Catalogs

The Source Catalog system in AstrID provides a convenient way for the user to specify a list of sourcesto be observed, as well as a way to refer to standard catalogs of objects. At a minimum for each source there must be a name and a location (RA/Dec or Glat/Glon, etc). Other parameters may be set, such as radial velocity. An example of a simple Catalog is:

# My source list
format=spherical
coordmode=J2000
HEAD = NAME   RA        DEC
Object1  09:56:16.98  +49:16:25.5
Object2  10:56:16.98  +50:16:25.5
Object3  11:56:16.98  +51:16:25.5
Object4  12:56:16.98  +52:16:25.5

There are three formats of catalogs:

1. SPHERICAL: a fixed position in one of our standard coordinate systems, e.g. RA/Dec, Az/El, Glon/Glat, etc.

2. EPHEMERIS: a table of positions for moving sources (comets, asteroids, satellites, etc)

3. NNTLE NASA/NORAD: Two-line element sets for Earth satellites.

In addition, the following solar system bodies may be referred to by name, i.e. no catalog needs to be invoked for the system to understand these names: 'Sun', 'Moon', 'Mercury', 'Venus', 'Mars', 'Jupiter', 'Saturn', 'Uranus', 'Neptune', and 'Pluto'. These names are case-insensitive and may be given to any Scan Type function.

To use the catalog system, you invoke the Catalog() command within SBs and pass names of the desired objects to any of the scan functions. All sources named in all the catalogs that have been invoked are available within an SB. If the same name appears in two or more catalogs, the name from the most recently invoked catalog will prevail. Name comparisons are case-insensitive, hence “b2322+16” “B2322+16” are equivalent.

Getting a Catalog into AstrID

Although one can include any number of Catalogs in an SB, the standard practice is to put all the Catalogs into separate files that are then brought into the SB via multiple calls to the Catalog() command. This:

1. keeps SBs simple and without clutter

2. allows changes to be made to a Catalog without having to validate and re-save the SB

The best way to learn about how to bring Catalogs into an SB is through an example. Let’s suppose that there are two Catalogs that you need for your observations. These two catalogs are in the following files:

• /home/astro-util/projects/GBTog/cats/sources.cat

• /home/astro-util/projects/GBTog/cats/pointing.cat

These catalogs may be loaded into the SB as shown in the following example:

#first load the catalog with the flux calibrators
cata=Catalog('/home/astro-util/projects/GBTog/cats/sources.cat')

#now load the catalog with the pointing source list
catb=Catalog('/home/astro-util/projects/GBTog/cats/pointing.cat')

#Objects defined in loaded catalogs may now be used in scan functions
#Object1 is in source.cat and 0006-0004 is in pointing.cat
Track('Object1',None, 60)
Slew('0006-0004')

All sources from all catalogs are available and referenced by name within the scope of the SB, with the exception that for duplicate source names only the last entry of that name will be recognized. After loading a Catalog any scan function may be run by giving it the source name as shown above.

Catalog Format

A Catalog typically has two sections: a header section followed by a table of information for all the sources. The header section consists of KEYWORD = VALUE pairs. The KEYWORD = VALUE pairs tell the SB interpreter how to read the information in the table section of the Catalog. Once a keyword value is given, its value will persist until re-set or the end of the Catalog is reached. The keywords are case-insensitive. The values for a keyword must not contain any embedded blanks (except source names in NNTLE format).

A Catalog can contain comments with the beginning of a comment being denoted by the hash symbol, #. All information on a line after the hash symbol is considered to be part of the comment. After the header, each source in the Catalog occupies a single line. You should not use the hash symbol in source names.

Catalog Header Keywords

Catalog Header Keywords are used to define how the catalog entries should be read. The keywords and their values are case insensitive. The example shown below will be used to describe some of the Catalog Header Keywords:

# My source list
format=spherical
HEAD = NAME COORDMODE   RA  DEC        RESTFREQ   VELDEF     VEL  type
Object1  J2000  09:56:16.9  +49:16:25  1420.405  VRAD-LSR   -25.3  HII
Src_A    J2000  10:56:16.9  +50:16:25  1665.401  VOPT-BAR   100.9  Gal

Unless mentioned otherwise, the following keywords should be listed as column headings under HEAD:

HEAD

This gives the header for tabular data, and consists of a list of any keywords. This should appear as the last line in the header before lines giving information about the sources in the catalog. The default header is HEAD = NAME RA DEC VELOCITY. In the above example we have added more entries than the default. We have also created a new keyword named type.

NAME

The source name is any string up to 32 characters long. The name should not contain any embedded blanks or hashes.

COORDMODE

The default is J2000. Possible values are:

• J2000

• B1950

• JMEAN (mean coordinate of date given by EQUINOX)

• GAPPT (geocentric apparent coordinates of date)

• GALACTIC

• HADEC

• AZEL

• ENCODER

In the above example we put the COORDMODE keyword in the HEAD line since we have sources whose positions are given in different coordinate modes (J2000 and B1950). This keyword may be given as either a header keyword or columnn heading under HEAD.

VEL or VELOCITY

The radial velocity in km/sec. The Default is to use any previous setting or 0.0 if there is none.

VELDEF

Velocity definition in the FITS convention, e.g. VOPT-BAR, VRAD-LSR, etc. (see https://safe.nrao.edu/wiki/bin/view/GB/Data/VelDefFits).

Todo

Move the content of the wiki page to the Explanation section in GBTdocs.

The default is the velocity definition or reference frame that was previously set. In the a bove example we put the VELDEF keyword in the HEAD line since we have sources whose velocity definitions are different. This keyword may be given as either a header keyword or columnn heading under HEAD. This value will also override the velocity definition in the configuration.

RESTFREQ

The rest frequency, in MHz. The default is to use the previous setting. Again we put the RESTFREQ keyword in the HEAD line since we are defining two different spectral line rest frequencies for each source. Note that this is an “expert” keyword as one has to be aware of any conflicts with the hardware configuration. This keyword may be given as either a header keyword or columnn heading under HEAD.

RA, HA, DEC, AZ, EL, GLON, GLAT

A pair of coordinates must be given: RA/DEC, HA/DEC, AZ/EL, or GLON/GLAT. Angle formats may be either in sexagesimal with colons (e.g. dd:mm:ss.ss) or in decimal format. RA and HA are always in hours regardless of decimal or sexagesimal notation, while all other coordinates use degrees of arc in both formats.

EQUINOX

Used if the Coordmode is JMEAN. The value is a float (e.g. 2006 December 1, 12:00 UT would be 2006.919178082192). This keyword may be given as either a header keyword or columnn heading under HEAD.

# My source list
format=spherical
coordmode=jmean
equinox=2007.123456
HEAD = NAME     RA        DEC   
Object2  10:56:16.98  +50:16:25.5

DATE

For use in the EPHEMERIS format only. The UTC date, either 2005-06-23 or 2005-Jun-23 form. This keyword may be given as either a header keyword or columnn heading under HEAD.

UTC

For use in the EPHEMERIS format only. The UTC time in the form hh:mm:ss.

DRA, DHA, DDEC, DAZ, DEL, DLON, DLAT

For use in the EPHEMERIS format only. The coordinate rate keywords given in arcsec per hour.

DVEL

For use in the EPHEMERIS format only. The radial velocity rate in km/s/hour.

FILE

For use in NNTLE format only. This keyword value may refer to a file or a URL containing a 2-line element set. This keyword may not be listed as a column name under HEAD.

USERADVEL

For use in the NNTLE format only. If this is set to 1, then the radial velocity tracking will be performed. Otherwise, if this is set to 0 or is missing then radial velocity tracking will not be performed. This keyword may not be listed as a column name under HEAD.

Ephemeris Catalogs

A Catalog can also be used as an Ephemeris for the position of a moving object, such as a comet or asteroid. To make the Catalog into an Ephemeris the first non-comment line of the Catalog must contain FORMAT = EPHEMERIS.

The header of the Catalog for an Ephemeris can also contain the NAME, COORDMODE, VELDEF and HEAD keywords. The “data lines” in the Catalog must contain at least the date, the time, and a pair of coordinates for an Ephemeris. Optional parameters are coordinate rates, radial velocity and radial velocity rate. User-defined parameters may also be added.

The dates and times are required to be in UTC. The dates and times can be specified in any legal python form, for example:

1. YYYY-MM-DD hh:mm:ss where MM is month number (e.g August = 09)

2. YYYY-MMM-DD hh:mm:ss where MMM is the abbreviated month name such as Jan, Feb, etc.

The ephemeris table should contain enough entries to cover a period longer than that required by a particular observing session with sufficient time resolution for the expected motion with respect to the telescope’s beam size. The observing system selects the portion of the table needed for the current scan start time and duration.

Instructions for getting ephemeris from JPL

Tracking a comet which does not track at the sidereal rate will require the use of an external file generated from the NASA JPL Horizons website which holds a database of all the orbital parameters of all major and minor bodies in the solar system. First you must download the ephemeris file for your object of interest from the website: https://ssd.jpl.nasa.gov/horizons/app.html. Then you will have to convert the file into the CATALOG format for AstrID.

When you go to https://ssd.jpl.nasa.gov/horizons/app.html you should see something like this:

Your entries should be:

• Ephemeris Type: Observer Table

• Target Body: SELECT YOUR OBJECT.

  Clicking on the blue Edit button will open a form to search for the object of interest.

• Observer Location: Green Bank (GBT) [-9] (radar) (\(280^{\circ}\,09^{\prime}\, 36.7^{\prime\prime}\) E \(38^{\circ} 25^{\prime} 59.1^{\prime\prime}\) N, 873.10m).

  To set the location to Green Bank, first click Edit, then type `9 in the search bar and press Search; the correct location should now appear.

• Time Specification: CHOOSE YOUR RANGE.

  The ephemeris table should contain enough entries to cover a period longer than that required by a particular observing session. The observing system selects the portion of the table needed for the current scan start time and duration. If the position of the comet is changing rapidly, you should select a “step” range of 5 mins or shorter. If the comet is further out in the solar system and is not moving as rapidly with respect to the sidereal rate, a “step” range of 10-15 mins may be adequate to track” the comet. Consult your GBT project friend if you are unsure of the step range you should choose.

• Table Settings: QUANTITIES=1,3,20.

  Fig. 24 shows the quantities that should be selected through the web interface to properly generate an ephemeris for tracking a comet.

  Note

  The dates and times are required to be in UTC. The dates and times can be specified in any legal python form, for example:

  1. YYYY-MM-DD hh:mm:ss where MM is month number (e.g August = 09)

  2. YYYY-MMM-DD hh:mm:ss where MMM is the abbreviated month name such as Jan, Feb, etc.

Fig. 24 Selecting quantities to generate an ephemeris.

After clicking Generate Ephemeris, you should save the file to a directory in your area in Green Bank. The ephemeris file will begin with a large amount of header information followed by lines containing the date, time and pairs of coordinates as shown here:

*******************************************************************************
JPL/HORIZONS                   103P/Hartley 2              2016-Apr-05 07:53:21
Rec #:900870 (+COV)   Soln.date: 2014-Nov-10_13:49:39   # obs: 6506 (1986-2013)
 
FK5/J2000.0 helio. ecliptic osc. elements (au, days, deg., period=Julian yrs): 
 
  EPOCH=  2456981.5 ! 2014-Nov-20.0000000 (TDB)    RMSW= n.a.                  
   EC= .6937804720128784   QR= 1.064195154203179   TP= 2457863.8230300969      
   OM= 219.7487450736021   W= 181.3222857728302    IN= 13.6042724340803        
   A= 3.475268743304754    MA= 225.7701522441      ADIST= 5.886342332406328    
   PER= 6.4787437937458    N= .152132314           ANGMOM= .023095142          
   DAN= 5.88279            DDN= 1.06431            L= 41.0339546               
   B= -.310996             MOID= .0720049          TP= 2017-Apr-20.3230300969  
 
Comet physical (GM= km^3/s^2; RAD= km):                                        
   GM= n.a.                RAD= .800                                           
   M1=  14.7     M2=  n.a.     k1=  8.     k2= n.a.     PHCOF= n.a.            
 
COMET comments 
1: soln ref.= JPL#252, data arc: 1986-03-15 to 2013-05-14
2: k1=8.;
*******************************************************************************
 
 
*******************************************************************************
Ephemeris / WWW_USER Tue Apr  5 07:53:22 2016 Pasadena, USA      / Horizons    
*******************************************************************************
Target body name: 103P/Hartley 2                  {source: JPL#252}
Center body name: Earth (399)                     {source: DE431}
Center-site name: Green Bank (GBT)
*******************************************************************************
Start time      : A.D. 2016-Apr-05 00:00:00.0000 UT      
Stop  time      : A.D. 2016-Apr-06 00:00:00.0000 UT      
Step-size       : 5 minutes
*******************************************************************************
Target pole/equ : No model available
Target radii    : 0.8 km                                                       
Center geodetic : 280.160200,38.4330940,0.8760930 {E-lon(deg),Lat(deg),Alt(km)}
Center cylindric: 280.160200,5003.37558,3943.7589 {E-lon(deg),Dxy(km),Dz(km)}
Center pole/equ : High-precision EOP model        {East-longitude +}
Center radii    : 6378.1 x 6378.1 x 6356.8 km     {Equator, meridian, pole}    
Target primary  : Sun
Vis. interferer : MOON (R_eq= 1737.400) km        {source: DE431}
Rel. light bend : Sun, EARTH                      {source: DE431}
Rel. lght bnd GM: 1.3271E+11, 3.9860E+05 km^3/s^2                              
Small-body perts: Yes                             {source: SB431-BIG16}
Atmos refraction: NO (AIRLESS)
RA format       : HMS
Time format     : CAL 
RTS-only print  : NO       
EOP file        : eop.160404.p160626                                           
EOP coverage    : DATA-BASED 1962-JAN-20 TO 2016-APR-04. PREDICTS-> 2016-JUN-25
Units conversion: 1 au= 149597870.700 km, c= 299792.458 km/s, 1 day= 86400.0 s 
Table cut-offs 1: Elevation (-90.0deg=NO ),Airmass (>38.000=NO), Daylight (NO )
Table cut-offs 2: Solar Elongation (  0.0,180.0=NO ),Local Hour Angle( 0.0=NO )
*******************************************************************************
Initial FK5/J2000.0 heliocentric ecliptic osculating elements (au, days, deg.):
  EPOCH=  2456981.5 ! 2014-Nov-20.0000000 (TDB)    RMSW= n.a.                  
   EC= .6937804720128784   QR= 1.064195154203179   TP= 2457863.8230300969      
   OM= 219.7487450736021   W= 181.3222857728302    IN= 13.6042724340803        
Comet physical (GM= km^3/s^2; RAD= km):                                        
   GM= n.a.                RAD= .800                                           
   M1=  14.7     M2=  n.a.     k1=  8.     k2= n.a.     PHCOF= n.a.            
**********************************************************************************************
 Date__(UT)__HR:MN     R.A._(ICRF/J2000.0)_DEC dRA*cosD d(DEC)/dt            delta      deldot
**********************************************************************************************
$$SOE
 2016-Apr-05 00:00 C   18 27 00.30 -13 25 32.9 12.40954  9.786338 3.50004632213965 -36.1740593
 2016-Apr-05 00:05 C   18 27 00.37 -13 25 32.0 12.40419  9.784071 3.49997377062988 -36.1812496
                                     ...........
                                       .......
                                         ...

Now that you have your ephemeris, it needs to be converted to a form that AstrID can read. You can do this by running the Python script jpl2astrid from any directory in your area on the Green Bank computer system. If you just type jpl2astrid, and give it no arguments, it lists instructions, like this:

Usage:  jpl2astrid cometfilename.txt [vel]
    If 'vel' is blank,  do not write the radial velocities.
    If 'vel' is non-blank,  do write the radial velocities.
    output will have '.astrid' extension.
    Include in Astrid with, e.g. Catalog(fullpath/cometfile.astrid ) 
 
    If '-h' or '-help' instead of 1st argument, print help message
 
 Access the JPL Horizons web interface: http://ssd.jpl.nasa.gov/horizons.cgi
 Set up Horizons web-interface as follows
   ephemeris type:   OBSERVER
   target body:      [select the object]
   Observer Location:   Green Bank (GBT) [select from list of observatories]
   Time Span:        [put in desired values]
   Table Settings:   QUANTITIES=1,3,20
        i.e., (1)Astrometric RA&Dec, (3)rates RA&Dec, and (20)Range and range rate
   Display/Output:   plain text
 
 Use the web browser file menu to save the output file as (for example) cometfilename.txt

If you give it a file name, say by typing jpl2astrid jplephemfile.txt, it produces another file in the form for AstrID Catalogs. You should verify that the first non-comment line of the resulting catalog file contains FORMAT = EPHEMERIS.

You now have a valid catalog file that AstrID will be able to use. When you load the catalog into AstrID, make sure you have the correct path and that the name of the comet is exactly what is in the .astrid catalog file in “quotations”. The catalog file should look something like this:

FORMAT = EPHEMERIS
VELDEF = VRAD-TOP
COORDMODE = J2000
HEAD = date utc ra dec dra ddec
# 1: soln ref.= JPL#252 
NAME = 103P/Hartley 
2016-Apr-05 00:00 18:27:00.30 -13:25:32.9 12.7582 9.7863 
2016-Apr-05 00:05 18:27:00.37 -13:25:32.0 12.7527 9.7841 
2016-Apr-05 00:10 18:27:00.44 -13:25:31.2 12.7469 9.7818 
2016-Apr-05 00:15 18:27:00.52 -13:25:30.4 12.7409 9.7796 
2016-Apr-05 00:20 18:27:00.59 -13:25:29.6 12.7347 9.7774 
2016-Apr-05 00:25 18:27:00.66 -13:25:28.8 12.7282 9.7752 
2016-Apr-05 00:30 18:27:00.73 -13:25:28.0 12.7215 9.7730 
2016-Apr-05 00:35 18:27:00.80 -13:25:27.2 12.7145 9.7709 
2016-Apr-05 00:40 18:27:00.87 -13:25:26.4 12.7074 9.7688 
2016-Apr-05 00:45 18:27:00.94 -13:25:25.5 12.7000 9.7667 
2016-Apr-05 00:50 18:27:01.01 -13:25:24.7 12.6923 9.7646 
2016-Apr-05 00:55 18:27:01.08 -13:25:23.9 12.6845 9.7626 
2016-Apr-05 01:00 18:27:01.15 -13:25:23.1 12.6764 9.7606 
2016-Apr-05 01:05 18:27:01.22 -13:25:22.3 12.6681 9.7586 
2016-Apr-05 01:10 18:27:01.29 -13:25:21.5 12.6596 9.7566 
2016-Apr-05 01:15 18:27:01.36 -13:25:20.7 12.6509 9.7547 
2016-Apr-05 01:20 18:27:01.43 -13:25:19.9 12.6420 9.7529 
2016-Apr-05 01:25 18:27:01.50 -13:25:19.0 12.6329 9.7510 
2016-Apr-05 01:30 18:27:01.57 -13:25:18.2 12.6236 9.7492 
2016-Apr-05 01:35 18:27:01.64 -13:25:17.4 12.6141 9.7474 
2016-Apr-05 01:40 18:27:01.71 -13:25:16.6 12.6043 9.7457 
2016-Apr-05 01:45 18:27:01.78 -13:25:15.8 12.5944 9.7440 
2016-Apr-05 01:50 18:27:01.85 -13:25:15.0 12.5844 9.7423 
2016-Apr-05 01:55 18:27:01.92 -13:25:14.2 12.5741 9.7407 
2016-Apr-05 02:00 18:27:01.99 -13:25:13.4 12.5636 9.7391 
2016-Apr-05 02:05 18:27:02.06 -13:25:12.6 12.5530 9.7376 
2016-Apr-05 02:10 18:27:02.13 -13:25:11.8 12.5422 9.7361 
2016-Apr-05 02:15 18:27:02.20 -13:25:10.9 12.5313 9.7347 
2016-Apr-05 02:20 18:27:02.27 -13:25:10.1 12.5202 9.7333 
2016-Apr-05 02:25 18:27:02.34 -13:25:09.3 12.5089 9.7319 
2016-Apr-05 02:30 18:27:02.41 -13:25:08.5 12.4975 9.7306 
2016-Apr-05 02:35 18:27:02.48 -13:25:07.7 12.4859 9.7293 
2016-Apr-05 02:40 18:27:02.55 -13:25:06.9 12.4742 9.7281 
2016-Apr-05 02:45 18:27:02.62 -13:25:06.1 12.4623 9.7269 
2016-Apr-05 02:50 18:27:02.69 -13:25:05.3 12.4503 9.7258 
2016-Apr-05 02:55 18:27:02.76 -13:25:04.5 12.4382 9.7247 
2016-Apr-05 03:00 18:27:02.83 -13:25:03.7 12.4259 9.7237 
2016-Apr-05 03:05 18:27:02.90 -13:25:02.9 12.4136 9.7227 
2016-Apr-05 03:10 18:27:02.97 -13:25:02.0 12.4011 9.7218 
2016-Apr-05 03:15 18:27:03.04 -13:25:01.2 12.3885 9.7209 
2016-Apr-05 03:20 18:27:03.10 -13:25:00.4 12.3758 9.7201 
2016-Apr-05 03:25 18:27:03.17 -13:24:59.6 12.3630 9.7194 
2016-Apr-05 03:30 18:27:03.24 -13:24:58.8 12.3501 9.7187 
2016-Apr-05 03:35 18:27:03.31 -13:24:58.0 12.3371 9.7180 
2016-Apr-05 03:40 18:27:03.38 -13:24:57.2 12.3240 9.7174 
2016-Apr-05 03:45 18:27:03.45 -13:24:56.4 12.3109 9.7168 
2016-Apr-05 03:50 18:27:03.52 -13:24:55.6 12.2977 9.7164 
2016-Apr-05 03:55 18:27:03.58 -13:24:54.8 12.2844 9.7159 
2016-Apr-05 04:00 18:27:03.65 -13:24:54.0 12.2710 9.7155 
2016-Apr-05 04:05 18:27:03.72 -13:24:53.2 12.2576 9.7152 
2016-Apr-05 04:10 18:27:03.79 -13:24:52.3 12.2441 9.7149 
2016-Apr-05 04:15 18:27:03.86 -13:24:51.5 12.2306 9.7147 
2016-Apr-05 04:20 18:27:03.93 -13:24:50.7 12.2171 9.7146 
2016-Apr-05 04:25 18:27:03.99 -13:24:49.9 12.2035 9.7145 
2016-Apr-05 04:30 18:27:04.06 -13:24:49.1 12.1899 9.7144 
2016-Apr-05 04:35 18:27:04.13 -13:24:48.3 12.1762 9.7144 
2016-Apr-05 04:40 18:27:04.20 -13:24:47.5 12.1625 9.7145 
2016-Apr-05 04:45 18:27:04.26 -13:24:46.7 12.1489 9.7146 
2016-Apr-05 04:50 18:27:04.33 -13:24:45.9 12.1352 9.7148 
2016-Apr-05 04:55 18:27:04.40 -13:24:45.1 12.1215 9.7151 
2016-Apr-05 05:00 18:27:04.47 -13:24:44.3 12.1078 9.7154 
2016-Apr-05 05:05 18:27:04.53 -13:24:43.5 12.0941 9.7157 
2016-Apr-05 05:10 18:27:04.60 -13:24:42.6 12.0805 9.7161 
2016-Apr-05 05:15 18:27:04.67 -13:24:41.8 12.0668 9.7166 
2016-Apr-05 05:20 18:27:04.74 -13:24:41.0 12.0532 9.7171 
2016-Apr-05 05:25 18:27:04.80 -13:24:40.2 12.0396 9.7177 
2016-Apr-05 05:30 18:27:04.87 -13:24:39.4 12.0261 9.7184 
2016-Apr-05 05:35 18:27:04.94 -13:24:38.6 12.0126 9.7191 
2016-Apr-05 05:40 18:27:05.00 -13:24:37.8 11.9991 9.7198 
2016-Apr-05 05:45 18:27:05.07 -13:24:37.0 11.9857 9.7206 
2016-Apr-05 05:50 18:27:05.14 -13:24:36.2 11.9723 9.7215 
2016-Apr-05 05:55 18:27:05.20 -13:24:35.4 11.9590 9.7224 
2016-Apr-05 06:00 18:27:05.27 -13:24:34.6 11.9458 9.7234 
2016-Apr-05 06:05 18:27:05.34 -13:24:33.8 11.9327 9.7244 
2016-Apr-05 06:10 18:27:05.40 -13:24:32.9 11.9196 9.7255 
2016-Apr-05 06:15 18:27:05.47 -13:24:32.1 11.9066 9.7267 
2016-Apr-05 06:20 18:27:05.54 -13:24:31.3 11.8937 9.7279 
2016-Apr-05 06:25 18:27:05.60 -13:24:30.5 11.8809 9.7291 
2016-Apr-05 06:30 18:27:05.67 -13:24:29.7 11.8682 9.7304 
2016-Apr-05 06:35 18:27:05.73 -13:24:28.9 11.8557 9.7318 
2016-Apr-05 06:40 18:27:05.80 -13:24:28.1 11.8432 9.7332 
2016-Apr-05 06:45 18:27:05.87 -13:24:27.3 11.8308 9.7346 
2016-Apr-05 06:50 18:27:05.93 -13:24:26.5 11.8186 9.7361 
2016-Apr-05 06:55 18:27:06.00 -13:24:25.7 11.8065 9.7377 
2016-Apr-05 07:00 18:27:06.06 -13:24:24.9 11.7945 9.7393 
2016-Apr-05 07:05 18:27:06.13 -13:24:24.0 11.7826 9.7410 
2016-Apr-05 07:10 18:27:06.19 -13:24:23.2 11.7709 9.7427 
2016-Apr-05 07:15 18:27:06.26 -13:24:22.4 11.7593 9.7444 
2016-Apr-05 07:20 18:27:06.32 -13:24:21.6 11.7479 9.7462 
2016-Apr-05 07:25 18:27:06.39 -13:24:20.8 11.7367 9.7481 
2016-Apr-05 07:30 18:27:06.45 -13:24:20.0 11.7256 9.7499 
2016-Apr-05 07:35 18:27:06.52 -13:24:19.2 11.7146 9.7519 
2016-Apr-05 07:40 18:27:06.59 -13:24:18.4 11.7038 9.7538 
2016-Apr-05 07:45 18:27:06.65 -13:24:17.6 11.6932 9.7559 
2016-Apr-05 07:50 18:27:06.72 -13:24:16.7 11.6828 9.7579 
2016-Apr-05 07:55 18:27:06.78 -13:24:15.9 11.6725 9.7600 
2016-Apr-05 08:00 18:27:06.85 -13:24:15.1 11.6625 9.7622 
2016-Apr-05 08:05 18:27:06.91 -13:24:14.3 11.6526 9.7643 
2016-Apr-05 08:10 18:27:06.97 -13:24:13.5 11.6429 9.7666 
2016-Apr-05 08:15 18:27:07.04 -13:24:12.7 11.6334 9.7688 
2016-Apr-05 08:20 18:27:07.10 -13:24:11.9 11.6241 9.7711 
2016-Apr-05 08:25 18:27:07.17 -13:24:11.1 11.6150 9.7734 
2016-Apr-05 08:30 18:27:07.23 -13:24:10.2 11.6061 9.7758 
2016-Apr-05 08:35 18:27:07.30 -13:24:09.4 11.5974 9.7782 
2016-Apr-05 08:40 18:27:07.36 -13:24:08.6 11.5889 9.7806 
2016-Apr-05 08:45 18:27:07.43 -13:24:07.8 11.5806 9.7831 
2016-Apr-05 08:50 18:27:07.49 -13:24:07.0 11.5726 9.7856 
2016-Apr-05 08:55 18:27:07.56 -13:24:06.2 11.5647 9.7881 
2016-Apr-05 09:00 18:27:07.62 -13:24:05.4 11.5571 9.7906 
2016-Apr-05 09:05 18:27:07.68 -13:24:04.5 11.5497 9.7932 
2016-Apr-05 09:10 18:27:07.75 -13:24:03.7 11.5426 9.7958 
2016-Apr-05 09:15 18:27:07.81 -13:24:02.9 11.5357 9.7984 
2016-Apr-05 09:20 18:27:07.88 -13:24:02.1 11.5290 9.8010 
2016-Apr-05 09:25 18:27:07.94 -13:24:01.3 11.5225 9.8037 
2016-Apr-05 09:30 18:27:08.01 -13:24:00.5 11.5163 9.8064 
2016-Apr-05 09:35 18:27:08.07 -13:23:59.7 11.5103 9.8091 
2016-Apr-05 09:40 18:27:08.13 -13:23:58.8 11.5046 9.8118 
2016-Apr-05 09:45 18:27:08.20 -13:23:58.0 11.4991 9.8146 
2016-Apr-05 09:50 18:27:08.26 -13:23:57.2 11.4938 9.8173 
2016-Apr-05 09:55 18:27:08.33 -13:23:56.4 11.4888 9.8201 
2016-Apr-05 10:00 18:27:08.39 -13:23:55.6 11.4840 9.8229 
2016-Apr-05 10:05 18:27:08.45 -13:23:54.8 11.4795 9.8257 
2016-Apr-05 10:10 18:27:08.52 -13:23:53.9 11.4753 9.8285 
2016-Apr-05 10:15 18:27:08.58 -13:23:53.1 11.4713 9.8313 
2016-Apr-05 10:20 18:27:08.64 -13:23:52.3 11.4675 9.8341 
2016-Apr-05 10:25 18:27:08.71 -13:23:51.5 11.4640 9.8370 
2016-Apr-05 10:30 18:27:08.77 -13:23:50.7 11.4607 9.8398 
2016-Apr-05 10:35 18:27:08.84 -13:23:49.8 11.4577 9.8427 
2016-Apr-05 10:40 18:27:08.90 -13:23:49.0 11.4550 9.8455 
2016-Apr-05 10:45 18:27:08.96 -13:23:48.2 11.4525 9.8484 
2016-Apr-05 10:50 18:27:09.03 -13:23:47.4 11.4503 9.8512 
2016-Apr-05 10:55 18:27:09.09 -13:23:46.6 11.4483 9.8541 
2016-Apr-05 11:00 18:27:09.15 -13:23:45.7 11.4465 9.8570 
2016-Apr-05 11:05 18:27:09.22 -13:23:44.9 11.4451 9.8598 
2016-Apr-05 11:10 18:27:09.28 -13:23:44.1 11.4438 9.8627 
2016-Apr-05 11:15 18:27:09.35 -13:23:43.3 11.4429 9.8655 
2016-Apr-05 11:20 18:27:09.41 -13:23:42.5 11.4422 9.8684 
2016-Apr-05 11:25 18:27:09.47 -13:23:41.6 11.4417 9.8712 
2016-Apr-05 11:30 18:27:09.54 -13:23:40.8 11.4415 9.8740 
2016-Apr-05 11:35 18:27:09.60 -13:23:40.0 11.4415 9.8768 
2016-Apr-05 11:40 18:27:09.66 -13:23:39.2 11.4418 9.8796 
2016-Apr-05 11:45 18:27:09.73 -13:23:38.4 11.4424 9.8824 
2016-Apr-05 11:50 18:27:09.79 -13:23:37.5 11.4432 9.8852 
2016-Apr-05 11:55 18:27:09.85 -13:23:36.7 11.4442 9.8880 
2016-Apr-05 12:00 18:27:09.92 -13:23:35.9 11.4455 9.8907 
2016-Apr-05 12:05 18:27:09.98 -13:23:35.1 11.4470 9.8934 
2016-Apr-05 12:10 18:27:10.05 -13:23:34.2 11.4488 9.8962 
2016-Apr-05 12:15 18:27:10.11 -13:23:33.4 11.4508 9.8988 
2016-Apr-05 12:20 18:27:10.17 -13:23:32.6 11.4531 9.9015 
2016-Apr-05 12:25 18:27:10.24 -13:23:31.8 11.4555 9.9042 
2016-Apr-05 12:30 18:27:10.30 -13:23:30.9 11.4583 9.9068 
2016-Apr-05 12:35 18:27:10.36 -13:23:30.1 11.4612 9.9094 
2016-Apr-05 12:40 18:27:10.43 -13:23:29.3 11.4644 9.9120 
2016-Apr-05 12:45 18:27:10.49 -13:23:28.5 11.4678 9.9145 
2016-Apr-05 12:50 18:27:10.56 -13:23:27.6 11.4714 9.9171 
2016-Apr-05 12:55 18:27:10.62 -13:23:26.8 11.4753 9.9195 
2016-Apr-05 13:00 18:27:10.68 -13:23:26.0 11.4794 9.9220 
2016-Apr-05 13:05 18:27:10.75 -13:23:25.2 11.4836 9.9244 
2016-Apr-05 13:10 18:27:10.81 -13:23:24.3 11.4881 9.9268 
2016-Apr-05 13:15 18:27:10.88 -13:23:23.5 11.4928 9.9292 
2016-Apr-05 13:20 18:27:10.94 -13:23:22.7 11.4978 9.9316 
2016-Apr-05 13:25 18:27:11.00 -13:23:21.9 11.5029 9.9339 
2016-Apr-05 13:30 18:27:11.07 -13:23:21.0 11.5082 9.9361 
2016-Apr-05 13:35 18:27:11.13 -13:23:20.2 11.5137 9.9383 
2016-Apr-05 13:40 18:27:11.20 -13:23:19.4 11.5194 9.9405 
2016-Apr-05 13:45 18:27:11.26 -13:23:18.6 11.5253 9.9427 
2016-Apr-05 13:50 18:27:11.32 -13:23:17.7 11.5314 9.9448 
2016-Apr-05 13:55 18:27:11.39 -13:23:16.9 11.5377 9.9469 
2016-Apr-05 14:00 18:27:11.45 -13:23:16.1 11.5441 9.9489 
2016-Apr-05 14:05 18:27:11.52 -13:23:15.3 11.5507 9.9509 
2016-Apr-05 14:10 18:27:11.58 -13:23:14.4 11.5575 9.9528 
2016-Apr-05 14:15 18:27:11.65 -13:23:13.6 11.5644 9.9547 
2016-Apr-05 14:20 18:27:11.71 -13:23:12.8 11.5715 9.9566 
2016-Apr-05 14:25 18:27:11.77 -13:23:11.9 11.5788 9.9584 
2016-Apr-05 14:30 18:27:11.84 -13:23:11.1 11.5862 9.9602 
2016-Apr-05 14:35 18:27:11.90 -13:23:10.3 11.5938 9.9619 
2016-Apr-05 14:40 18:27:11.97 -13:23:09.5 11.6015 9.9636 
2016-Apr-05 14:45 18:27:12.03 -13:23:08.6 11.6093 9.9652 
2016-Apr-05 14:50 18:27:12.10 -13:23:07.8 11.6173 9.9667 
2016-Apr-05 14:55 18:27:12.16 -13:23:07.0 11.6254 9.9683 
2016-Apr-05 15:00 18:27:12.23 -13:23:06.1 11.6336 9.9697 
2016-Apr-05 15:05 18:27:12.29 -13:23:05.3 11.6419 9.9712 
2016-Apr-05 15:10 18:27:12.36 -13:23:04.5 11.6504 9.9725 
2016-Apr-05 15:15 18:27:12.42 -13:23:03.6 11.6590 9.9738 
2016-Apr-05 15:20 18:27:12.49 -13:23:02.8 11.6676 9.9751 
2016-Apr-05 15:25 18:27:12.55 -13:23:02.0 11.6764 9.9763 
2016-Apr-05 15:30 18:27:12.62 -13:23:01.2 11.6853 9.9775 
2016-Apr-05 15:35 18:27:12.68 -13:23:00.3 11.6942 9.9786 
2016-Apr-05 15:40 18:27:12.75 -13:22:59.5 11.7032 9.9796 
2016-Apr-05 15:45 18:27:12.81 -13:22:58.7 11.7124 9.9806 
2016-Apr-05 15:50 18:27:12.88 -13:22:57.8 11.7215 9.9816 
2016-Apr-05 15:55 18:27:12.94 -13:22:57.0 11.7308 9.9825 
2016-Apr-05 16:00 18:27:13.01 -13:22:56.2 11.7401 9.9833 
2016-Apr-05 16:05 18:27:13.07 -13:22:55.3 11.7494 9.9841 
2016-Apr-05 16:10 18:27:13.14 -13:22:54.5 11.7589 9.9848 
2016-Apr-05 16:15 18:27:13.20 -13:22:53.7 11.7683 9.9854 
2016-Apr-05 16:20 18:27:13.27 -13:22:52.9 11.7778 9.9860 
2016-Apr-05 16:25 18:27:13.33 -13:22:52.0 11.7874 9.9866 
2016-Apr-05 16:30 18:27:13.40 -13:22:51.2 11.7969 9.9871 
2016-Apr-05 16:35 18:27:13.46 -13:22:50.4 11.8065 9.9875 
2016-Apr-05 16:40 18:27:13.53 -13:22:49.5 11.8161 9.9879 
2016-Apr-05 16:45 18:27:13.60 -13:22:48.7 11.8257 9.9882 
2016-Apr-05 16:50 18:27:13.66 -13:22:47.9 11.8353 9.9884 
2016-Apr-05 16:55 18:27:13.73 -13:22:47.0 11.8449 9.9886 
2016-Apr-05 17:00 18:27:13.79 -13:22:46.2 11.8545 9.9888 
2016-Apr-05 17:05 18:27:13.86 -13:22:45.4 11.8641 9.9889 
2016-Apr-05 17:10 18:27:13.93 -13:22:44.5 11.8737 9.9889 
2016-Apr-05 17:15 18:27:13.99 -13:22:43.7 11.8833 9.9889 
2016-Apr-05 17:20 18:27:14.06 -13:22:42.9 11.8928 9.9888 
2016-Apr-05 17:25 18:27:14.12 -13:22:42.1 11.9023 9.9887 
2016-Apr-05 17:30 18:27:14.19 -13:22:41.2 11.9118 9.9885 
2016-Apr-05 17:35 18:27:14.26 -13:22:40.4 11.9212 9.9882 
2016-Apr-05 17:40 18:27:14.32 -13:22:39.6 11.9306 9.9879 
2016-Apr-05 17:45 18:27:14.39 -13:22:38.7 11.9399 9.9875 
2016-Apr-05 17:50 18:27:14.46 -13:22:37.9 11.9492 9.9871 
2016-Apr-05 17:55 18:27:14.52 -13:22:37.1 11.9584 9.9866 
2016-Apr-05 18:00 18:27:14.59 -13:22:36.2 11.9675 9.9861 
2016-Apr-05 18:05 18:27:14.66 -13:22:35.4 11.9765 9.9855 
2016-Apr-05 18:10 18:27:14.72 -13:22:34.6 11.9855 9.9848 
2016-Apr-05 18:15 18:27:14.79 -13:22:33.7 11.9943 9.9841 
2016-Apr-05 18:20 18:27:14.86 -13:22:32.9 12.0031 9.9834 
2016-Apr-05 18:25 18:27:14.92 -13:22:32.1 12.0118 9.9826 
2016-Apr-05 18:30 18:27:14.99 -13:22:31.3 12.0204 9.9817 
2016-Apr-05 18:35 18:27:15.06 -13:22:30.4 12.0289 9.9808 
2016-Apr-05 18:40 18:27:15.12 -13:22:29.6 12.0372 9.9799 
2016-Apr-05 18:45 18:27:15.19 -13:22:28.8 12.0455 9.9789 
2016-Apr-05 18:50 18:27:15.26 -13:22:27.9 12.0536 9.9778 
2016-Apr-05 18:55 18:27:15.32 -13:22:27.1 12.0616 9.9767 
2016-Apr-05 19:00 18:27:15.39 -13:22:26.3 12.0694 9.9755 
2016-Apr-05 19:05 18:27:15.46 -13:22:25.4 12.0771 9.9743 
2016-Apr-05 19:10 18:27:15.53 -13:22:24.6 12.0847 9.9731 
2016-Apr-05 19:15 18:27:15.59 -13:22:23.8 12.0922 9.9718 
2016-Apr-05 19:20 18:27:15.66 -13:22:23.0 12.0994 9.9704 
2016-Apr-05 19:25 18:27:15.73 -13:22:22.1 12.1066 9.9690 
2016-Apr-05 19:30 18:27:15.80 -13:22:21.3 12.1135 9.9676 
2016-Apr-05 19:35 18:27:15.86 -13:22:20.5 12.1203 9.9661 
2016-Apr-05 19:40 18:27:15.93 -13:22:19.6 12.1270 9.9646 
2016-Apr-05 19:45 18:27:16.00 -13:22:18.8 12.1334 9.9630 
2016-Apr-05 19:50 18:27:16.07 -13:22:18.0 12.1397 9.9614 
2016-Apr-05 19:55 18:27:16.13 -13:22:17.2 12.1458 9.9597 
2016-Apr-05 20:00 18:27:16.20 -13:22:16.3 12.1517 9.9580 
2016-Apr-05 20:05 18:27:16.27 -13:22:15.5 12.1575 9.9563 
2016-Apr-05 20:10 18:27:16.34 -13:22:14.7 12.1630 9.9545 
2016-Apr-05 20:15 18:27:16.40 -13:22:13.8 12.1683 9.9527 
2016-Apr-05 20:20 18:27:16.47 -13:22:13.0 12.1735 9.9509 
2016-Apr-05 20:25 18:27:16.54 -13:22:12.2 12.1784 9.9490 
2016-Apr-05 20:30 18:27:16.61 -13:22:11.4 12.1832 9.9471 
2016-Apr-05 20:35 18:27:16.67 -13:22:10.5 12.1877 9.9452 
2016-Apr-05 20:40 18:27:16.74 -13:22:09.7 12.1920 9.9432 
2016-Apr-05 20:45 18:27:16.81 -13:22:08.9 12.1961 9.9412 
2016-Apr-05 20:50 18:27:16.88 -13:22:08.0 12.1999 9.9391 
2016-Apr-05 20:55 18:27:16.95 -13:22:07.2 12.2036 9.9371 
2016-Apr-05 21:00 18:27:17.01 -13:22:06.4 12.2070 9.9350 
2016-Apr-05 21:05 18:27:17.08 -13:22:05.6 12.2102 9.9329 
2016-Apr-05 21:10 18:27:17.15 -13:22:04.7 12.2132 9.9307 
2016-Apr-05 21:15 18:27:17.22 -13:22:03.9 12.2159 9.9286 
2016-Apr-05 21:20 18:27:17.29 -13:22:03.1 12.2185 9.9264 
2016-Apr-05 21:25 18:27:17.35 -13:22:02.3 12.2207 9.9242 
2016-Apr-05 21:30 18:27:17.42 -13:22:01.4 12.2228 9.9219 
2016-Apr-05 21:35 18:27:17.49 -13:22:00.6 12.2245 9.9197 
2016-Apr-05 21:40 18:27:17.56 -13:21:59.8 12.2261 9.9174 
2016-Apr-05 21:45 18:27:17.63 -13:21:59.0 12.2274 9.9151 
2016-Apr-05 21:50 18:27:17.69 -13:21:58.1 12.2285 9.9128 
2016-Apr-05 21:55 18:27:17.76 -13:21:57.3 12.2293 9.9105 
2016-Apr-05 22:00 18:27:17.83 -13:21:56.5 12.2298 9.9082 
2016-Apr-05 22:05 18:27:17.90 -13:21:55.7 12.2301 9.9058 
2016-Apr-05 22:10 18:27:17.97 -13:21:54.8 12.2302 9.9035 
2016-Apr-05 22:15 18:27:18.03 -13:21:54.0 12.2300 9.9011 
2016-Apr-05 22:20 18:27:18.10 -13:21:53.2 12.2296 9.8987 
2016-Apr-05 22:25 18:27:18.17 -13:21:52.4 12.2289 9.8964 
2016-Apr-05 22:30 18:27:18.24 -13:21:51.5 12.2279 9.8940 
2016-Apr-05 22:35 18:27:18.31 -13:21:50.7 12.2267 9.8916 
2016-Apr-05 22:40 18:27:18.37 -13:21:49.9 12.2253 9.8892 
2016-Apr-05 22:45 18:27:18.44 -13:21:49.1 12.2236 9.8868 
2016-Apr-05 22:50 18:27:18.51 -13:21:48.3 12.2216 9.8844 
2016-Apr-05 22:55 18:27:18.58 -13:21:47.4 12.2194 9.8820 
2016-Apr-05 23:00 18:27:18.65 -13:21:46.6 12.2169 9.8796 
2016-Apr-05 23:05 18:27:18.71 -13:21:45.8 12.2141 9.8772 
2016-Apr-05 23:10 18:27:18.78 -13:21:45.0 12.2111 9.8748 
2016-Apr-05 23:15 18:27:18.85 -13:21:44.1 12.2079 9.8724 
2016-Apr-05 23:20 18:27:18.92 -13:21:43.3 12.2044 9.8701 
2016-Apr-05 23:25 18:27:18.99 -13:21:42.5 12.2006 9.8677 
2016-Apr-05 23:30 18:27:19.05 -13:21:41.7 12.1966 9.8653 
2016-Apr-05 23:35 18:27:19.12 -13:21:40.9 12.1924 9.8630 
2016-Apr-05 23:40 18:27:19.19 -13:21:40.0 12.1878 9.8606 
2016-Apr-05 23:45 18:27:19.26 -13:21:39.2 12.1831 9.8583 
2016-Apr-05 23:50 18:27:19.32 -13:21:38.4 12.1781 9.8560 
2016-Apr-05 23:55 18:27:19.39 -13:21:37.6 12.1728 9.8537 
2016-Apr-06 00:00 18:27:19.46 -13:21:36.8 12.1673 9.8514 

Note

You may wish to edit the NAME = line to rename the object. The name of the object will be used in SBs as an argument to scan functions such as Track().

NNTLE - Tracking Earth Satellites

NNTLE stands for NASA/NORAD Two-Line Elements. This refers to a standard NASA format for orbital elements for Earth satellites. The first non-comment line of the Catalog must contain FORMAT = NNTLE.

If the FILE keyword is used then one should only give the name of the object in the Catalog as the elements of the orbit are retrieved from the file or URL. Note that the full path name of the file must be given, and the file must have world read permission.

The remainder of the non-comment lines contain the names for one or more satellites and their orbital elements in the NASA/NORAD Two-Line Element format.

When implementing an NNTLE catalog, the scantype function will pass the 3 lines to a program that will calculate positions for the antenna, given the scan start time and duration. The source name is the string that appears on the first of the three lines, and that is what one would pass to the scan function.

Standard Catalogs

Several “standard” catalogs listed in Table~ref{table:catalogs} are available for use within the Green Bank computing system. They are all ASCII files in the directory /home/astro-util/astridcats.

Note that for convenience, these standard catalogs may be referred to within Astrid simply by name, without the .cat extension. e.g.

c = Catalog(kaband_pointing)

The following Catalogs are present as of April 2022. The flux densities of pointing calibrators vary by up to a factor of two on time scales of years at frequencies higher than 8 GHz, so the pointing calibrators will never be good flux calibrators. The main reason for updating their flux densities is to make sure the observer gets a strong-enough pointing calibrator. For genuine flux-density calibration, we recommend observers use the flux densities of 3C123, 3C286, and 3C295 [Perley and Butler, 2017].

Catalog	Description
fluxcal	Calibrators with well-determined flux densities. U.S. Government Printing Office (Usgpo) 2006, The Astronomical Almanac for the year 2006, Washington: U.S. Government Printing Office (USGPO), 2006, U.S. Naval Observatory (USNO), Royal Greenwich Observatory (RGO).
pointing	Condon’s master pointing catalog for the GBT
pf_pointing	Extracted from pointing catalog for the 50 cm band (0.6GHz).
lband_pointing	Extracted from pointing catalog for the 21 cm band (1.4GHz).
sband_pointing	Extracted from pointing catalog for the 10 cm band (3GHz).
cband_pointing	Extracted from pointing catalog for the 6 cm band (6GHz).
xband_pointing	Extracted from pointing catalog for the 3.5 cm band (9GHz).
kuband_pointing	Extracted from pointing catalog for the 2 cm band (14GHz).
kband_pointing	Extracted from pointing catalog for the 1.5 cm band (20GHz).
kaband_pointing	Extracted from pointing catalog for the 9 mm band (32GHz).
qband_pointing	Extracted from pointing catalog for the 7 mm band (43GHz).
wband_pointing	Extracted from pointing catalog for the 3.5mm band (86GHz).
mustang_pointing	Extracted from pointing catalog for the 3.3mm band (90GHz).
HI_strong	Galaxies with strong HI lines, extracted from Rich Fisher’s database
pulsars_all	All 1533 pulsars in the ATNF database as of 26 Aug 2005.
pulsars_all_GBT	All 1054 pulsars visible from Green Bank.
pulsars_brightest_GBT	The brightest pulsars, visible from Green Bank.
pulsars_bright_MSPs_GBT	Bright millisecond pulsars visible from Green Bank.

The GBT pointing catalog has been updated several times to include better positions and more recent flux densities. These changes are described in the PTCS project notes posted at https://safe.nrao.edu/wiki/bin/view/GB/PTCS/ProjectNotes.

Todo

Check if these PTCS project notes can be made available here.

• PTCS-PN58 introduces PCALS4.1 and “gold standard” pointing calibrators for use at higher frequencies

• PTCS-PN66 introduces PCALS4.4, a catalog upgrade incorporating high-frequency flux densities from WMAP5 and accurate positions from the VLBA calibrator surveys through VCS6

• PTCS-PN72 introduces PCALS4.5 with high-frequency flux densities updated by WMAP7, the Planck “Early Release Compact Source Catalog”, and the Australia Telescope AT20G survey.

• PCALS 4.7 adds new 30, 44, 70, and 100 GHz flux densities from the final Planck Catalogue of Compact Sources [Planck Collaboration et al., 2014] and 20 GHz fluxes from [Righini et al., 2012]. There is no PTCS/PN describing this release.

Catalog Functions

Two useful catalog functions are available.

c.keys()

Acts like a Python function that returns a list of all the source names in the Catalog loaded into the variable c, i.e. via c = Catalog('mycatalog'). The value returned can be used in the SB to automatically loop through all the sources in a catalog. Here is an example of how to do this:

c = Catalog(HI_strong)
sourcenames = c.keys()
for s in sourcenames :
    Nod(s,'1','2',120)

c[‘sourcename’][‘keyword’]

Returns the value of the keyword for the named source in the Catalog loaded into the variable c. This function can be used to pass information in the Catalog on to the SB (e.g. specifying different map sizes for different sources/directions).

The c['sourcename']['keyword'] function can be used to get informatio` out of the keyword column of the Catalog for use within the SB. In the following example we get the source’s Declinations and only observe those sources above \(20^\circ\) Declination (note that the coordinates are always returned in degrees):

c = Catalog(lband_pointing)
sourcenames = c.keys()

for s in sourcenames :
    print c[s]['dec']

    if c[s]['dec'] > 20 :
        Nod(s,'1','2',120)

The c[‘sourcename’][‘keyword’] function can also be used to execute more complicated observing strategies. In the following example we have many sources to observe and we desire a different amount of total integration time for each source. To accomplish this we add two new columns to the Catalog. We will call these columns “sourcetime” and “status”. A few lines of the Catalog (let’s call it “mycatalog.cat”) would look like:

head= name ra dec velocity sourcetime status
SrcA  00:01:02  -03:04:05  -22.0  300  done
SrcB  06:07:08  +10:11:12  +56.3  120  waiting

The SB would look like:

Listing 16 Example SB that retrieves information for each source from user-defined columns in the catalog.

c = Catalog('mycatalog.cat')
sourcenames = c.keys()

for s in sourcenames :
    if c[s]['status'] == 'waiting' :
        dwelltime = float(c[s]['sourcetime'])
        Track(s,None,dwelltime)

Note

c['sourcename']['keyword'] will return a string value. That’s why we have to convert dwelltime in Listing 16 to a float value in order to use it as a suitable time argument in the Track() scan function.

Example Catalogs

SPHERICAL

Listing 17 A simple catalog.

# My source list
format=spherical
coordmode=J2000
HEAD = NAME   RA        DEC
Object1  09:56:16.98  +49:16:25.5
Object2  10:56:16.98  +50:16:25.5
Object3  11:56:16.98  +51:16:25.5
Object4  12:56:16.98  +52:16:25.5

Because all the keyword values in Listing 17 use the defaults, the following is equivalent:

Listing 18 A simple catalog using default header keywords and columns.

# My source list
Object1  09:56:16.98  +49:16:25.5
Object2  10:56:16.98  +50:16:25.5
Object3  11:56:16.98  +51:16:25.5
Object4  12:56:16.98  +52:16:25.5

Listing 19 A catalog using the velocity column to specify radial velocity in km/s.

# My source list with radial velocities
format=spherical
coordmode = B1950
head = name   ra      dec          velocity
Object1  09:56:16.98  +49:16:25.5  27.23
Object2  08:56:16.98  +48:16:25.5  28.24
Object3  07:56:16.98  +47:16:25.5  29.25
Object4  06:56:16.98  +45:16:25.5  30.26

Listing 20 A catalog using the “Galactic” coordinate mode and omitting the format= line.

# A list of HII regions
coordmode=Galactic
head= NAME GLON        GLAT     vel       restfreq
G350+.07   350.107    +0.079    42.2235   9816.867
G351+.17   351.613     0.172   -15.553    9487.824
G352-.17   352.393    -0.176   -52.227    9173.323
G352-.36   353.4219   -0.3690   22.335    9487.824

Warning

Setting the velocity or rest frequency in a catalog only changes the values in the LO1 manager. If either value is changed by a large amount, the receiver selection or bandpass filters or the frequency spacing between spectral windows may change. Thus one should re-configure the IF system for a large change in velocity or frequency. The observer should be wary of how much the velocity or rest frequency can change for a particular configuration.

Listing 21 A catalog with user–defined keywords.

# a list of pointing references
format=spherical
coordmode=j2000
head= name    ra         dec         BMIN BMAX  S20    S6
0011-1434 00:11:40.40   -14:34:04.7    15  45   0.17   0.20
0012-3321 00:12:17.96   -33:21:57.8    15 180   0.85   0.18
0012+6551 00:12:37.80   +65:51:10.5    15 360   1.20   0.55
0012+2702 00:12:38.14   +27:02:40.7    15 180   0.60   0.21
0012+3353 00:12:47.3826 +33:53:38.459   0  45   0.08   0.08
0012-3954 00:12:59.9080 -39:54:25.836   0  45   0.49   1.5

Note

You may create custom keywords (or equivalently column headings). These are available within the SB, but are otherwise ignored.

EPHEMERIS

Listing 22 A simple ephemeris catalog.

FORMAT    = EPHEMERIS
NAME      = MyMovingObject
COORDMODE = J2000
VELDEF    = VRAD-LSR
#--------------------------------------------------------------------
2004-07-16 00:10:00  09:56:16.98  +49:16:25.5  27.234234
2004-07-16 00:20:00  09:56:17.76  +49:16:36.2  27.456345
2004-07-16 00:30:00  09:56:18.55  +49:16:46.9  27.568233
2004-07-16 00:40:00  09:56:19.32  +49:16:57.6  27.623423
2004-07-16 00:50:00  09:56:20.10  +49:17:08.3  27.723456
#--------------------------------------------------------------------

Note

The HEAD= line has been omitted because the default is DATE UTC RA DEC VEL.

Listing 23 A more complicated ephemeris catalog for a comet that specifies the coordinate rates.

FORMAT = EPHEMERIS
VELDEF = VRAD-TOP
COORDMODE = J2000
HEAD = date utc ra dec dra ddec vel
# 1: soln ref.= JPL#153
NAME = 2008CM
2015-Dec-30 05:00 09:00:46.65 +13:13:58.0 -1045.1405 -1344.9600 4.8196
2015-Dec-30 05:10 09:00:35.06 +13:10:13.7 -1044.8328 -1344.5100 4.8595
2015-Dec-30 05:20 09:00:23.47 +13:06:29.5 -1044.4856 -1344.0600 4.8997
2015-Dec-30 05:30 09:00:11.88 +13:02:45.3 -1044.0885 -1343.6000 4.9405
2015-Dec-30 05:40 09:00:00.30 +12:59:01.2 -1043.6313 -1343.1400 4.9815
2015-Dec-30 05:50 08:59:48.72 +12:55:17.2 -1043.1244 -1342.6900 5.0230
2015-Dec-30 06:00 08:59:37.15 +12:51:33.3 -1042.5679 -1342.2200 5.0648

Listing 24 An ephemeris catalog for tracking a satellite.

# PRN14 tracking table (angles in degrees)
# visible 01:30 to 3:00 UT

format    = ephemeris
name      = PRN14
coordmode = azel
head=date  utc       az         el
#-----------------------------------------
2004-05-16 01:30:06  103.1822   43.0174
2004-05-16 01:30:14  103.2464   42.9721
2004-05-16 01:30:22  103.3105   42.9268
2004-05-16 01:30:30  103.3745   42.8814
#-----------------------------------------

NNTLE

Listing 25 An example of a valid NNTLE format Catalog file

FORMAT = NNTLE
USERADVEL = 1     # optional keyword
#
OSCAR10
1 14129U          88230.56274695 0.00000042           10000-3 0  3478
2 14129  27.2218 308.9614 6028281 329.3891   6.4794  2.05877164 10960
GPS-0008
1 14189U          88230.24001475 0.00000013                   0  5423
2 14189  63.0801 108.8864 0128028 212.9347 146.3600  2.00555575 37348

It may also be convenient to use TLEs on a file or website as shown in the next two scripts:

Listing 26 An example NNTLE format Catalog file using the FILE keyword

FORMAT    = NNTLE
USERADVEL = 0
FILE      = /home/astro-util/projects/GBTog/other/gps-ops.txt
Name      = 'GPS BIIR-2'

Listing 27 An example NNTLE format Catalog file using the URL keyword

FORMAT    = NNTLE
USERADVEL = 0
URL       = http://www.celestrak.com/NORAD/elements/gps-ops.txt
Name      = 'GPS BIIR-2'

The first set of orbital elements whose name matches the name listed in the file will be used for calculating the satellite position. Note that the generation of tracks for satellites is based on “pyephem”, an implementation of xephem in Python.