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

#                    B O T T O M _ T R A C K I N G . P L 

#                    doc: Wed Oct 20 21:05:37 2010

#                    dlm: Fri Dec 31 14:21:14 2010

#                    (c) 2010 A.M. Thurnherr

#                    uE-Info: 32 30 NIL 0 0 72 2 2 4 NIL ofnI

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

# HISTORY:

#	Oct 20, 2010: - created

#	Dec 30, 2010: - adapted for use with LADCP_w

# This code is essentially identical to the one used in LADCPproc. Differences:

#	1) velocity editing is simpler: no wake editing, no PPI editing, no shear

#	   editing, no w outlier

#	2) median/mad calculated instead of mean/stddev

#	3) u,v not calculated

# Don't look for BT-referenced velocities if package is more than $BT_max_range

# above seabed. This parameter is frequency dependent and the current value is

# appropriate (if rather high) for 300kHz Workhorse intruments.

my($BT_max_range) = 300;

# The code only tries to bin BT-referenced velocities if a consistent bottom

# is available in all 4 beams. Ensembles where the range of bin numbers where

# the maximum echo is found is greater than $max_BIT_bin_range_diff are rejected.

# In addition to flukes this also rejects ensembles collected with large

# instrument tilts. The value of 3 is a first guess that has not been explored.

my($BT_max_bin_range_diff) = 3;

# If the difference between measured vertical velocity of the seabed (i.e.

# the package vertical velocity referenced by the seabed) and the vertical

# velocity of the CTD (from dp/dt) si greater than $BT_max_w_error the current

# ensemble is ignored and $nBTwFlag is increased. The value of

# 3cm/s is taken from listBT developed on A0304 cruise.

my($BT_max_w_error) = 0.03;

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

# bin valid BT-referenced velocities

#	input:	ensemble number, water depth (with uncertainty)

#	output:	@BTu,@BTv,@BTw				main result

#			editflags 					for information

#			@BTbtmu, @BTbtmv, @BTtilt 	stats to find reasons for quality differences

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

my($nBTfound,$nBTdepthFlag,$nBTvalidVelFlag,$nBTwFlag) = (0,0,0,0);

my(@BTu,@BTv,@BTw);

sub binBTprof($$$)

{

	my($ens,$wd,$sig_wd) = @_;

	my(@ea_max) = (0,0,0,0); my(@ea_max_bin) = (nan,nan,nan,nan);

	for (my($bin)=$LADCP_firstBin-1; $bin<=$LADCP_lastBin-1; $bin++) {

		$ea_max[0] = $LADCP{ENSEMBLE}[$ens]->{ECHO_AMPLITUDE}[$bin][0],

		$ea_max_bin[0] = $bin

			if ($LADCP{ENSEMBLE}[$ens]->{ECHO_AMPLITUDE}[$bin][0] > $ea_max[0]);

		$ea_max[1] = $LADCP{ENSEMBLE}[$ens]->{ECHO_AMPLITUDE}[$bin][1],

		$ea_max_bin[1] = $bin

			if ($LADCP{ENSEMBLE}[$ens]->{ECHO_AMPLITUDE}[$bin][1] > $ea_max[1]);

		$ea_max[2] = $LADCP{ENSEMBLE}[$ens]->{ECHO_AMPLITUDE}[$bin][2],

		$ea_max_bin[2] = $bin

			if ($LADCP{ENSEMBLE}[$ens]->{ECHO_AMPLITUDE}[$bin][2] > $ea_max[2]);

		$ea_max[3] = $LADCP{ENSEMBLE}[$ens]->{ECHO_AMPLITUDE}[$bin][3],

		$ea_max_bin[3] = $bin

			if ($LADCP{ENSEMBLE}[$ens]->{ECHO_AMPLITUDE}[$bin][3] > $ea_max[3]);

	}

	return													# disregard boundary maxima

		unless (min(@ea_max_bin) > $LADCP_firstBin-1) && 

			   (max(@ea_max_bin) < $LADCP_lastBin-1);

	return													# inconsistent range to seabed

		unless (max(@ea_max_bin)-min(@ea_max_bin) <= $BT_max_bin_range_diff);

	$nBTfound++;

	my($seafloor_bin) = round(avg(@ea_max_bin));

	my(@bd) = calc_binDepths($ens);

	$nBTdepthFlag++,return									# BT range inconsistent with water depth

		unless (abs($wd-$bd[$seafloor_bin]) < max($sig_wd,$LADCP{BIN_LENGTH}));

	# try vertical velocities at seabed bin plus one above and below

	# this does not really work because, often, only one of the bins has valid velocities

	my($w1) = $LADCP{ENSEMBLE}[$ens]->{W_UNEDITED}[$seafloor_bin-1];

	my($w2) = $LADCP{ENSEMBLE}[$ens]->{W_UNEDITED}[$seafloor_bin  ];

	my($w3) = $LADCP{ENSEMBLE}[$ens]->{W_UNEDITED}[$seafloor_bin+1];

	$w1 = 9e99 unless numberp($w1);							# invalid velocity sentinels

	$w2 = 9e99 unless numberp($w1);

	$w3 = 9e99 unless numberp($w1);

	my($seafloor_u,$seafloor_v,$seafloor_w);

	# determine which of the three trial bins is most consistent with reflr vertical velocities

	die("assertion failed") unless numberp($LADCP{ENSEMBLE}[$ens]->{REFLR_W});

	if (abs($LADCP{ENSEMBLE}[$ens]->{REFLR_W}-$w1) < abs($LADCP{ENSEMBLE}[$ens]->{REFLR_W}-$w2) &&

		abs($LADCP{ENSEMBLE}[$ens]->{REFLR_W}-$w1) < abs($LADCP{ENSEMBLE}[$ens]->{REFLR_W}-$w3)) {

			$seafloor_u = $LADCP{ENSEMBLE}[$ens]->{U_UNEDITED}[$seafloor_bin-1];

			$seafloor_v = $LADCP{ENSEMBLE}[$ens]->{V_UNEDITED}[$seafloor_bin-1];

			$seafloor_w = $LADCP{ENSEMBLE}[$ens]->{W_UNEDITED}[$seafloor_bin-1];

	} elsif (abs($LADCP{ENSEMBLE}[$ens]->{REFLR_W}-$w1) < abs($LADCP{ENSEMBLE}[$ens]->{REFLR_W}-$w2)) {

			$seafloor_u = $LADCP{ENSEMBLE}[$ens]->{U_UNEDITED}[$seafloor_bin+1];

			$seafloor_v = $LADCP{ENSEMBLE}[$ens]->{V_UNEDITED}[$seafloor_bin+1];

			$seafloor_w = $LADCP{ENSEMBLE}[$ens]->{W_UNEDITED}[$seafloor_bin+1];

	} else {

			$nBTvalidVelFlag++,return						# none of 3 trial bins has valid velocity

				if ($w2 == 9e99);

			$seafloor_u = $LADCP{ENSEMBLE}[$ens]->{U_UNEDITED}[$seafloor_bin];

			$seafloor_v = $LADCP{ENSEMBLE}[$ens]->{V_UNEDITED}[$seafloor_bin];

			$seafloor_w = $LADCP{ENSEMBLE}[$ens]->{W_UNEDITED}[$seafloor_bin];

	}

	$nBTwFlag++,return										# velocity error is too great

		if (abs($seafloor_w-$LADCP{ENSEMBLE}[$ens]->{REFLR_W}) > $BT_max_w_error);

	push(@BTbtmu,$seafloor_u);								# calc stats to try to find reasons for quality

	push(@BTbtmv,$seafloor_v);

	push(@BTbtmw,$seafloor_w);

	push(@BTtilt,$LADCP{ENSEMBLE}[$ens]->{TILT});

	for (my($bin)=$LADCP_firstBin-1; $bin<=$LADCP_lastBin-1; $bin++) {

		next unless defined($LADCP{ENSEMBLE}[$ens]->{W}[$bin]);

		my($gi) = int($bd[$bin]) / $opt_o;

		push(@{$BTw[$gi]},$LADCP{ENSEMBLE}[$ens]->{W}[$bin]-$seafloor_w);

	}

}

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

# calculate BT-referenced velocity profile

#	input:	start,end LADCP ensembles, water depth with uncertainty

#	output: %BT{MEDIAN_W,MAD_W,N_SAMP}

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

sub calc_BTprof($$$$)

{

	my($LADCP_start,$LADCP_end,$wd,$sig_wd) = @_;

	for (my($ens)=$LADCP_start; $ens<=$LADCP_end; $ens++) {

		next unless ($wd-$LADCP{ENSEMBLE}[$ens]->{CTD_DEPTH} < $BT_max_range);

		binBTprof($ens,$wd,$sig_wd);

	}

	progress("\t$nBTfound BT ensembles found\n");

	progress("\t$nBTdepthFlag flagged bad because of wrong bottom depth\n");

	progress("\t$nBTvalidVelFlag flagged bad because of no valid velocities\n");

	progress("\t$nBTwFlag flagged bad because of incorrect vertical velocity\n");

	for (my($gi)=0; $gi<@BTw; $gi++) {						# calc grid medians & mads

		$BT{N_SAMP}[$gi] = @{$BTw[$gi]};

		$BT{MEDIAN_W}[$gi] = median(@{$BTw[$gi]});

        $BT{MAD_W}[$gi] = mad2($BT{W}[$gi],@{$BTw[$gi]});

	}

	&antsAddParams('BT_rms_seafloor_u',round(rms(@BTbtmu),0.01),

				   'BT_rms_seafloor_v',round(rms(@BTbtmv),0.01),

				   'BT_rms_seafloor_w',round(rms(@BTbtmw),0.01),

				   'BT_avg_seafloor_u',round(avg(@BTbtmu),0.01),

				   'BT_avg_seafloor_v',round(avg(@BTbtmv),0.01),

				   'BT_avg_seafloor_w',round(avg(@BTbtmw),0.01),

				   'BT_rms_tilt',round(rms(@BTtilt),0.1));

}

1;