
		  *** CRUSH-2: Notes to minicrush users ***

			        Attila Kovacs
			  <attila[AT]submm.caltech.edu>

			  Last Updated: 21 Aug 2010



Table of Contents
=================

1. Overview

  1.1 Why Switch?
  1.2 What's (still) Missing?
  1.3 RCPs by the Date
  1.4 Migrating scripts

2. Reference: Old and New Configurations 




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1. Overview
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The purpose of this document is to highlight the differences between minicrush,
and the new CRUSH-2, and thus help users transition to the new software. 

minicrush is no longer supported, and will be phased out completely in time. 
Thus, all minicrush users are strongly encouraged to switch to the new release 
as soon as possible. 

After glancing at this document, you should read the first Section ('Getting 
Started') of the CRUSH-2 User's Guide ('README') to familiarize yourself 
with the new version.


1.1 Why Switch?
===============	


   User Experience
   ---------------
   
	* Skydip, beammap, and pointing/calibration reductions.

	* Faster reductions (~2-3x faster, depending on machine and
	  configuration).

	* More transparent and versatile configuration capability. Do what
	  you want, when you want, and how you want.

	* The same CRUSH, same options, not just for the APEX cameras!

	* Up-to-date documentation (online and off-line), so you are never
	  lost!

	* Code support. CRUSH-2 is the only CRUSH that is being actively
	  developed and supported. So if you find problems, they can be fixed
	  quickly!

	

   Under the Hood
   --------------

	* Smaller memory footprint enables reducing larger datasets than
	  ever.

	* Hierarchical configuration with conditional settings allows for
	  smarter 'scripting'.



1.2 What's (still) Missing?
===========================

   CRUSH-2 grew out of minicrush. Thus, most minicrush features also exist
   in CRUSH-2, often with more polish and refinement, as well as additional
   versatility. The main features that are missing:

      * The data 'simulator' of minicrush is not (yet) reproduced for CRUSH-2. 
	Moreover, because CRUSH-2 uses more information from the data than what
	is created/updated by the minicrush simulator, you are advised against 
	using the minicrush simulator to generate test data for CRUSH-2.

        The CRUSH-2 simulator should become available in one of the upcoming 
   	releases in the not too distant future. There are also plans to add a 
   	'shadow' reduction mode, in which a simulated source undergoes
   	*exacly* the same reduction steps as the real data, s.t. the points
   	source profiles of the reduction can be determined accurately.

   Keep checking back to see when these features become available.



1.3 RCPs by the Date
====================

   Both minicrush and CRUSH-2 can specify RCP files by date. However, they
   achieve this differently. Since minicrush did not have date-specific
   configuration per se, it relied on a file 'rcps.dat' to provide a lookup
   of rcp files by MJD date ranges. This file had entries like:

	54372.0	54391.0	laboca-2007-10.rcp

   specifying that 'laboca-2007-10.rcp' (in the appropriare instrument 
   subdirectory of minicrush) should be used between MJD dates of 54372.0 and 
   54391.0.

   Because CRUSH-2 provides the ability of conditionally setting properties
   by date (both MJD date and calendar date!), there is no longer a need for
   such a lookup file. Instead, the date-specific RCP lookup is defined in
   <instrument>/default.cfg. The equivalent configuration to the above is
   achieved by:

	mjd.[54372.0--54391.0] rcp {$CRUSH}/laboca/laboca-2007-10.rcp

   (Note, that because the full path to the file is given, the RCP does not
   necessarily have to reside in the laboca subdirectory of crush-2!)
   MJDs are nice for astronomy, but not very meaningful to humans. Thus,
   The same can be defined by easier-to-understand calendar dates:

	date.[2007.09.29--2007.10.17] rcp {$CRUSH}/laboca/laboca-2007-10.rcp

    Thus, if you would like to add RCP information for dates beyond the ones
    already defined in your CRUSH-2 distribution, simply add lines, like
    one of the last two above into the 'default.cfg' file inside the 
    appropriate instrument subdirectory.	



1.4 Migrating Scripts
=====================

   The CRUSH-2 configuration system is basically just an evolved version of 
   that of minicrush. Thus, most configuration options look the same, and 
   behave the same as in minicrush. However, a few have changed. Either, 
   because in the hierarchical configuration of CRUSH-2 it made better sense 
   to specify these as sub-options of a group, or to provide simplification 
   otherwise. 

   For example, the option 'despike=absolute,6.0' of minicrush at once 
   activated despiking, chose the 'absolute' method of searching for spikes, 
   and specified excursions larger than 6.0-sigma to be flagged. This was 
   great if you wanted to achieve all three at once, but the syntax did not
   allow for changing just one aspect of despiking, while leaving whatever
   setting was defined for the other two. Thus, it made more sense to break
   the 3 functions into 3 separate settings: 'despike' to activate, 
   'despike.method' to chose the algorithm, and 'despike.level' to set the
   critical significance. This is the approach used in CRUSH-2.

   If you want to migrate your existing minicrush reduction scripts to
   CRUSH-2, please refer to the table below, to see what you have to change
   in your scripts to make them work with CRUSH-2.

   You should also understand that the default settings of CRUSH-2, while
   similar, are not identical to those in minicrush. It is possible that you
   will find that certain overriders you used in minicrush reductions may
   no longer be necessary, while you may opt to use others, which you
   did not require before. As such, you should proceed with caution, when
   migrating old scripts with some more advanced settings.






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2. Reference: Old and New Configurations
#############################################################################

Below you will find a summary of all the minicrush options that have changed, 
listed alphabetically, with their CRUSH-2 equivalent (if any) shown to the
right.


Table 1. List of options whose name/usage has changed since minicrush.

------------------------------------------------------------------------------
minicrush option		CRUSH-2 option
==============================================================================	
center				pointing
chopoffsets			chopped (automatic)
decorrelate			array (i.e. correlated.obs-channels)
despike=<method>,<level>	despike.method=<method> 
				  + despike.level=<level>
				  + despike
extendedopts			[extended] (see conditionals in README.)
filter				source.filter
filter=<type>,<blank>		source.filter.type=<type>
				  + source.filter.blank=<blank> 
				  + source.filter	
framespikes			despike.framespikes
gains=<type>			gains.estimator=<type> 
				  + gains
intermediatemaps		source.intermediates
iteration.n=key:value		iteration.[n]key=value
iterations.clear		remove=iteration
jansky				jansky + jansky.inverse (!)
maxHe3rms			He3.maxrms
MEM.lambda			source.mem.lambda
nefd-range			---
relative-noise-range		weighting.noiserange
scanmap-correction		source.correct		
scanmap-redundancy		source.redundancy
scanmapdespike			source.despike
scanweighting			weighting.scans
sky				gradients
skydipfactor			---
sourcemap			source
sourcemap=MEM			source.MEM
				  + source
sourcemap=nosync		source.nosync
				  + source
spikecount			despike.flagcount
spikefraction			despike.flagfraction
spikewidth			despike.width	
time-weight-range		weighting.frames.noiserange
time-weighting			weighting.frames 
time-weighting=<dt>		weighting.frames.resolution=<dt>
				  + weighting.frames
weighting=<method>		weighting.method=<method> 
				  + weighting
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Copyright (C)2010 Attila Kovacs -- <attila[AT]submm.caltech.edu>
