.. _file_interfaces_sp3_loader.h:

File sp3_loader.h
=================

|exhale_lsh| :ref:`Parent directory <dir_interfaces>` (``interfaces``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS



SP3 (precise GNSS ephemeris) file loader. 



.. contents:: Contents
   :local:
   :backlinks: none

Definition (``interfaces/sp3_loader.h``)
----------------------------------------


.. toctree::
   :maxdepth: 1

   program_listing_file_interfaces_sp3_loader.h.rst



Detailed Description
--------------------

Stanford NAV LAB 

0.1 

2025-06-07

Copyright (c) 2025

Parses IGS SP3 precise-ephemeris files and provides interpolated ECEF position / velocity / clock-bias queries. This is the C++ counterpart of ``pylupnt.interfaces.gnss_file_loader.SP3Loader`` (``python/pylupnt/interfaces/gnss_file_loader.py``); unlike the Python version can download/cache modern CDDIS SP3 files for requested epochs, or parse files that are already present on disk.

Position/velocity interpolation is provided by a per-satellite piecewise Chebyshev fit over the tabulated ECEF position and clock samples. Query-time velocity is the analytic derivative of the fitted position polynomial. 




Includes
--------


- ``filesystem``

- ``lupnt/core/constants.h``

- ``lupnt/core/definitions.h``

- ``lupnt/numerics/cheby_fit.h``

- ``map`` (:ref:`file_interfaces_maplot.cc`)

- ``string`` (:ref:`file_environment_plasma_core_string_file_utils.cc`)

- ``vector`` (:ref:`file_numerics_vector_macros.h`)



Included By
-----------


- :ref:`file_agents_gnss_constellation.cc`

- :ref:`file_interfaces_sp3_loader.cc`

- :ref:`file_lupnt.h`




Namespaces
----------


- :ref:`namespace_lupnt`


Classes
-------


- :ref:`exhale_class_classlupnt_1_1Sp3Loader`