#!/usr/bin/perl

#======================================================================

#                    M K P R O F I L E 

#                    doc: Sun Jan 19 18:55:26 2003

#                    (c) 2003 A.M. Thurnherr

#======================================================================

# Make an LADCP Profile by Integrating W (similar to Firing's scan*).

# HISTORY:

#	Jan 19, 2003: - written in order to test the RDI libs

#	Jan 20, 2003: - added ensemble number

#	Jan 21, 2003: - added horizontal integration

#	Jan 22, 2003: - corrected magnetic declination

#	Jan 23, 2003: - added -F)ilter

#	Jan 24, 2003: - added more %PARAMs; started integration from 1st bin

#				  - added -g, -f, battery status

#	Jan 25, 2003: - added more %PARAMs

#	Feb  1, 2003: - BUG: bottom-track quality checking was bad

#	Feb  8, 2003: - allowed for array-indices on -f

#	Feb  9, 2003: - added 50% goodvelbin

#				  - removed unknown-field err on -f to allow -f W

#	Feb 10, 2003: - changed initialization depth to 0m

#				  - changed %bottom_depth to %max_depth

#	Feb 11, 2003: - changed sign of magnetic declination

#	Feb 12, 2003: - corrected BT-range scaling

#	Feb 14, 2003: - added %pinging_hours, %min_range

#				  - removed magnetic declination from default

#	Feb 26, 2004: - added earth coordinates

#	Mar  3, 2004: - removed requirement for -M on !-Q

#				  - corrected range-stats on earth coordinates

#	Mar  4, 2004: - added number of ensebles to output

#	Mar 11, 2004: - BUG: rename ACD -> ADC

#	Mar 12, 2004: - added %bottom_xmit_{current|voltage}

#	Mar 16, 2004: - BUG: on -M u/v/x/y were wrong

#	Mar 17, 2004: - added error estimates on u/v/x/y

#				  - removed battery stuff (has to be done btw casts)

#	Mar 18, 2004: - totally re-did u/v integration

#	Mar 19, 2004: - re-designed u/v uncertainty estimation

#	Mar 28, 2004: - added MEAN_CORRELATION, MEAN_ECHO_AMPLITUDE

#	Sep 15, 2005: - changed BinRead library name

#				  - made max gap length variable

#	Sep 16, 2005: - re-did u,v,w uncertainties

#	Nov  8, 2005: - UNIXTIME => UNIX_TIME

#				  - added unix_time, secno, z_BT to default output

#	Dec  1, 2005: - moved profile-building code to [RDI_utils.pl]

#				  - changed -f syntax to allow name=FIELD

#				  - added %bin1_dist, %bin_length

#	Dec  8, 2005: - remove spaces from -f argument to allow multiline

#				    definitions in Makefiles

#	Nov 13, 2006: - BUG: end-of-cast depth had not been reported correctly

#				  - cosmetics

#	Nov 30, 2007: - adapted to 3-beam solutions

#	Dec 11, 2007: - adapted to earlier modifications (Sep 2007) of

#					[RDI_BB_Read.pl]

#	Dec 14, 2007: - replaced z by depth

#	Dec 17, 2007: - BUG: downcast flag was set incorrectly

#	Jan 24, 2008: - rotation had been output as degrees/s; to make it more

#				    consistent with pitch/roll, I changed it to simple degrees

#				  - added net rotations [deployment]/down/up/[recovery]

#	Apr  9, 2008: - added profile -B)ottom depth

#				  - BUG: depth of first bin was reported as beginning of cast

#	Oct 24, 2008: - added RANGE and RANGE_BINS fields

#	Mar 18, 2009: - BUG: pitch/roll calculation had typo

#				  - calc pitch/roll separately for down-/upcasts

#				  - removed approximations in pitch/roll calcs

#	Jul 30, 2009: - typo '<' removed from output

#				  - NaN => nan

#	Dec  8, 2010: - added zmax/zend labels to output

#	Dec 10, 2010: - made mkProfile exit with status 0 if no good ens found but -Q is set

#	Dec 19, 2010: - finally made -A default and activated output file

#	Jan  5, 2011: - made no-good-ensembles found test much more robust

#	Jun 22, 2011: - added bandwith/power warnings

#				  - added ping-interval calculation

#				  - BUG: post-recovery rotations were always zero

#	Sep  9, 2011: - BUG: range calculation for Earth coordinate data included bins without

#						 valid velocities

#	Sep 21, 2010: - added %rms_heave_acceleration

#	Apr 12, 2013: - added -p

#	May 10, 2013: - BUG: mkProfile bombed when ADCP file is truncated at deepest location

#	May 14, 2013: - added heading to output

#				  - added err_vel to output

#				  - finally removed -d/-g

#	Nov 25, 2013: - expunged checkEnsemble

#	Feb 13, 2014: - added support set_range_lim()

#	Mar  4, 2014: - added support to allow missing PITCH/ROLL/HEADING values

#	May 24, 2014: - finally added (gimbal-)pitch & roll to default output

#				  - renamed heading to hdg and pitchroll to tilt

#	Mar 22, 2015: - made it work for moored time series as well

#	Mar 17, 2015: - adapted to new Getopt library

#				  - removed warning

#	Sep 12, 2016: - added %PD0_file

# NOTES:

#	- the battery values are based on transmission voltages (different

#	  from battery voltages) and reported without units (raw 8-bit a2d

#	  values)

#	- -B with the CTD max depth can be used to linearly scale the depths;

#	  even so, the profile can have negative depths, in particular when

#	  the CTD is sent to a shallow depth first and then returned to the surface

#	  before beginning the cast

#	- in one case that I looked at (Anslope ][, cast 82), there are large

#	  depth errors, even when -B is used

#	- this utility works only approximately for uplookers (profile is

#	  roughly ok, but apparently contaminated by surface reflection,

#	  but stats are not ok; e.g. NBP0402 037U.prof)

$0 =~ m{(.*)/[^/]+}; 

require "$1/RDI_BB_Read.pl";

require "$1/RDI_Coords.pl";

require "$1/RDI_Utils.pl";

use Getopt::Std;

$USAGE = "$0 @ARGV";

die("Usage: $0 " .

	"[-Q)uiet] [-F)ilter <script>] " .

	"[require -4)-beam solutions] [-d)iscard <beam#>] [apply beamvel-m)ask <file>] " .

	"[-r)ef-layer <bin|1,bin|6>] [-n) vels <min|2>] " .

	"[-e)rr-vel <max[0.1]] [-c)orrelation <min>] [-p)ct-good <min[100]>] " .

	"[max -g)ap <len>] " .

	"[output -f)ields <field[,...]> " .

	"[-M)agnetic <declination>] [profile -B)ottom <depth>] " .

	"<RDI file>\n")

		unless (&getopts("4AB:F:M:Qd:g:r:n:e:c:f:m:p:") && @ARGV == 1);

$RDI_Coords::minValidVels = 4 if ($opt_4);			# no 3-beam solutions

require $opt_F if defined($opt_F);					# load filter

$opt_r = "1,6" 	unless defined($opt_r);				# defaults

$opt_n = 2	   	unless defined($opt_n);

$opt_e = 0.1   	unless defined($opt_e);

$opt_c = 70	   	unless defined($opt_c);

$opt_g = 120	unless defined($opt_g);

$opt_p = 100	unless defined($opt_p);

($minb,$maxb) = split(',',$opt_r);					# reference layer

die("$0: can't decode -r $opt_r\n") unless defined($maxb);

print(STDERR "Reading $ARGV[0]...");				# read data

readData($ARGV[0],\%dta);

print(STDERR "done\n");

die("$ARGV[0]: not enough bins for choice of -r\n")	# enough bins?

	unless ($dta{N_BINS} >= $maxb);

if ($dta{BEAM_COORDINATES}) {						# coords used

	$beamCoords = 1;

} elsif (!$dta{EARTH_COORDINATES}) {

	die("$ARGV[0]: only beam and earth coordinates implemented so far\n");

}

if (defined($opt_m) && -r $opt_m) {

	die("$ARGV[0]: -m only implemented for data collected in beam coordinates\n")

		unless ($beamCoords);

	print(STDERR "Masking beam velocities as prescribed in $opt_m...");

	open(BVM,$opt_m) || die("$opt_m: $!\n");

	while (<BVM>) {

		s/#.*//;

		s/^\s*$//;

		next if ($_ eq '');

		my($fe,$te,$db) = split;

		die("$opt_m: cannot decode $_\n")

			unless (numberp($fe) && numberp($te) && $te>=$fe && $db>=1 && $db<=4);

		die("$0: assertion failed")

			unless ($dta{ENSEMBLE}[$fe-1]->{NUMBER} == $fe &&

					$dta{ENSEMBLE}[$te-1]->{NUMBER} == $te);

		for (my($ens)=$fe-1; $ens<=$te-1; $ens++) {

			$nens++;

			for (my($bin)=0; $bin<$dta{N_BINS}; $bin++) {

				undef($dta{ENSEMBLE}[$ens]->{VELOCITY}[$bin][$db-1]);

			}

	    }       

    }

	close(BVM);

	print(STDERR " $nens ensembles edited\n");

}

if (defined($opt_d)) {								# discard entire beam

	die("$ARGV[0]: -d only implemented for data collected in beam coordinates\n")

		unless ($beamCoords);

	print(STDERR "Discarding beam-$opt_d velocities...");

    for (my($ens)=0; $ens<=$#{$dta{ENSEMBLE}}; $ens++) {

        for (my($bin)=0; $bin<$dta{N_BINS}; $bin++) {

            undef($dta{ENSEMBLE}[$ens]->{VELOCITY}[$bin][$opt_d-1]);

        }

    }       

	print(STDERR "done\n");

}

if (defined($opt_M)) {								# magnetic declination

	$dta{HEADING_BIAS} = -1*$opt_M;

} else {

	$dta{HEADING_BIAS} = 0;

}

ensure_BT_RANGE(\%dta);								# set BT_RANGE field if it is missing (old firmware bug)

if ($opt_f) {										# additional fields

	@f = split(',',$opt_f);

	foreach $f (@f) {

		$f =~ s/\s//g;								# remove spaces

		@def = split('=',$f);

		if (@def == 2) {							# name=field

			$addFields .= " {$def[0]}";

			$f = $def[1];

		} else {									# field

			$addFields .= " {$f}";

		}

	}

#	print(STDERR "addFields = $addFields\n");

#	print(STDERR "\@f = @f\n");

}

#======================================================================

# Step 0: Check data & Calculate Ping Rates

#======================================================================

unless ($dta{NARROW_BANDWIDTH}) {

	print(STDERR "WARNING: $0 WIDE BANDWIDTH!\n");

}

unless ($dta{TRANSMIT_POWER_HIGH}) {

	print(STDERR "WARNING: $0 LOW TRANSMIT POWER!\n");

}

printf(STDERR "# of ensembles        : %d\n",scalar(@{$dta{ENSEMBLE}}));

my($sdt1,$sdt2,$ndt);

my($mindt1) = my($mindt2) = 9e99;

my($maxdt1) = my($maxdt2) = 0;

for (my($e)=2; $e<=$#{$dta{ENSEMBLE}}; $e+=2,$ndt++) {

	my($dt1) = $dta{ENSEMBLE}[$e-1]->{UNIX_TIME} - $dta{ENSEMBLE}[$e-2]->{UNIX_TIME};

	my($dt2) = $dta{ENSEMBLE}[$e-0]->{UNIX_TIME} - $dta{ENSEMBLE}[$e-1]->{UNIX_TIME};

	$mindt1 = $dt1 if ($dt1 < $mindt1);

	$mindt2 = $dt2 if ($dt2 < $mindt2);

	$maxdt1 = $dt1 if ($dt1 > $maxdt1);

	$maxdt2 = $dt2 if ($dt2 > $maxdt2);

	$sdt1 += $dt1; $sdt2 += $dt2;

}

printf(STDERR "Ping intervals        : %.1fs/%.1fs",$sdt1/$ndt,$sdt2/$ndt);

if ($maxdt1-$mindt1>=0.1 || $maxdt2-$mindt2>=0.1) {

	printf(STDERR " (%.1fs-%.1fs/%.1fs-%.1fs)\n",$mindt1,$maxdt1,$mindt2,$maxdt2);

} else {

	print(STDERR "\n");

}

#======================================================================

# Step 1: Integrate w & determine water depth 

#======================================================================

($firstgood,$lastgood,$atbottom,$w_gap_time,$zErr,$maxz,$rms_heave_accel) =

	mk_prof(\%dta,0,$opt_F,$minb,$maxb,$opt_c,$opt_e,$opt_g,$opt_p);

if ($lastgood == $atbottom) {

	print(STDERR "$ARGV[0]: truncated file (ends at max depth)\n")

} elsif (($atbottom > $firstgood) && ($lastgood > $atbottom)) {

	# all good

} elsif ($lastgood > $firstgood) {

	print(STDERR "$ARGV[0]: no bottom depth found\n")

		unless ($atbottom > 0);

} else {

	if ($opt_Q) {

		print(STDERR "$ARGV[0]: no valid cast data found\n");

		exit(0);

    } else {

		die(sprintf("$ARGV[0]: no valid cast data found (firstgood=%d atbottom=%d lastgood=%d)\n",$firstgood,$atbottom,$lastgood));

	}

}

if (defined($opt_B)) {										# scale Z

	my($zscale) = $opt_B / ($dta{ENSEMBLE}[$atbottom]->{DEPTH} -# downcast

				     	    $dta{ENSEMBLE}[$firstgood]->{DEPTH});

#	printf(STDERR "scaling downcast depths by %.2f\n",$zscale);

	for (my($e)=$firstgood; $e<$atbottom; $e++) {

		next unless defined($dta{ENSEMBLE}[$e]->{DEPTH});

		$dta{ENSEMBLE}[$e]->{DEPTH} =

			$dta{ENSEMBLE}[$firstgood]->{DEPTH} + $zscale *

				($dta{ENSEMBLE}[$e]->{DEPTH}-$dta{ENSEMBLE}[$firstgood]->{DEPTH});

	}

	$zscale = $opt_B / ($dta{ENSEMBLE}[$atbottom]->{DEPTH} -	# upcast

				 		$dta{ENSEMBLE}[$lastgood]->{DEPTH});

#	printf(STDERR "scaling upcast depths by %.2f\n",$zscale);

	for (my($e)=$atbottom; $e<=$lastgood; $e++) {

		next unless defined($dta{ENSEMBLE}[$e]->{DEPTH});

		$dta{ENSEMBLE}[$e]->{DEPTH} =

			$dta{ENSEMBLE}[$firstgood]->{DEPTH} + $zscale *

				($dta{ENSEMBLE}[$e]->{DEPTH}-$dta{ENSEMBLE}[$lastgood]->{DEPTH});

	}

}

set_range_lim(\%dta);										# set {range_lim} field

($water_depth,$sig_wd) =									# sea bed

	find_seabed(\%dta,$atbottom,$beamCoords);

#======================================================================

# Step 2: Integrate u & v

#======================================================================

sub ref_lr_uv($$$)									# calc ref-level u/v

{

	my($ens,$z,$water_depth) = @_;

	my($i,$n,@v,@goodU,@goodV);

	$water_depth = 99999 unless defined($water_depth);

	for ($i=$minb; $i<=$maxb; $i++) {

		next if ($dta{ENSEMBLE}[$ens]->{CORRELATION}[$i][0] < $opt_c ||

				 $dta{ENSEMBLE}[$ens]->{CORRELATION}[$i][1] < $opt_c ||

				 $dta{ENSEMBLE}[$ens]->{CORRELATION}[$i][2] < $opt_c ||

				 $dta{ENSEMBLE}[$ens]->{CORRELATION}[$i][3] < $opt_c);

		if ($beamCoords) {

			next if ($dta{ENSEMBLE}[$ens]->{PERCENT_GOOD}[$i][0] < 100 ||

					 $dta{ENSEMBLE}[$ens]->{PERCENT_GOOD}[$i][1] < 100 ||

					 $dta{ENSEMBLE}[$ens]->{PERCENT_GOOD}[$i][2] < 100 ||

					 $dta{ENSEMBLE}[$ens]->{PERCENT_GOOD}[$i][3] < 100);

			@v = velInstrumentToEarth(\%dta,$ens,

					velBeamToInstrument(\%dta,

						@{$dta{ENSEMBLE}[$ens]->{VELOCITY}[$i]}));

		} else {

			next if ($dta{ENSEMBLE}[$ens]->{PERCENT_GOOD}[$i][0] > 0 ||

					 $dta{ENSEMBLE}[$ens]->{PERCENT_GOOD}[$i][1] > 0 ||

					 $dta{ENSEMBLE}[$ens]->{PERCENT_GOOD}[$i][2] > 0 ||

					 $dta{ENSEMBLE}[$ens]->{PERCENT_GOOD}[$i][3] < 100);

			@v = velApplyHdgBias(\%dta,$ens,

					@{$dta{ENSEMBLE}[$ens]->{VELOCITY}[$i]});

		}

		next if (!defined($v[3]) || abs($v[3]) > $opt_e);

#		Martin's BT routines show strong shear just above sea bed

#		=> skip lowest 20m.

		if (defined($v[0])) {							# valid u,v

			if ($dta{ENSEMBLE}[$ens]->{XDUCER_FACING_UP}) {

				if ($z - $dta{DISTANCE_TO_BIN1_CENTER}

					   - $i*$dta{BIN_LENGTH} > 0) {

					push(@goodU,$v[0]); push(@goodV,$v[1]);

					$dta{ENSEMBLE}[$ens]->{U} += $v[0];

					$dta{ENSEMBLE}[$ens]->{V} += $v[1];

					$n++;

			   }

			} else {

				if ($z + $dta{DISTANCE_TO_BIN1_CENTER}

					   + $i*$dta{BIN_LENGTH} < $water_depth-20) {

					push(@goodU,$v[0]); push(@goodV,$v[1]);

					$dta{ENSEMBLE}[$ens]->{U} += $v[0];

					$dta{ENSEMBLE}[$ens]->{V} += $v[1];

					$n++;

			   }

			}

		}

	}

	if ($n >= 2) {

		my(@sumsq) = (0,0);

		$dta{ENSEMBLE}[$ens]->{U} /= $n;

		$dta{ENSEMBLE}[$ens]->{V} /= $n;

		for ($i=0; $i<$n; $i++) {

			$sumsq[0] += ($dta{ENSEMBLE}[$ens]->{U}-$goodU[$i])**2;

			$sumsq[1] += ($dta{ENSEMBLE}[$ens]->{V}-$goodV[$i])**2;

		}

		$dta{ENSEMBLE}[$ens]->{U_ERR} = sqrt($sumsq[0])/($n-1);

		$dta{ENSEMBLE}[$ens]->{V_ERR} = sqrt($sumsq[1])/($n-1);

    } else {

		$dta{ENSEMBLE}[$ens]->{U} = undef;

		$dta{ENSEMBLE}[$ens]->{V} = undef;

    }    	

}

#----------------------------------------------------------------------

($x,$y) = (0,0);											# init

$dta{ENSEMBLE}[$firstgood]->{X} = $dta{ENSEMBLE}[$firstgood]->{X_ERR} = 0;

$dta{ENSEMBLE}[$firstgood]->{Y} = $dta{ENSEMBLE}[$firstgood]->{Y_ERR} = 0;

$prevgood = $firstgood;

for ($e=$firstgood+1; defined($opt_M)&&$e<=$lastgood; $e++) {

	#--------------------------------------------------

	# within profile: both $firstgood and $prevgood set

	#--------------------------------------------------

	ref_lr_uv($e,$dta{ENSEMBLE}[$e]->{DEPTH},$water_depth)	# instrument vel

		if (defined($dta{ENSEMBLE}[$e]->{W}));

	if (!defined($dta{ENSEMBLE}[$e]->{U})) {				# gap

		$uv_gap_time += $dta{ENSEMBLE}[$e]->{UNIX_TIME} -

				   		$dta{ENSEMBLE}[$e-1]->{UNIX_TIME};

		next;

	}

	my($dt) = $dta{ENSEMBLE}[$e]->{UNIX_TIME} -			# time step since

			  $dta{ENSEMBLE}[$prevgood]->{UNIX_TIME};		# ...last good ens

	#-----------------------------------

	# The current ensemble has valid u/v

	#-----------------------------------

	$x -= $dta{ENSEMBLE}[$prevgood]->{U} * $dt;			# integrate

	$xErr += ($dta{ENSEMBLE}[$prevgood]->{U_ERR} * $dt)**2;

	$dta{ENSEMBLE}[$e]->{X} = $x;

	$dta{ENSEMBLE}[$e]->{X_ERR} = sqrt($xErr);

	$y -= $dta{ENSEMBLE}[$prevgood]->{V} * $dt;

	$yErr += ($dta{ENSEMBLE}[$prevgood]->{V_ERR} * $dt)**2;

	$dta{ENSEMBLE}[$e]->{Y} = $y;

	$dta{ENSEMBLE}[$e]->{Y_ERR} = sqrt($yErr);

	$prevgood = $e;

}

unless (defined($dta{ENSEMBLE}[$lastgood]->{X})) {		# last is bad in u/v

	my($dt) = $dta{ENSEMBLE}[$lastgood]->{UNIX_TIME} -		# time step since

			  $dta{ENSEMBLE}[$prevgood]->{UNIX_TIME};		# ...last good ens

	$x -= $dta{ENSEMBLE}[$prevgood]->{U} * $dt;			# integrate

	$xErr += ($dta{ENSEMBLE}[$prevgood]->{U_ERR} * $dt)**2;

	$dta{ENSEMBLE}[$lastgood]->{X} = $x;

	$dta{ENSEMBLE}[$lastgood]->{X_ERR} = sqrt($xErr);

	$y -= $dta{ENSEMBLE}[$prevgood]->{V} * $dt;

	$yErr += ($dta{ENSEMBLE}[$prevgood]->{V_ERR} * $dt)**2;

	$dta{ENSEMBLE}[$lastgood]->{Y} = $y;

	$dta{ENSEMBLE}[$lastgood]->{Y_ERR} = sqrt($yErr);

}

$firstgood++ if ($firstgood == 0);							# centered diff

$lastgood-- if ($lastgood == $#{$dta{ENSEMBLE}});			# in step 6

#======================================================================

# Step 3: Calculate Uncertainties

#======================================================================

# Time series of W_ERR indicate that errors are very large near the

# surface and near the sea bed, perhaps because of reflections.

# A reasonable estimate for typical uncertainty is therefore the mode

# of the std errors.

my(@histUErr,@histVErr,@histWErr);

my($histRez) = 1e-4;

for ($e=$firstgood; $e<=$lastgood; $e++) {

	$histWErr[int($dta{ENSEMBLE}[$e]->{W_ERR}/$histRez+0.5)]++

		if defined($dta{ENSEMBLE}[$e]->{W_ERR});

	$histUErr[int($dta{ENSEMBLE}[$e]->{U_ERR}/$histRez+0.5)]++

		if defined($dta{ENSEMBLE}[$e]->{U_ERR});

	$histVErr[int($dta{ENSEMBLE}[$e]->{V_ERR}/$histRez+0.5)]++

		if defined($dta{ENSEMBLE}[$e]->{V_ERR});

}	

my($max) = 0; my($mode);

for (my($i)=0; $i<=$#histWErr; $i++) {

	next if ($histWErr[$i] < $max);

	$max = $histWErr[$i]; $mode = $i;

}

$wErr = $mode * $histRez if defined($mode);

$max = 0; $mode = undef;

for (my($i)=0; $i<=$#histUErr; $i++) {

	next if ($histUErr[$i] < $max);

	$max = $histUErr[$i]; $mode = $i;

}

$uErr = $mode * $histRez if defined($mode);

$max = 0; $mode = undef;

for (my($i)=0; $i<=$#histVErr; $i++) {

	next if ($histVErr[$i] < $max);

	$max = $histVErr[$i]; $mode = $i;

}

$vErr = $mode * $histRez if defined($mode);

#print(STDERR "u: mu = $meanU / sigma = $uErr\n");

#print(STDERR "v: mu = $meanV / sigma = $vErr\n");

#print(STDERR "w: mu = $meanW / sigma = $wErr\n");

if (defined($opt_M)) {									# displacement errors

	$x_err = $uErr * $uv_gap_time + $dta{ENSEMBLE}[$lastgood]->{X_ERR};

	$y_err = $vErr * $uv_gap_time + $dta{ENSEMBLE}[$lastgood]->{Y_ERR};

}

$z_err = $wErr * $w_gap_time + $dta{ENSEMBLE}[$lastgood]->{DEPTH_ERR};

#printf(STDERR "x_err = $dta{ENSEMBLE}[$lastgood]->{X_ERR} + %g\n",

#				$uErr * $uv_gap_time);

#printf(STDERR "y_err = $dta{ENSEMBLE}[$lastgood]->{Y_ERR} + %g\n",

#				$vErr * $uv_gap_time);

#printf(STDERR "z_err = $dta{ENSEMBLE}[$lastgood]->{DEPTH_ERR} + %g\n",

#				$wErr * $w_gap_time);

#======================================================================

# Step 4: Calculate Beam Range Stats

#======================================================================

my($min_good_bins) = 999;

my($worst_beam);

sub count_good_vels($)								# count good vels

{

	my($ens) = @_;

	my($good) = -1; my($this_worst_beam);

	if ($beamCoords) {

		for (my($i)=0; $i<$dta{N_BINS}; $i++) {

			for (my($b)=0; $b<4; $b++) {

				$good=$i,$this_worst_beam=$b,$nVels[$i][$b]++

					if defined($dta{ENSEMBLE}[$ens]->{VELOCITY}[$i][$b]);

			}

	    }