
		  *** CRUSH-2: Notes to CRUSH-1.xx users ***

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

			  Last Updated: 18 Jul 2011



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

1. Overview

  1.1 Why Switch?
  1.2 What's (still) Missing?
  1.3 Migrating scripts

2. Reference: Old and New Configurations 




#############################################################################
1. Overview
#############################################################################

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

The old CRUSH is no longer supported (has not been for a while now!), and will 
be phased out completely in time. Thus, all users of CRUSH-1.xx 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. You can then use this document as further reference
for dealing with the different configuration scheme of CRUSH-2.



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


   User Experience
   ---------------

	* Improved algorithms provide better removal of noise signals
	  while keeping more large-scale structure in your maps.

	* Faster reductions (2.5x--20x 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, work with many instruments.

	* 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
   --------------

	* Redesigned from the ground-up. The restructured code makes it easier 
	  to spot bugs and fix them quickly. The new code is much less prone to
	  nasty bugs than CRUSH 1.xx every was.
	
	* Multi-threaded reductions to get through large data sets fast.

	* Smaller memory footprint enables reducing larger datasets than
	  ever.

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




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

   While CRUSH-2 brings you many of the same capabilities as CRUSH-1.xx 
   (and more!), not all features of CRUSH-1.xx have been migrated to the
   new code base of CRUSH-2.

   Most notably, CRUSH-2 still relies on the image manipulation tools of
   CRUSH-1.xx (e.g. 'show', 'imagetool', 'detect'). These work fine (in most
   cases) with the images produced by CRUSH-2. However, the plan is to create
   equivalent tools from within the CRUSH-2 code, both for better integration
   with the reduction, and also to take advantage of its superior code 
   structure. Keep checking future CRUSH-2 releases for status updates.

   Some of the missing aspects in CRUSH-2 are (were) niche features of CRUSH 
   1.xx, which were rarely used by the typical astronomer. Such features will 
   be slow to make it into CRUSH-2 due to their low priority. If there is
   a feature that you are sorely missing, please contact Attila Kovacs
   <attila[AT]submm.caltech.edu> to see if it can be implemented quickly... 

   Here's a quick list of CRUSH-1.xx features not found in CRUSH-2:

	* Native CRUSH-2 image tools (for now, the CRUSH-1.xx tools are
	  bundled).

	* Pointing reductions suggest pointing corrections but do not 
	  automatically display the reduced images and pointing circles (due
	  to the lack of an integrated 'show' tool for CRUSH-2, see above).
	  If you want to look at the image, you have to do this manually
	  via 'show'. 

	* Some output options, like writing 2-D sky spectra, or spatial
	  correlations is not (yet) implemented. Let me know if you need
	  these for your research!

	* Sky noise removal is limited to the common mode and gradients. 
	  Higher order polynomials, available in CRUSH-1.xx, are not 
	  implemented. 
	  In truth, there is no evidence that anything above the linear
	  order exists, or that it would improve on the reduction quality.
	  If you have a problem with baselines, even in 'deep' mode, use
	  'source.filter' instead to reject larger scale (atmospheric) 
	  strucures.

	* No regional correlations in CRUSH-2. See the notes on sky-noise
	  polynomials above for alternatives. 

	* No real-time opacity correction, based on the correlated signals.
	  There is no reason why these should be necessary really. The
	  dropping of this capability may result in an extra source of
	  calibration uncertainty less than 1%. Given that there are much
	  larger uncertainties because of the absolute tau, focus variations,
	  DSOS status, and fridge cycles, the effect is absolutely negligible.




1.3 Migrating Scripts
=====================

   If you have old CRUSH-1.xx reductions scripts that you want to use with
   CRUSH-2, you have to make some adjustments manually before they can be used
   with the latest CRUSH. First, you must insert 'sharc2' as the first command-
   line argument:

	crush sharc2 [...]

   If you are using extra command-line options, you should check in the table
   below for their CRUSH-2 equivalents. Note, that the most commonly used 
   options such as '-faint', '-bright', '-deep', '-outpath' and '-name' have 
   not changed at all, but some options may have.

   Also, you should be aware that the default configuration of CRUSH-2 is not
   identical to the defaults of CRUSH 1.xx. If you have been relying on some
   advanced CRUSH-1.xx switches, you should first check, if anything similar
   is really necessary with CRUSH-2. I.e., try reducing with only the most
   essential options first, and try adding more options gradually, carefully
   evaluating their effect. In all likelihood, CRUSH-2 will achieve better
   results with fewer tweaks from the default settings.




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


Below is a quick overview of the CRUSH-2 keywords corresponding to CRUSH-1.xx
command-line options and equivalent configuration keys. The table is sorted 
case-sensitive alphabetically according to the 1.xx command-line options as
produced by 'crush -help' (even though the neither crush-1.xx or CRUSH-2 is
case sensitive in parsing these keywords!).

Most CRUSH-1.xx settings have their CRUSH-2 equivalent. Often the same key is
used as in 1.xx. In some cases, the key may be renamed, but its behaviour is
the same. In other cases, there exist similar (if not 1:1 equivalent) CRUSH-2
settings that can be used for similar effect.


Table 1. Old and new configuration options/keys

------------------------------------------------------------------------------
CRUSH-1.xx	CRUSH-1.xx key		CRUSH-2
==============================================================================
-13Hz		NOISY_13HZ_ACTION	--- (not needed)
-aclip		MAX_ACCELERATION	aclip
-altaz		ALTAZ=true		altaz (system=horizontal)
-aperture	---			photometry
-atm		ATMOSPHERIC_CORRECTION=true  --- (default)
-average=	AVERAGE_FRAMES		downsample
-beam=		SHARC2_BEAM_FWHM	beam
-blank=		MAP_BLANKING_LEVEL	blank
-bright		LOAD_CONFIG=bright.cfg	bright
-blocksize	BLOCK_SIZE		blocks.size
-blockT=	BLOCK_CORRELATION_T	blocks.resolution (in seconds!)
-chi2		CHI2_REPORTING		---
-chopped=	CHOPPED_OBSERVATION=true  chopped (see also 'detect.chopped')
-compact	---			(default) or forget=extended
-config=	LOAD_CONFIG		config
-correct=	FLUX_CORRECTING_FWHM	--- (see 'source.correct')
-covar=		WRITE_COVARIANCE=true	write.covar
-cutoff=	MAP_CUTOFF_LEVEL	clip
-debug		---			debug
-deep		LOAD_CONFIG=deep.cfg	deep
-default	LOAD_CONFIG=default.cfg	config=default.cfg
-diameter	SOURCE_DIAMETER		sourcesize
-directGains	DIRECT_GAINS=true	(default)
-driftT=	PIXEL_DRIFT_T		drifts.resolution (in seconds!)
-Eblock=	BLOCK_CORRELATION_ESTIMATOR  --- (see 'estimator')
-Ecorr=		CORRELATED_ESTIMATOR	--- (see 'estimator')
-Edrift=	PIXEL_DRIFT_ESTIMATOR	--- (see 'estimator')
-Emap=		MAP_ESTIMATOR		(see 'source.mem')
-Emux=		MUX_ESTIATOR		--- (see 'estimator')
-Eoffset=	OFFSET_ESTIMATOR	--- (see 'estimator')
-ErowDrift=	ROW_DRIFT_ESTIMATOR	--- (see 'estimator')
-edge=		IGNORE_ARRAY_EDGES	--- (not needed, \
					     use 'flag' if really want it)
-efficiency	---			beammap or source.coupling
-estimator=	DEFAULT_ESTIMATOR	estimator
-excessLoad=	DEFAULT_EXCESS_LOAD	excessLoad
-extended	---			extended
-extBlank	EXTENDED_FILTER_BLANKING  source.filter.blank
-extFilter=	EXTENDED_FILTER_SCALE	source.filter, source.filter.fwhm
...		EXTENDED_FILTER_TYPE	source.filter.type
-FAZO=		---			fazo
-FZAO=		---			fzao
-faint		LOAD_CONFIG=faint.cfg	faint
-fftFilter=	---			source.filter, source.filter.type, \ 
					source.filter.fwhm	
-flagFraction	FLAG_NOISY_PIXEL_FRACTION  ---
-flags		EXCLUDE_FLAGS		---
-gainrounds	GAIN_ITERATIONS		---
-gainGoal	GAIN_CONVERGENCE_GOAL	---
-gains		---			write.pixeldata
-gapOK=		TOLERATE_TIMING_GAPS	(see 'nogaps')
-grid=		MAP_GRID_RESOLUTION	grid
-hipass		HIGH_PASS_FILTER	hipass
-histogram	WRITE_HISTOGRAM=true	---
-histbin	HISTOGRAM_RESOLUTION	---
-Iaccel=n	ACCELERATION_RESPONSE_TURN  iteration.[n]accel
-Ibeam=n	BEAM_EFFICIENCY_TURN	iteration.[n]source.coupling
-Iblock=n	BLOCK_CORRELATION_TURN	iteration.[n]blocks
-Ichop=n	CHOP_RESIDUAL_TURN	forget=chopper + iteration.[n]chopper
-Icorr=n	CORRELATED_TURN		forget=array + iteration.[n]array
-Idespike=n	DESPIKE_TURN		forget=despike + iteration.[n]despike
-Idrift=n	PIXEL_DRIFT_TURN	forget=drifts + iteration.[n]drifts
-Iextended=n	EXTENDED_PRESERVE_TURNS	--- (not needed)
-Ifidel=n	MAP_FAITHFUL_TURN	iteration.[n]blacklist=clip
-Igain=n	GAIN_TURN		array.nogains + \
					iteration.[n]forget=array.nogains
-Imap=n		MAP_TURN		forget=source + iteration.[n]source
-Imux=n		MUX_TURN		iteration.[n]mux
-Inonlinear=n	NON_LINEAR_TURN		---
-Ioffset=n	OFFSET_TURN		iteration.[n]offsets
-Ipweight=n	PIXEL_WEIGHT_TURN	forget=weighting + \
					iteration.[n]weighting
-Iregion=n	REGIONAL_CORRELATION_TURN  --- (see 'source.filter' \
					       and 'iteration')
-IrowDrift=n	ROW_DRIFT_TURN		forget=drifts + iteration.[n]drifts
-Isky=n		SKY_POLYNOMIAL_TURN	forget=gradients + \
					iteration.[n]gradients
-Ispectal=n	SPECTRAL_ANALYSIS_TURN	--- (see 'whiten')
-Ispike=n				forget=despike + iteration.[n]despike
-ItauAdjust=n	TAU_ADJUST_TURN		---
-Itemporal=n	TEMPORAL_ANALYSIS_TURN	iteration.[n]despike.method=features
-Itweight=n	TIME_WEIGHTING_TURN	iteration.[n]weighting.frames
-index		---			---
-info		---			---
-Jy=		MAP_VOLTS_PER_JY	jansky 
-lambda=	MEM_LAMBDA		source.mem.lambda
-linear		LINEAR_RESPONSE=true		(default)
-log		---			obslog, obslog.format
-lookup		COORDINATE_LOOKUP	indexing, indexing.saturation
-MaiTau=	MAI_TAU			maitau.server			\
					(see also 'maitau.fallback')
-map=		---			--- (use 'ordering')
-mapJy		---			--- (see 'jansky')
-mapWeight=	MAP_ROBUST_WEIGHT=true	weighting.scans			\
					(see also 'weighting.scans.method')
-mask=		---			---
-maxNoise=	MAX_RELATIVE_PIXEL_NOISE  weighting.noiserange
-maxRMS=	MAX_RELATIVE_NOISE	noiseclip
-maxSpectral=	MAX_SPEXTRAL_FEATURE	--- (see 'whiten.level')
-maxTemporal=	MAX_TEMPORAL_FEATURE	--- (see 'despike.level')
-minDOF=	MIN_DEGREES_OF_FREEDOM	---
-minExp=	MIN_RELATIVE_EXPOSURE	exposureclip
-minIntT=	MIN_INTEGRATION_TIME	subscan.minlength
-minPixels=	MAP_MIN_PIXELS		mappingpixels 			\
					(see also 'mappingfraction')
-model=		---			source.model
-models		WRITE_SCAN_MODELS=true	write.signals
-muxT=		MUX_T			mux.resolution (in seconds!)
-name=		---			name
-noatm		ATMOSPHERIC_CORRECTION=false  tau=0.0 or forget=tau
-noflag		---			---
-nogains	---			forget=write.pixeldata
-nohist		WRITE_HISOGRAM=false	---
-noindex	---			---
-nonlinear	LINEAR_RESPONSE=false	---
-nomodels	WRITE_MODELS=false	forget=write.pixeldata
-noreorder	PIPELINE_AUTO_REORDER=false  --- (see 'ordering')
-noresiduals	---			forget=write.ascii
-noshow		SHOW_FINAL_MAP=false 	---
-nospacial	---			---
-out=		---			outpath + name
-outpath=	REDUCED_MAP_PATH	outpath
-path=		RAW_DATA_PATH		datapath
-pcenter=	POINTING_CENTER		pcenter
-pixelCoeffs=	NONLINEARITY_COEFFICIENTS  response
-pixelData=	PIXEL_DATA		pixeldata
-planetary	PLANETARY=TRUE		moving
-platescale=	SHARC2_PIXEL_SIZE	pixelsize
-point		LOAD_CONFIG=point.cfg	point
-precess=	REDUCED_MAP_EPOCH	---
-prefix=	RAW_DATA_PREFIX		--- (not needed)
-projection=	MAP_PROJECTION		projection
-pwRange=	PIXEL_WEIGHT_RANGE	--- (see 'whiten.proberange')
-radec		ALTAZ=false		radec (system=equatorial)
-rcenter	ROTATION_CENTER		rcenter
-regionalT=	REGIONAL_CORRELATION_T	---
-regionType=	REGIONAL_CORRELATION_FORM  --- 
-regionSize=	REGIONAL_CORRELATION_SIZE  --- (see 'source.filter.fwhm')
-reorder	PIPELINE_AUTO_REORDER=true --- (see 'ordering')
-residuals	---			write.ascii
-reweight=	MAP_FINAL_REWEIGHT	('true' is default)
-rot0=		ROTATOR_ZERO		rot0
-rotator=	---			rotation
-rounds=	ITERATIONS		rounds			
-rowDriftT=	ROW_DRIFT_T		rows.resolution (in seconds!)
-scanmaps	WRITE_SCAN_MAPS		scanmaps
-scale=		---			scale
-scramble	---			scramble
-show		SHOW_FINAL_MAP=true	show
-skyOrder=	SKY_POLYNOMIAL_ORDER	--- (see 'source.filter')
-skySpectrum=	---			---
-skyT=		SKY_POLYNOMIAL_T	gradients.resolution (in seconds!)
-slice=		---			---
-smear=		CHOPPER_MAX_SMEAR	--- (see 'vclip')
-smooth=	MAP_SMOOTHING		(see 'smooth')
-spacial	---			---
-spectrum=	---			write.spectrum, write.spectrum.size
-spikelevel=	DESPIKE_LEVEL		despike.level
-spikefraction=	REJECT_SPIKE_FRACTION	despike.flagfraction
-static		PLANETARY=false		(forget=moving)
-TCscale=	---			--- (see 'correlated.<?>.resolution')
-tau=id:value	---			tau.id=value \
					(tau, tau.225GHz, tau.350um, tau.pwv)
-tauScale=id(a,b)  DEFINE_TAU		tau.id.a, tau.id.b
-temporalT=	TEMPORAL_ANALYSIS_MIN_T	despike.width (in seconds!)
-unit=		MAP_UNIT		unit
-vclip=		MIN_SCAN_SPEED		vclip
-version	---			--- (run crush without an argument)
-weightT=	TIME_WEIGHT_T		weighting.frames.resolution (in sec!).
-width13Hz=	FILTER_13HZ_WIDTH	---
------------------------------------------------------------------------------
Copyright (C)2010 -- Attila Kovacs <attila[AT]submm.caltech.edu>
