;+
; NAME:
;	usno_maket
; PURPOSE:
;	Calculates the Chebyshev polynomials for the USNO asteroid ephemeris
; CATEGORY:
;	smei/gen/idl/ephem; USNO Asteroid Ephemeris; Chebyshev interpolation
; CALLING SEQUENCE:
	PRO usno_maket, time, t, tdot
; INPUTS:
;	time	scalar; type: double
;				Chebyshev time (-1<=time<1)
; OUTPUTS:
;	t		scalar; type: double
;				Chebyshev polynomial at 'time'
;	tdot	scalar; type: double
;				derivative of Chebyshev polynomial at 'time'
; INCLUDE:
	@compile_opt.pro		; On error, return to caller
; PROCEDURE:
;	Compute the values for the Chebyshev polynomial and their derivatives
;	to thirteenth order for a given time
; MODIFICATION HISTORY:
;	SEP-1999, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
;		Converted from USNO AE C-software
;-

t2p = dblarr(14, /nozero)
t2p[0] = 1.0d0
FOR i=1,13 DO t2p[i] = t2p[i-1]*time

t = [ 1.0 ,	$
	time ,	$
	2 * t2p[ 2] -     1,	$
	4 * t2p[ 3] -     3 * time,	$
	8 * t2p[ 4] -     8 * t2p[ 2] +     1,	$
   16 * t2p[ 5] -    20 * t2p[ 3] +     5 * time,	$
   32 * t2p[ 6] -    48 * t2p[ 4] +    18 * t2p[2] -    1,	$
   64 * t2p[ 7] -   112 * t2p[ 5] +    56 * t2p[3] -    7 * time,	$
  128 * t2p[ 8] -   256 * t2p[ 6] +   160 * t2p[4] -   32 * t2p[2] +    1,	$
  256 * t2p[ 9] -   576 * t2p[ 7] +   432 * t2p[5] -  120 * t2p[3] +    9 * time,	$
  512 * t2p[10] -  1280 * t2p[ 8] +  1120 * t2p[6] -  400 * t2p[4] +   50 * t2p[2] -   1,	$
 1024 * t2p[11] -  2816 * t2p[ 9] +  2816 * t2p[7] - 1232 * t2p[5] +  220 * t2p[3] -  11 * time,	$
 2048 * t2p[12] -  6144 * t2p[10] +  6912 * t2p[8] - 3584 * t2p[6] +  840 * t2p[4] -  72 * t2p[2] +  1,	$
 4096 * t2p[13] - 13312 * t2p[11] + 16640 * t2p[9] - 9984 * t2p[7] + 2912 * t2p[5] - 364 * t2p[3] + 13 * time ]

tdot = [ 0.0 ,	$
		 1.0 ,	$
     4 * time,	$
    12 * t2p[ 2] -      3,	$
    32 * t2p[ 3] -     16 * time,	$
    80 * t2p[ 4] -     60 * t2p[ 2] +      5,	$
   192 * t2p[ 5] -    192 * t2p[ 3] +     36 * time,	$
   448 * t2p[ 6] -    560 * t2p[ 4] +    168 * t2p[2] -     7,	$
  1024 * t2p[ 7] -   1536 * t2p[ 5] +    640 * t2p[3] -    64 * time,	$
  2304 * t2p[ 8] -   4032 * t2p[ 6] +   2160 * t2p[4] -   360 * t2p[2] +     9,	$
  5120 * t2p[ 9] -  10240 * t2p[ 7] +   6720 * t2p[5] -  1600 * t2p[3] +   100 * time,	$
 11264 * t2p[10] -  25344 * t2p[ 8] +  19712 * t2p[6] -  6160 * t2p[4] +   660 * t2p[2] -   11,	$
 24576 * t2p[11] -  61440 * t2p[ 9] +  55296 * t2p[7] - 21504 * t2p[5] +  3360 * t2p[3] -  144 * time,	$
 53248 * t2p[12] - 146432 * t2p[10] + 149760 * t2p[8] - 69888 * t2p[6] + 14560 * t2p[4] - 1092 * t2p[2] + 13]

RETURN  &  END