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

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

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

#                    (c) 2010 A.M. Thurnherr

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

# HISTORY:

#	Oct 20, 2010: - created

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

#	Oct 11, 2011: - moved defaults to [defaults.pl]

#	Oct 24, 2011: - disabled not-very-useful %BT-params

#	Apr 22, 2013: - replace output_bin_size by opt_o

#	Mar  4, 2014: - removed old unused code

#	Jan 26, 2016: - added %PARAMs

#   May 24, 2016: - calc_binDepths() -> binDepths()

#	May  1, 2018: - log-file cosmetics

# This code is derived from the one used in LADCPproc, with the following

# 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

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

# bin valid BT-referenced velocities

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

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

#			editflags 					for information

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

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) = 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

	return													# can happen when no MEDIAN_RESIDUAL_W is available

		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);

	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 inconsistent 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]});

	}

}

1;