Diffuse radiation formula (Heat Overlay)
The diffuse radiation is an input parameter for the PET-formula
The diffuse radation Qd at time t is calculated using the following formula:
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Q_{d,t} = Q_{gl,t} * f_{transmission,t}}
where,
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Q_{gl,t}} is the amount of sun radiation at time t, measured at a weather station.
- is the atmospheric transmission factor at time t.
Atmospheric transmission factor
The atmospheric transmission factor ftransmission,t is calculated as followed:
| ftransmission,t | Condition |
|---|---|
| 1 | τa <= 0.3 |
| 1.6-2* τa | 0.3 < τa < 0.7 |
| 0.2 | τa >=0.7 |
where τa is the atmospheric transmissivity. This is calculated as:
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \tau_{a} = \frac{Q_{gl,t}}{1367 \cdot \sin(\phi_t)}}
where,
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Q_{gl,t}} is the amount of sun radiation at time t, measured at a weather station.
- Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \phi_{t}} is the sun altitude angle in ° at time t.
