What Solar Elevation represents
The astronomical spherical relation gives the Sun's angle above the ideal horizon. Solar hour angle is zero at local solar noon, negative before noon, and positive after noon.
Solar Elevation begins with latitude, solar declination, solar hour angle. Mark each value as observed, remotely sensed, modeled, assumed, or derived, and preserve its valid time and spatial support.
Spatial and temporal representativeness
Cloud and visibility can change across seconds, kilometres, viewing directions, and vertical layers. One Solar Elevation input set represents only its declared path, footprint, and interval.
When combining several Solar Elevation samples, document weights and retain individual values so variability is not hidden by a single mean or total.
Where the model stops
Refraction near the horizon, elevation above sea level, parallax, solar-disc radius, and local obstructions matter for sunrise and shading decisions.
Solar Elevation is transparent educational arithmetic, not a cloud observation, weather forecast, solar-resource assessment, flight rule, runway visual range report, instrument calibration, or operational safety authority.
Cloud amount, overlap, and layers
Cloud fraction is an area or sky-dome proportion, while a ceiling is a height classification and optical depth is attenuation. Solar Elevation should not substitute one quantity for another merely because each relates to cloud.
When layers enter Solar Elevation, state whether overlap is random, maximum, observed, or ignored. Adding layer percentages directly can exceed 100% and double-count vertically aligned cloud.
Continue the Solar Elevation workflow with the related Clear-Sky Solar Radiation Calculator, keeping the same observation support and conventions.
Visibility and contrast conventions
Visibility from Solar Elevation depends on the target contrast threshold and extinction units. Meteorological optical range fixes a two-percent contrast convention; a general contrast range or runway screening estimate may use another threshold.
Do not equate Solar Elevation optical distance with prevailing visibility, slant range, night visual range, or official RVR without the required observation and processing conventions.
Solar geometry and radiation conventions
Solar elevation is measured above the geometric horizon, while azimuth here is clockwise from true north. Solar Elevation must retain whether radiation is normal to the rays or incident on a horizontal surface.
Civil time is not solar hour angle. Longitude, time zone, equation of time, atmospheric refraction, shading horizon, and surface tilt belong in Solar Elevation only when the displayed model explicitly includes them.
Formula and convention
The working relationship is α = asin(sinφ sinδ + cosφ cosδ cosH). Solar Elevation uses only the displayed entries and does not retrieve imagery, station observations, ephemerides, forecasts, or runway systems.
Keep percentages as percentages at entry and convert them to fractions only where the formula shows it. For Solar Elevation, retain angle direction, optical threshold, height reference, and distance unit with the answer.
Checked numerical example
At latitude 40°, declination 20°, and solar noon, elevation is exactly 70°.
Reset restores this Solar Elevation example. Repeat it independently with the stated constants and rounding before replacing demonstration values with observations or scenarios.
Collecting compatible inputs
Use geodetic latitude, solar declination for the date, and local solar hour angle rather than civil clock time. Longitude and equation-of-time corrections belong upstream.
Record site, coordinates, elevation, timestamp, time zone, path direction, wavelength or sensor band, target definition, cloud-layer method, solar-time convention, averaging period, and quality flags when relevant to Solar Elevation.
Interpreting Solar elevation angle
Positive elevation places the solar centre above the geometric horizon; negative elevation places it below. The result excludes atmospheric refraction and terrain horizon.
Compare Solar Elevation outputs only after aligning reference height, sky footprint, path, illumination, contrast convention, and temporal average. Similar numbers can describe different optical or geometric quantities.
Boundary and monotonic checks
Hour angle may span −180° to 180°. Polar day or night emerges from the geometry rather than a separate forecast.
For Solar Elevation, change one input at a time and predict whether the answer should rise, fall, or remain fixed. Unexpected behavior can expose percent-fraction, degree-radian, metre-kilometre, or layer-order mistakes.
Continue the Solar Elevation workflow with the related Cloud Ceiling Selection Calculator, keeping the same observation support and conventions.
Frequent clouds and visibility errors
Typical Solar Elevation errors include mixing oktas and tenths, confusing AGL with MSL, adding overlapping layers, treating degrees as radians, using sea-level-reduced visibility, or applying a two-percent constant to a five-percent threshold.
Reject impossible Solar Elevation combinations rather than forcing an answer. Keep a clear zero distinct from missing or obscured sky, preserve signs on hour angle, and verify every inverse distance and logarithm denominator before downstream use.
Cloud and visibility questions
Is this an operational visibility or aviation value?
No. Solar Elevation does not replace official weather observations, RVR systems, flight procedures, warnings, or qualified judgment.
How should the result be rounded?
Keep full precision inside Solar Elevation, then round no more finely than the least certain measurement or model assumption supports.
When should I recalculate?
Recalculate Solar Elevation when its site, time, path, layer, sky footprint, illumination, source observation, or model assumption changes.
What does Solar Elevation report?
Solar Elevation reports solar elevation angle from the displayed inputs and formula.