Learning path
A guided sequence from raw observations to positioning.
Follow the prerequisite chain from time, raw observations, satellite orbits, corrections and geometry to SPP. Then learn integer ambiguity resolution with LAMBDA before applying it to a relative baseline in Double Difference.
Module 1
Foundations
Time tags and the minimum coordinate context needed before reading GNSS files.
Step 1 - Fundamentals
GPS Time Conversion
Convert a GPS-time calendar timestamp into Julian Date and GPS seconds-of-week.
Module 2
Observations and Files
RINEX observation rows, navigation records, and precise orbit file anatomy.
Step 2 - Fundamentals
RINEX Observation Basics
Read the header, observation types, epoch lines, and satellite measurement rows.
Module 3
Satellite Orbits and Ephemerides
The orbit side of SPP: Keplerian elements, broadcast propagation, and SP3 interpolation.
Step 3 - Fundamentals
Keplerian Elements in GPS Navigation Messages
Read broadcast ephemeris parameters before using them in satellite position computation.
Step 4 - Intermediate
Satellite Position from Broadcast Ephemeris
Propagate a GPS navigation record to an ECEF satellite coordinate.
Step 5 - Intermediate
SP3 Interpolation
Read precise orbit files and interpolate satellite coordinates to observation time.
Module 4
Corrections
Atmospheric and hardware corrections that turn raw code ranges into a cleaner model.
Step 6 - Intermediate
Klobuchar Ionospheric Correction
Compute the GPS L1 ionospheric slant delay from broadcast alpha and beta coefficients.
Step 7 - Intermediate
Saastamoinen Tropospheric Delay
Compute hydrostatic and wet neutral-atmosphere delay for a GNSS signal path.
Module 5
Geometry and Quality
Satellite geometry, error amplification, covariance, and practical accuracy interpretation.
Step 8 - Intermediate
ECEF to ENU: Coordinates and Covariance
Rotate a position offset and its full covariance into local east, north and up.
Step 9 - Intermediate
DOP Calculation
Turn satellite geometry into GDOP, PDOP, HDOP, VDOP, and TDOP.
Module 6
Positioning Algorithms
The complete numerical path from observations and navigation data to a receiver solution.
Step 10 - Intermediate
SPP from Scratch
Assemble the complete GPS single point positioning chain from C1C observations.
Module 7
Advanced Positioning
Carrier-phase ambiguity resolution and precise positioning after the SPP foundation.
Advanced tutorial - Published
LAMBDA Method
Integer ambiguity decorrelation and search for high-precision carrier-phase GNSS.
Advanced tutorial - Published
Double Difference from Scratch
Trace real RINEX observations through single and double differences, covariance, QR weighted least squares, LAMBDA and a candidate-fixed baseline.