[fitswcs] Question about sign convention for VELOSYS

[Phil Hodge]

On 06/17/2015 12:02 PM, William Thompson wrote:
> A question has arisen about the use of the WCS keywords SPECSYS and 
> VELOSYS for solar observations.  The plan is to set 
> SPECSYS='HELIOCEN', and to set VELOSYS to the radial velocity of the 
> observatory relative to the physical center of the Sun, with a 
> positive value if the movement is toward the Sun.  Is this the correct 
> sign convention? 

It seems to me that the velocity ought to be positive if the distance is 
increasing.

Phil