A17.6.2.2 Input parameters
Figure 476: SEAMCAT Interface to the ITU-R P.452-16 model
Table 83: ITU-R P.452-16 propagation model
Description | Symbol | Type | Unit | Comments |
Variation | - | boolean | - | Variation in path loss. |
Diffraction only | - | boolean | - | Select to compute only the diffraction component of the propagation model |
Water concentration | ρ | S | g/m3 | water vapour density (default 3 g/m3) |
Surface pressure | P | S | hPa | Surface pressure |
Refraction index gradient | ΔN | S | 1/km | The average radio-refractive index lapse-rate through the lowest 1 km of the atmosphere, provides the data upon which the appropriate effective Earth radius can be calculated. Note that ΔN is a positive quantity. |
Surface temperature | T | S | Degree Celsius | Surface temperature |
Latitude | S | Degree | Latitude of the path-centre location between Tx and Rx | |
Antenna gain at the Tx | Gt | S | dB | Antenna gain of the Tx in the direction of the horizon along the great-circle interference path (dBi) |
Antenna gain at the Rx | Gr | S | dB | Antenna gain of the Rx in the direction of the horizon along the great-circle interference path (dBi) |
Sea level surface refractivity | N0 | S | - | The sea-level surface refractivity used by the troposcatter model as a measure of location variability of the troposcatter scatter mechanism. The correct values of ΔN and N0 are given by the path-centre values as derived from the appropriate maps. |
Time Percentage | p | D | % | Percentage time variability for which the basic transmission loss is not exceeded. |
Local clutter conditions at Tx/Rx |
| Predefined set of clutter (ground-cover) categories that the user can choose from: Suburban, Dense suburban, Urban, Dense urban, High-rise urban, and Industrial zone. | ||
User specified clutter nominal heights at Tx/Rx | ha_t, ha_r | S | m | Clutter nominal heights specified by user if different from above |
User specified clutter nominal distance from Tx/Rx | dk_t, dk_r | S | m | Nominal clutter distances from Tx/Rx antenna, specified by user if different from above |