rvcorrect
KBWestfall wrote on Jun 23, 2009
Hello,
I'm using rvcorrect both by giving the relevant numbers directly (year, month, day, ut, ra, dec) and by providing an image, which have the same values in its header. rvcorrect provides two different answers. Does anyone know what the problem might be? Is there a way to have rvcorrect output the information it uses to produce the heliocentric correction so that I can check that it is pulling the correct values from the header? If not, is there one way that is more trustworthy? My thinking is that I should use the numbers I enter directly into the program (because I then know what the program is using), but it's much more interactive (and, therefore, time intensive) than simply providing the image.
Please send along any advice you have.
Thanks,
Kyle
I'm using rvcorrect both by giving the relevant numbers directly (year, month, day, ut, ra, dec) and by providing an image, which have the same values in its header. rvcorrect provides two different answers. Does anyone know what the problem might be? Is there a way to have rvcorrect output the information it uses to produce the heliocentric correction so that I can check that it is pulling the correct values from the header? If not, is there one way that is more trustworthy? My thinking is that I should use the numbers I enter directly into the program (because I then know what the program is using), but it's much more interactive (and, therefore, time intensive) than simply providing the image.
Please send along any advice you have.
Thanks,
Kyle
Mike Fitzpatrick wrote on Jun 23, 2009
It would help to see the image header, it's possible for instance that the image is specifying an OBSERVAT keyword and the correction is being done differently than for the parameters. Another possibilit is that the DATE-OBS keyword is being used for the time of observation in the image but doesn't specify a time.
The 'header' and 'input' parameters can be used to echo the input values being used, otherwise how big are the differences we're talking about?
-Mike
The 'header' and 'input' parameters can be used to echo the input values being used, otherwise how big are the differences we're talking about?
-Mike
KBWestfall wrote on Jun 23, 2009
Thanks to your help I found the problem:
The header of the image gives the RA in degrees. The hours representation is in the comment for the RA keyword. As you can imagine, the difference was quite substantial, 9.17 versus -24.68.
Thanks for the help,
Kyle
# RVCORRECT: Observatory parameters for Calar Alto Observatory
# latitude = 37:13:25
# longitude = 2:32:46.5
# altitude = 2168
##YR MO DY UT RA DEC VOBS
## HJD VOBS VHELIO VLSR VDIURNAL VLUNAR VANNUAL VSOLAR
2007 1 16 6:08:37 267:43:45 29:23:53 0.0
2454116.75916 0.00 -24.68 -32.12 -0.167 -0.003 -24.515 -7.438
The header of the image gives the RA in degrees. The hours representation is in the comment for the RA keyword. As you can imagine, the difference was quite substantial, 9.17 versus -24.68.
Thanks for the help,
Kyle
Last post on Jun 23, 2009