Universal to Conventional Elements
CALL sla_UE2EL (U, JFORMR,
JFORM, EPOCH, ORBINC, ANODE, PERIH,
AORQ, E, AORL, DM, JSTAT)
U  D(13)  universal orbital elements (updated; Note 1) 
 
(1) 
 combined mass ($M+m$) 
(2) 
 total energy of the orbit ($\alpha $) 
(3) 
 reference (osculating) epoch (${t}_{0}$) 
(46) 
 position at reference epoch (${r}_{0}$) 
(79) 
 velocity at reference epoch (${v}_{0}$) 
(10) 
 heliocentric distance at reference epoch 
(11) 
 ${r}_{0}.{v}_{0}$ 
(12) 
 date ($t$) 
(13) 
 universal eccentric anomaly ($\psi $) of date, approx 


JFORMR  I  requested element set (13; Note 3) 
JFORM  I  element set actually returned (13; Note 4) 
 
EPOCH  D  epoch of elements (${t}_{0}$ or $T$, TT MJD) 
 
ORBINC  D  inclination ($i$, radians) 
 
ANODE  D  longitude of the ascending node ($\Omega $, radians) 
 
PERIH  D  longitude or argument of perihelion ($\varpi $ or $\omega $, 
 

 radians) 
 
AORQ  D  mean distance or perihelion distance ($a$ or $q$, AU) 


E  D  eccentricity ($e$) 


AORL  D  mean anomaly or longitude ($M$ or $L$, radians, 



 JFORM=1,2 only) 


DM  D  daily motion ($n$, radians, JFORM=1 only) 


JSTAT  I  status: 



 0 = OK 



 $$1 = illegal PMASS 



 $$2 = illegal JFORMR 



 $$3 = position/velocity out of allowed range 
JFORM=1, suitable for the major planets:
EPOCH  =  epoch of elements ${t}_{0}$ (TT MJD)  
ORBINC  =  inclination $i$ (radians)  
ANODE  =  longitude of the ascending node $\Omega $ (radians)  
PERIH  =  longitude of perihelion $\varpi $ (radians)  
AORQ  =  mean distance $a$ (AU)  
E  =  eccentricity $e$$\left(0\le e<1\right)$  
AORL  =  mean longitude $L$ (radians)  
DM  =  daily motion $n$ (radians) 
JFORM=2, suitable for minor planets:
EPOCH  =  epoch of elements ${t}_{0}$ (TT MJD)  
ORBINC  =  inclination $i$ (radians)  
ANODE  =  longitude of the ascending node $\Omega $ (radians)  
PERIH  =  argument of perihelion $\omega $ (radians)  
AORQ  =  mean distance $a$ (AU)  
E  =  eccentricity $e$$\left(0\le e<1\right)$  
AORL  =  mean anomaly $M$ (radians) 
JFORM=3, suitable for comets:
EPOCH  =  epoch of perihelion $T$ (TT MJD)  
ORBINC  =  inclination $i$ (radians)  
ANODE  =  longitude of the ascending node $\Omega $ (radians)  
PERIH  =  argument of perihelion $\omega $ (radians)  
AORQ  =  perihelion distance $q$ (AU)  
E  =  eccentricity $e$$\left(0\le e\le 10\right)$ 
JFORMR  JFORM  meaning  
1  1  OK: elements are in the requested format  
1  2  never happens  
1  3  orbit not elliptical  
2  1  never happens  
2  2  OK: elements are in the requested format  
2  3  orbit not elliptical  
3  1  never happens  
3  2  never happens  
3  3  OK: elements are in the requested format 
JFORM  1  2  3  
EPOCH  ${t}_{0}$  ${t}_{0}$  $T$  
ORBINC  $i$  $i$  $i$  
ANODE  $\Omega $  $\Omega $  $\Omega $  
PERIH  $\varpi $  $\omega $  $\omega $  
AORQ  $a$  $a$  $q$  
E  $e$  $e$  $e$  
AORL  $L$  $M$    
DM  $n$     
where:
${t}_{0}$  is the epoch of the elements (MJD, TT)  
$T$  is the epoch of perihelion (MJD, TT)  
$i$  is the inclination (radians)  
$\Omega $  is the longitude of the ascending node (radians)  
$\varpi $  is the longitude of perihelion (radians)  
$\omega $  is the argument of perihelion (radians)  
$a$  is the mean distance (AU)  
$q$  is the perihelion distance (AU)  
$e$  is the eccentricity  
$L$  is the longitude (radians, $02\pi $)  
$M$  is the mean anomaly (radians, $02\pi $)  
$n$  is the daily motion (radians)  
  means no value is set 