References
GNSS specifications and algorithm references.
Use these primary specifications, institutional explanations and research papers to check a format definition or understand the method behind a calculation. Each entry points to the lessons where it is most useful. A source’s version and assumptions matter: a real RINEX 3.02 epoch, a RINEX 3.04 format example and a synthetic ambiguity vector serve different teaching purposes.
Observation and precise orbit formats
RINEX 3.02 specification (opens in a new tab)
IGS RINEX Working Group and RTCM-SC104 · 2013 · PDF
Defines the observation codes, units, time tags and navigation records used in the Double Difference lesson’s RINEX 3.02 input files.
RINEX 3.04 specification (opens in a new tab)
IGS RINEX Working Group and RTCM-SC104 · Version 3.04 · PDF
Use the format tables to verify observation headers, constellation-specific column order, epoch records and measurement fields in the RINEX basics lesson.
IGS RINEX Working Group (opens in a new tab)
International GNSS Service · specification archive and version history
Find other RINEX versions and their changes. Match the specification to the file’s declared version rather than assuming every example uses the newest format.
The Extended Standard Product 3 Orbit Format (SP3-d) (opens in a new tab)
Steve Hilla, NOAA National Geodetic Survey · 2016 · IGS-hosted PDF
Check precise orbit header records, satellite position and clock fields, units and the extensions introduced by SP3-d. The interpolation lesson explains how stored epochs become a coordinate at the required time.
GPS time, broadcast models and atmospheric corrections
IS-GPS-200, Revision N (opens in a new tab)
GPS space segment / navigation user interfaces · August 2022 · PDF
The GPS interface specification defines broadcast navigation parameters and the associated user algorithms. Consult it for satellite clock, ephemeris and ionospheric model conventions.
Time References in GNSS (opens in a new tab)
J. Sanz Subirana, J. M. Juan Zornoza and M. Hernández-Pajares · ESA Navipedia · 2011
Distinguishes GPS time from UTC and the time scales of other constellations. Use it to understand why a calendar timestamp needs an explicit time-scale convention.
Klobuchar Ionospheric Model (opens in a new tab)
J. Sanz Subirana, J. M. Juan Zornoza and M. Hernández-Pajares · ESA Navipedia · 2011
Explains the broadcast single-frequency ionospheric model, its coefficients and the semicircle-to-radian convention needed when evaluating its equations.
Tropospheric Delay (opens in a new tab)
ESA Navipedia · atmospheric model overview · 2011
Explains hydrostatic and wet delay, elevation dependence and the different meteorological assumptions behind tropospheric models. Use it for context when interpreting a Saastamoinen correction.
Least squares, geometry and relative positioning
Parameters adjustment (opens in a new tab)
ESA Navipedia · least-squares estimation
Describes estimation from a linear observation model and its statistical assumptions. Relate the general adjustment equations to the design matrices and weighted residuals in the worked lessons.
Positioning Error (opens in a new tab)
ESA Navipedia · covariance and dilution of precision
Defines DOP from satellite geometry and distinguishes ECEF covariance from its local east–north–up representation. Horizontal and vertical DOP require the local frame.
RTK Fundamentals (opens in a new tab)
Edited by GMV · ESA Navipedia · 2011
Introduces base–rover architecture, simultaneous double differences and carrier-phase ambiguity estimation. It gives broader operational context for the site’s single-epoch baseline example.
Carrier Phase Ambiguity Fixing (opens in a new tab)
J. Sanz Subirana, J. M. Juan Zornoza and M. Hernández-Pajares · ESA Navipedia · 2011
Explains the integer nature of double-differenced carrier ambiguities and the distinction between differenced and undifferenced ambiguity models.
LAMBDA, MLAMBDA and ambiguity evaluation
The least-squares ambiguity decorrelation adjustment: a method for fast GPS integer ambiguity estimation (opens in a new tab)
P. J. G. Teunissen · Journal of Geodesy 70, 65–82 · 1995 · DOI: 10.1007/BF00863419
The original LAMBDA journal paper establishes the decorrelation and integer least-squares method. Use it for the theoretical foundation; the Qelora lesson documents a particular practical execution.
MLAMBDA: a modified LAMBDA method for integer least-squares estimation (opens in a new tab)
X.-W. Chang, X. Yang and T. Zhou · Journal of Geodesy 79, 552–565 · 2005 · author-hosted PDF
Describes reduction and search modifications for efficient integer least-squares estimation. It supplies implementation context for the RTKLIB-style MLAMBDA family described in the lesson.
New LAMBDA toolbox for mixed-integer models: estimation and evaluation (opens in a new tab)
L. Massarweh, S. Verhagen and P. J. G. Teunissen · published 2024, GPS Solutions 29, article 14 (2025) · open access
Provides further reading on integer estimation, validation and success-rate evaluation. This is a separate toolbox reference; it is not the implementation used to generate the site’s teaching exports.
Inspect the lesson’s own numerical sources
The references above explain formats and methods. The lesson downloads show the inputs and outputs of the particular examples used here. Follow the provenance notes when reproducing a number, and keep formal covariance, residual diagnostics and independent accuracy checks separate.