;+
; PROJECT:
;	HESSI
; NAME: 
;	HSI_GRID_PARAMETERS	
;
; PURPOSE:
;	This function returns a structure with the grid characteristics.
;
; CATEGORY:
;
;
; CALLING SEQUENCE:
;	grid_parameter_structure = hsi_grid_parameters()
;
; CALLS:
;	Uses grid_parameter structure defined within HSI_STRUCT_DEF.
;
; INPUTS:
;       none explicit, only through commons;
;
; OPTIONAL INPUTS:
;	none
;
; OUTPUTS:
;       none explicit, only through commons;
;
; OPTIONAL OUTPUTS:
;	none
;
; KEYWORDS:
;	none
; COMMON BLOCKS:
;	none
;
; SIDE EFFECTS:
;	none
;
; RESTRICTIONS:
;	none
;
; PROCEDURE:
;	none
;
; MODIFICATION HISTORY:
;	Version 1, richard.schwartz@gsfc.nasa.gov, 24-nov-1998. Skeletal.
;
;-
function hsi_grid_parameters

grid_parameters = {grid_parameters, $
	pitch:  [4.38,7.59,13.15,22.78,39.45,68.33,118.34,204.98,355.03], $ ; Angular pitch
	orient: [135,45,0,90,0,90,0,135,45.]*!dtor, $		; likely to change
	coll_phase: 0.5*!pi*[0,0,0,0,0,0,0,0,0], $    	; relative collimator phases        
	slit2slat: [.020/.014,.035/.024,.061/.041,.106/.071, $
	.184/.122,.318/.212,.477/.441,.811/.779,1.487/1.267], $ ; GH Jan 7, 1998
	spin_period: 4.0, $					; will not be needed after RAS emulation
	thickness: [0.075,0.120,3.6,6.2,10.7,18.6,6.2,6.2,30.0],$ ; Jan 9, 1998
	delta: !pi*[0.970,0.632,0.332,0.054,0.938,0.471,0.866,0.904,0.540] }   ; random collimator phases 



return, grid_parameters

end