How to read A/B codes
Quick start (3 steps)
- Enter location, date/time, timezone, and target Right Ascension and Declination (RA/Dec).
- Click Compute to get Altitude and Azimuth (Alt/Az) at the selected time.
- Inspect 24h curve and export CSV if needed.
Inputs
Results
| Alt (deg) | — |
|---|---|
| Az (deg, N=0 E=90) | — |
| Hour Angle (HA) (hms) | — |
| LST (hms) | — |
| Air mass | — |
| Resolved TZ | — |
This tool runs in your browser. Inputs are not sent. Geometric altitude (no refraction correction).
24h altitude curve
Interpretation & notes
- Azimuth is normalized to 0..360 with north=0, east=90.
- Airmass is shown only when altitude is above the horizon.
- CSV columns: local/UTC timestamps + coordinates + Alt/Az + air mass.
How to use this calculator effectively
This guide helps you use RA/Dec to Alt/Az calculator + daily altitude curve in a repeatable way: define a baseline, change one variable at a time, and interpret outputs with explicit assumptions before you share or act on results.
How it works
The page applies deterministic logic to your inputs and shows rounded output for readability. Treat it as a comparison workflow: run one baseline case, adjust a single parameter, and measure both absolute and percentage deltas. If a result seems off, verify units, time basis, and sign conventions before drawing conclusions. This approach keeps your analysis reproducible across teammates and sessions.
When to use
Use this page when you need a fast estimate, a classroom check, or a practical what-if comparison. It works best for planning and prioritization steps where you need direction and magnitude quickly before investing in deeper modeling, manual spreadsheets, or formal external review.
Common mistakes to avoid
- Changing multiple parameters at once, which hides the true cause of output movement.
- Mixing units (percent vs decimal, monthly vs yearly, gross vs net) across scenarios.
- Comparing with another tool without aligning defaults, constants, and rounding rules.
- Using rounded display values as exact downstream inputs without re-checking precision.
Interpretation and worked example
Run a baseline scenario and keep that result visible. Next, modify one assumption to reflect your realistic alternative and compare direction plus size of change. If the direction matches your domain expectation and the size is plausible, your setup is usually coherent. If not, check hidden defaults, boundary conditions, and interpretation notes before deciding which scenario to adopt.
See also
FAQ
Why does azimuth wrap around 360°?
Azimuth is normalized to 0..360°. The jump is a wraparound of the circular range, not a physical discontinuity.
Why is air mass hidden at low altitude?
Air mass is not defined below the horizon. The tool hides that value and continues to show altitude and azimuth for context.
What should I do first on this page?
Start with the minimum required inputs or the first action shown near the primary button. Keep optional settings at defaults for a baseline run, then change one setting at a time so you can explain what caused each output change.
Why does this page differ from another tool?
Different pages often use different defaults, units, rounding rules, or assumptions. Align those settings before comparing outputs. If differences remain, compare each intermediate step rather than only the final number.
How reliable are the displayed values?
Values are computed in the browser and rounded for display. They are good for planning and educational checks, but for regulated or high-stakes decisions you should validate assumptions with official guidance or professional review.