The Huairou IDL package are coded to process the vector magnetic field data observed
by the Solar Magnetic Field Telescope at Huairou Solar Observing Station, Beijing 
Astronomical Observatory, Chinese Academy of Sciences. To use these programs, we assume
that you have installed the IDL Astronomy User's Library in your IDL searching path. 
If you have not done so, please download it at 
			http://idlastro.gsfc.nasa.gov/homepage.html
and install the library files to a directory of your IDL searching path.

This package can be used with IDL in Windows 95/98, Linux and Unix environment.

The package contains the following procedures:

HR_Calib    -- Calibrate the observed data
HR_ChgBtDir -- Manually change the direction of the transversal component of the
               vector magnetic field
HR_Current  -- Calculate current of the observed region
HR_Mag      -- Display the vector magnetogram for the calibrated and/or projection-
               corrected data, and/or save the result to a PostScript file
HR_Noise    -- calculate the 3-Sigma noise               
HR_Proj     -- Correct the projection effect for Huairou data
HR_Read     -- Read Huairou observation data
HR_sph2xy   -- Convert spherical coordinates to Cartesian coordinates for Huairou data
HR_xy2sph   -- Convert Cartesian coordinates to spherical coordinates for Huairou data
Cff1n       -- Compute the potential field from observed longitudinal component,
               called by HR_Calib
Sunparam    -- Calculate parameters of the Sun at a given time, called by HR_Proj
Readme.txt  -- This file
Huairou_IDL.html -- Online description of each procedure in this package

Any comment and suggestion about development and use of this package are highly 
appreciated and can direct to: lihui@mail.pmo.ac.cn

Good luck.

August 22, 2001
Hui LI
@Beijing
