ||||
| Salt Layer Thickness | ||||
| Salt Layer Depth | ||||
| Subsurface Water Interface |