.. _tutorials/sinex:

Sinex Files
============

Geodepy has the ability to read and write sinex files. Below we will explore how to 
read certain parts of a sinex file and ultimately how to write a new sinex file. In 
this tutorial the sinex file "STR1AUSPOS.SNX" found in the docs folder will be used. This was 
generated using AUSPOS.

Reading Sinex Files
-------------------

Sinex files are split into different blocks all containing different types of information. 
These blocks are deliniated by a starting line that uses a "+BLOCKNAME" and an ending line 
using a "-BLOCKNAME". The blocks found in a sinex file can be printed using the read_sinex_blocks 
function as seen below.

.. code:: python

    import geodepy.gnss

    geodepy.gnss.read_sinex_blocks("GeodePy/docs/tutorials/STR1AUSPOS.SNX")

    >>FILE/REFERENCE
    >>INPUT/ACKNOWLEDGMENTS
    >>SOLUTION/STATISTICS
    >>...

Particular blocks can be read using other GeodePy functions. Below the acknowledgments 
block will be read.

.. code:: python

    print(geodepy.gnss.read_sinex_input_acknowledgments_block("GeodePy/docs/tutorials/STR1AUSPOS.SNX"))

    >>['+INPUT/ACKNOWLEDGMENTS', 
       '*AGY DESCRIPTION________________________________________________________________', 
       ' XYZ My agency/institute and its address', 
       ' IGS International GNSS Service', 
       '-INPUT/ACKNOWLEDGMENTS']

All blocks that can be read by GeodePy can be found in the :ref:`sinex features <features/gnss>` 
page. If a certain block is needed that can't be found here, any lines can be read using 
the read_sinex_custom function as seen below.

.. code:: python

    print(geodepy.gnss.read_sinex_custom(
        "GeodePy/docs/tutorials/STR1AUSPOS.SNX", #file name
        5, #start line
        6 #end line
    ))

    >>['DESCRIPTION        My agency/institute', 
       'OUTPUT             One-session solution generated by RNX2SNX BPE']

Writing Sinex Files
-------------------

GeodePy can also be used to write new sinex files. This is done using the writeSINEX 
function. This function uses many of the read sinex functions to create blocks. Below 
we will explore the process of taking a sinex file and writing a new sinex file with 
only a select few blocks.

.. code:: python

    import geodepy.gnss

    #The blocks in new file will be header, site ID and solution epochs

    headerSTR1 = geodepy.gnss.read_sinex_header_block("GeodePy/docs/tutorials/STR1AUSPOS.SNX")
    siteIDSTR1 = geodepy.gnss.read_sinex_site_id_block("GeodePy/docs/tutorials/STR1AUSPOS.SNX")
    epochSTR1 = geodepy.gnss.read_sinex_solution_epochs_block("GeodePy/docs/tutorials/STR1AUSPOS.SNX")

    geodepy.gnss.writeSINEX(
        "GeodePy/docs/tutorials/STR1AUSPOS_new.SNX", #new file path
        header=headerSTR1, #header str
        siteID=siteIDSTR1, #siteID str
        solutionEpochs=epochSTR1 #solution Epochs str
    )

This file can also be found in the docs folder.