This component implements an NOAA POES HRPT receiver.  After installation,
the scripts described below will be install in the users PATH.

As the scripts are generated using GRC, GRC must be installed at runtime
in order for them to operate.


HRPT OPERATION

usrp_rx_hrpt.py
---------------

This GUI script will receive HRPT RF, demodulate, synchronize, and deframe
HRPT minor frames into a file.  The file stores a series of 11090 word,
16-bits per word corresponding to the HRPT minor frame format (only the
lower 10-bits per word are significant.)

The script file by default uses USRP side A, 1698 MHz, at decimation 16. A
configuration file 'usrp_rx_hrpt.cfg' in the current working directory will
allow changing this, as well as implementing persistent storage of GUI
entered parameters from invocation to invocation.

The present HRPT demodulator is only tested at decimation 16.  The only other
valid decimation rates are 24 and 32, which may word but with more bit
errors.  No other decimation rates will work.

usrp_rx_hrpt2.py
----------------

This GUI script uses fewer graphical displays to reduce CPU consumption on
slower machines, but otherwise operates identically to userp_rx_hrpt.py.

usrp_rx_hrpt_nogui.py
---------------------

This non-GUI script operates without a display and requires that all parameters
be set in the configuration file prior to running.  It has no command-line
parameters, and works identically to the GUI scripts.

demod_hrpt_file.py
------------------

This non-GUI script will operate on a file generated with
usrp_rx_cfile.py and output frames in the same format as above.  It does
*not* use the configuration file above; instead you must pass parameters to
it on the command line.  To exit the program, press Enter.

Usage: demod_hrpt_file.py: [options]

Options:
  -h, --help            show this help message and exit
  -d DECIM, --decim=DECIM
                        Set Decimation [default=16]
  -p PLL_ALPHA, --pll-alpha=PLL_ALPHA
                        Set pll_alpha [default=50m]
  -s SYNC_ALPHA, --sync-alpha=SYNC_ALPHA
                        Set sync_alpha [default=50m]
  -F FILENAME, --filename=FILENAME
                        Set Filename [default=usrp.dat]
  -o OUTPUT, --output=OUTPUT
                        Set Output [default=frames.dat]


LRIT Operation
--------------

The work-in-progress LRIT GRC script is not currently in a usable state.