mcdsky.sh
Last updated: May31,2018

Predict sky position and moon properties for the McDonald sky at a user-specified UT time and date for a given Ra,Dec on the sky.

 
 
% mcdsky.sh --help 

Usage: mcdsky.sh 01:32:58.198 +30:31:35.60 20180206 02:02:22  
arg1 - RA in sexigecimal format   
arg2 - DEC in sexigecimal format 
arg3 - UT date (YYYYMMDD)  
arg4 - UT Time (HH:MM:SS) 

% mcdsky.sh 01:32:58.198 +30:31:35.60 20180206 02:02:22 
======================================================================
Summary of SKYCAL data: 
Target RA,DEC                          : 01:32:58.20 +30:31:35.6
UT date                                : 20180206
UT                                     : 02:02:22
LST                                    : 04:10:57.31
Days since J2000.0                     :    6610.584961
Julian Date                            : 2458155.584977
Hour Angle                             : 02:37:59.11   (WEST)
Target Altitude,Azimuth (degrees)      :    56.183   280.129
Target airmass                         :   1.204
RA,DEC of Moon                         : 13:50:50.70 -05:58:57.0
Percentage moon illumination           : Moon down
Angle between target and moon (degrees): Moon down
Zenith distance of target (degrees)    :   33.8110
Zenith distance of moon (degrees)      : Moon down (V sky SB = 21.9 if dark) 

% ls
skycal.ascii  skycal.mfv
 

To test that the code is working, you can use this set of mcdsky.sh examples. Notice that a call to mcdsky.sh always produces an output to standard out. This same output is also always directed to a local file named "skycal.ascii". Another file is made named "skycal.mfv" This file is a more Machine-Frienfly-Version. Here is the version of skycal.mfv from the above example:
  
% cat skycal.mfv 
RSEX     01:32:58.20         / RA of target in sexigecimal format
DSEX     +30:31:35.6         / DEC of target in sexigecimal format
UTDATE   20180206            /  UT date in YYYYMMDD formatat
UTTIME   02:02:22            /  UT time in hh:mm:ss format
LST      04:10:57.31         / Local Sideral Time hh:mm:dd.dd    
DS2000      6610.584961      / Days since 2000.0 (float)       
MJD      2458155.584977      / Julian Date (float)              
HA       02:37:59.11         / target hour angle hh:mm:ss.ss     
ALT           56.182869      / target altitude (deg,float)     
AZ           280.128601      / target azimuth (deg,float)      
AIRMASS        1.203547      / target airmass (float)          
RMSEX    13:50:50.70         / RA of moon in sexigecimal format
DMSEX    -05:58:57.0         / DEC of moon in sexigecimal format
MILLUM          -99.000      / percentage moon illumination  
PHIMOON      -99.000000      / targ-moon ang.sep. (deg,float)
ZD            33.811020      / target zenith ang. (deg,float)
MZD          -99.000000      / moon zenith ang. (deg,float)  
VSKYSB        21.900000      / V sky SB mag/sq.arcsec (float)
 

To make retrieving information the file "skycal.mfv" a little easier I provide the simple script mcdskyget. You just give it the parameter name you want and whether or not to run in debug mode (usually "N"). Here is a brief example:

 
 
% mcdsky.sh 18:36:56.30 +38:47:01 20180530 09:21:38 >/dev/null 

% mcdskyget PHIMOON N
 65.962997

% mcdskyget RSEX N
 18:36:56.30

% mcdskyget BadName N
 none 

% mcdskyget namo Y
Debug flag is ON in mcdskyget 
Parameter name on input = namo 
Enter any key to continue:
Line 1:  RSEX     	/ RA of target in sexigecimal format  
Line 2:  DSEX     	/ DEC of target in sexigecimal format  
Line 3:  UTDATE     	/  UT date in YYYYMMDD formatat  
Line 4:  UTTIME     	/  UT time in hh:mm:ss format  
Line 5:  LST     	/ Local Sideral Time hh:mm:dd.dd  
Line 6:  DS2000     	/ Days since 2000.0 (float)  
Line 7:  MJD     	/ Julian Date (float)  
Line 8:  HA     	/ target hour angle hh:mm:ss.ss  
Line 9:  ALT     	/ target altitude (deg,float)  
Line 10:  AZ     	/ target azimuth (deg,float)  
Line 11:  AIRMASS     	/ target airmass (float)  
Line 12:  RMSEX     	/ RA of moon in sexigecimal format  
Line 13:  DMSEX     	/ DEC of moon in sexigecimal format  
Line 14:  MILLUM     	/ percentage moon illumination  
Line 15:  PHIMOON     	/ targ-moon ang.sep. (deg,float)  
Line 16:  ZD     	/ target zenith ang. (deg,float)  
Line 17:  MZD     	/ moon zenith ang. (deg,float)  
Line 18:  VSKYSB     	/ V sky SB mag/sq.arcsec (float)  
 none 


Notice that "mcdskyget" always gives an answer. If the parameter is unreognized, the the string "none" is produced. This little script is really intended for use in scripts that use information gathered by the call to mcdsky.sh.




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