Description
Convert GPS day-of-week and uniform-day seconds to seconds from GPS week start.
Geodesy distinguishes a mathematical reference ellipsoid, a realized coordinate datum and the physical gravity field. Geodetic latitude follows the ellipsoid normal; geocentric latitude follows a radius from the center. Ellipsoidal height, orthometric height and geoid undulation are separate signed quantities. Keep the declared ellipsoid, coordinate axes, angular units and time scale with a result.
Convert GPS day-of-week and uniform-day seconds to seconds from GPS week start.
When to use this tool
Use this tool when you need to convert GPS day-of-week and uniform-day seconds to seconds from GPS week start.
How to use the tool and how it works
- Enter gpsDayOfWeek, secondsOfDay using the definitions below.
- Run the operation. Resolve input-format errors before interpreting an output.
- Read result.secondsOfWeek, using the stated boundary, ordering, sign and absence conventions.
Calculate gpsDayOfWeek×86,400+secondsOfDay under a seven-day GPS week.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| gpsDayOfWeek | Integer GPS day index zero through six; zero is Sunday. | Finite safe integer satisfying the stated bounds. |
| secondsOfDay | Seconds elapsed in the GPS day, 0≤seconds<86,400. | Finite numeric value satisfying the stated comparisons. |
| Output field | Interpretation |
|---|---|
| result | Object containing the fields below. |
| result.secondsOfWeek | GPS seconds from week start, within [0,604,800). |
{
"input": {
"gpsDayOfWeek": 2,
"secondsOfDay": 3600
},
"output": {
"result": {
"secondsOfWeek": 176400
}
}
}Limitations and assumptions
- Day is an integer zero through six, with zero denoting Sunday, and secondsOfDay lies in [0,86,400). This arithmetic does not convert GPS time to UTC or handle a leap-second day.
- All quantities are finite and retain the units stated for this operation. Ellipsoid-parameter tools use semi-major axis 1–10⁸ m and dimensionless flattening 0–0.02; explicit-axis tools use 0.9a≤b≤a unless a tighter bound is stated. These tools do not fetch datums, geoid grids, satellite observations or Earth-orientation updates.
- Every declared outer field is required and unknown outer fields are rejected. Strings and JSON text have size limits, lists are bounded to 128 entries, and JSON nesting/node counts are bounded. Tighter operation-specific bounds stated above take precedence.
- Numeric results must be finite. Large physical magnitudes are allowed by the output evidence checks, while integer fields and source schemas retain their exactness rules. Source indexes are zero-based. Floating-point residues can remain even where an ideal formula gives an exact zero.
Alternative or Complementary methods
Use a coordinate transform for a change of representation and explicit datum parameters for a change of reference frame. Preserve model and convergence metadata, and use observation and datum information appropriate to a real survey before interpreting a computed tolerance as accuracy.
References
Similar or alternative tools
- GPS Week Number rollover Check Calculator
Resolve a GPS week remainder against a nearby full-week reference, rejecting half-period ambiguity.
- Julian Date from Calendar Date Standard Converter
Convert a proleptic Gregorian date and uniform-day seconds to fractional Julian day.