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

#                    R D I _ U T I L S . P L 

#                    doc: Wed Feb 12 10:21:32 2003

#                    (c) 2003 A.M. Thurnherr

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

# miscellaneous RDI-specific utilities

# History:

#	Feb 12, 2003: - created

#	Feb 14, 2003: - added check for short (bad) data files

#	Feb 26, 2004: - added Earth-coordinate support

#				  - added ensure_BT_RANGE()

#	Mar 17, 2004: - set bad BT ranges to undef in ensure_BT_RANGE

#				  - calc mean/stddev in ensure_BT_RANGE

#	Mar 20, 2004: - BUG: find_seabed() could bomb when not enough

#					bottom guesses passed the mode_width test

#	Mar 30, 2004: - added &soundSpeed()

#	Nov  8, 2005: - WATER_DEPTH => Z_BT

#	Dec  1, 2005: - renamed to RDI_Utils.pl

#				  - folded in mk_prof from [mkProfile]

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

#	Feb  1, 2008: - added comment

#	Feb 22, 2008: - added ssCorr()

#	Apr  9, 2008: - BUG: duplicate line of code (without effect) in find_seabed() 

#				  - BUG: seabed < max depth was possible

#	Jan     2010: - fiddled with seabed detection params (no conclusion)

#	May 23, 2010: - renamed Z to DEPTH

use strict;

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

# fake_BT_RANGE(dta ptr)

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

# During cruise NBP0204 it was found that one of Visbeck's RDIs consistently

# returns zero as the bottom-track range, even thought the BT velocities

# are good. This functions calculates the ranges if they are missing.

sub cBTR($$$)

{

	my($d,$e,$b) = @_;

	my($maxamp) = -9e99;

	my($maxi);

	for (my($i)=0; $i<$d->{N_BINS}; $i++) {

		next unless ($d->{ENSEMBLE}[$e]->{ECHO_AMPLITUDE}[$i][$b] > $maxamp);

		$maxamp = $d->{ENSEMBLE}[$e]->{ECHO_AMPLITUDE}[$i][$b];

		$maxi = $i;

	}

	$d->{ENSEMBLE}[$e]->{BT_RANGE}[$b] =

		$d->{DISTANCE_TO_BIN1_CENTER} + $maxi * $d->{BIN_LENGTH};

}

sub ensure_BT_RANGE($)

{

	my($d) = @_;

	for (my($e)=0; $e<=$#{$d->{ENSEMBLE}}; $e++) {

		my($sum) = my($n) = 0;

		if (defined($d->{ENSEMBLE}[$e]->{BT_VELOCITY}[0])) {

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

				cBTR($d,$e,$b)

					unless defined($d->{ENSEMBLE}[$e]->{BT_RANGE}[$b]);

				$sum += $d->{ENSEMBLE}[$e]->{BT_RANGE}[$b]; $n++;

			}

		} else {

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

				$d->{ENSEMBLE}[$e]->{BT_RANGE}[$b] = undef;

			}

		}

		$d->{ENSEMBLE}[$e]->{BT_MEAN_RANGE} = $sum/$n if ($n == 4);

	}

}

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

# (seabed depth, stddev) = find_seabed(dta ptr, btm ensno, coord flag)

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

# NOTE FOR YOYOS:

#	- this routine only detects the BT around the depeest depth!

#	- this is on purpose, because it is used for [listBT]

# This is a PAIN:

# 	if the instrument is too close to the bottom, the BT_RANGE

#	readings are all out; the only solution is to have a sufficiently

#	large search width (around the max(depth) ensemble) so that

#	a part of the up (oops, I forgot to finish this comment one year

#	ago during A0304 and now I don't understand it any more :-)

my($search_width) = 200;	# # of ensembles around bottom to search

my($mode_width) = 10;		# max range of bottom around mode

my($min_dist) = 20;			# min dist to seabed for good data

my($z_offset) = 10000;		# shift z to ensure +ve array indices

sub find_seabed($$$)

{

	my($d,$be,$beamCoords) = @_;

	my($i,$dd,$sd,$nd);

	my(@guesses);

	return undef unless ($be-$search_width >= 0 &&

						 $be+$search_width <= $#{$d->{ENSEMBLE}});

	for ($i=$be-$search_width; $i<=$be+$search_width; $i++) {

		next unless (defined($d->{ENSEMBLE}[$i]->{DEPTH}) &&

					 defined($d->{ENSEMBLE}[$i]->{BT_RANGE}[0]) &&

					 defined($d->{ENSEMBLE}[$i]->{BT_RANGE}[1]) &&

					 defined($d->{ENSEMBLE}[$i]->{BT_RANGE}[2]) &&

					 defined($d->{ENSEMBLE}[$i]->{BT_RANGE}[3]));

		my(@BT) = $beamCoords

				? velInstrumentToEarth($d,$i,

					velBeamToInstrument($d,

						@{$d->{ENSEMBLE}[$i]->{BT_VELOCITY}}))

				: velApplyHdgBias($d,$i,@{$d->{ENSEMBLE}[$i]->{BT_VELOCITY}});

		next unless (abs($BT[3]) < 0.05);

		$d->{ENSEMBLE}[$i]->{DEPTH_BT} =

			 $d->{ENSEMBLE}[$i]->{BT_RANGE}[0]/4 +

			 $d->{ENSEMBLE}[$i]->{BT_RANGE}[1]/4 +

 			 $d->{ENSEMBLE}[$i]->{BT_RANGE}[2]/4 +

			 $d->{ENSEMBLE}[$i]->{BT_RANGE}[3]/4;

		next unless ($d->{ENSEMBLE}[$i]->{DEPTH_BT} >= $min_dist);

		$d->{ENSEMBLE}[$i]->{DEPTH_BT} *= -1

			if ($d->{ENSEMBLE}[$i]->{XDUCER_FACING_UP});

		$d->{ENSEMBLE}[$i]->{DEPTH_BT} += $d->{ENSEMBLE}[$i]->{DEPTH};

		if ($d->{ENSEMBLE}[$i]->{DEPTH_BT} > $d->{ENSEMBLE}[$be]->{DEPTH}) {

			$guesses[int($d->{ENSEMBLE}[$i]->{DEPTH_BT})+$z_offset]++;

			$nd++;

		} else {

			undef($d->{ENSEMBLE}[$i]->{DEPTH_BT});

		}

	}

	return undef unless ($nd>5);

	my($mode,$nmax);

	for ($i=0; $i<=$#guesses; $i++) {			# find mode

		$nmax=$guesses[$i],$mode=$i-$z_offset

			if ($guesses[$i] > $nmax);

	}

	$nd = 0;

	for ($i=$be-$search_width; $i<=$be+$search_width; $i++) {

		next unless defined($d->{ENSEMBLE}[$i]->{DEPTH_BT});

		if (abs($d->{ENSEMBLE}[$i]->{DEPTH_BT}-$mode) <= $mode_width) {

			$dd += $d->{ENSEMBLE}[$i]->{DEPTH_BT};

			$nd++;

		} else {

			$d->{ENSEMBLE}[$i]->{DEPTH_BT} = undef;

		}

	}

	return undef unless ($nd >= 2);

	$dd /= $nd;

	for ($i=$be-$search_width; $i<=$be+$search_width; $i++) {

		next unless defined($d->{ENSEMBLE}[$i]->{DEPTH_BT});

		$sd += ($d->{ENSEMBLE}[$i]->{DEPTH_BT}-$dd)**2;

	}

	return ($dd, sqrt($sd/($nd-1)));

}

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

# c = soundSpeed($salin,$temp,$depth)

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

# Taken from the RDI BroadBand primer manual. The reference given there

# is Urick (1983).

sub soundSpeed($$$)

{

	my($salin,$temp,$depth) = @_;

	die("ERROR: soundSpeed($salin,$temp,$depth): non-numeric parameter\n")

		unless numberp($salin) && numberp($temp) && numberp($depth);

	return 1449.2 + 4.6*$temp -0.055*$temp**2  + 0.00029*$temp**3 +

				(1.34 - 0.01*$temp) * ($salin - 35) + 0.016*$depth;

}

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

# fac = ssCorr($eRef,$salin,$temp,$depth)

#	$eRef :	reference to current ensemble

#	$salin: * -> use instrument salinity

#	$temp : * -> use instrument temperature

#	$depth: * -> use instrument PRESSURE(!)

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

{ my($warned);

	sub ssCorr($$$$)

	{

		my($eRef,$S,$T,$D) = @_;

		$S = $eRef->{SALINITY} if ($S eq '*');

		$T = $eRef->{TEMPERATURE} if ($T eq '*');

		if ($D eq '*') {

			print(STDERR "WARNING: soundspeed correction using instrument pressure instead of depth!\n")

				unless ($warned);

			$warned = 1;

			$D = $eRef->{PRESSURE};

		}

		return soundSpeed($S,$T,$D) / $eRef->{SPEED_OF_SOUND};

	}

}

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

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

#	mk_prof($dta,$check,$filter,$lr_b0,$lr_b1,$min_corr,$max_e,$max_gap);

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

sub ref_lr_w($$$$$$)								# calc ref-level vert vels

{

	my($dta,$ens,$rl_b0,$rl_b1,$min_corr,$max_e) = @_;

	my($i,@n,@bn,@v,@vel,@bv,@w);

	for ($i=$rl_b0; $i<=$rl_b1; $i++) {

		undef($dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][0])

			if ($dta->{ENSEMBLE}[$ens]->{CORRELATION}[$i][0] < $min_corr);

		undef($dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][1])

			if ($dta->{ENSEMBLE}[$ens]->{CORRELATION}[$i][1] < $min_corr);

		undef($dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][2])

			if ($dta->{ENSEMBLE}[$ens]->{CORRELATION}[$i][2] < $min_corr);

		undef($dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][3])

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

		if ($dta->{BEAM_COORDINATES}) {

			undef($dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][0])

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

			undef($dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][1])

				if ($dta->{ENSEMBLE}[$ens]->{PERCENT_GOOD}[$i][1] < 100);

			undef($dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][2])

				if ($dta->{ENSEMBLE}[$ens]->{PERCENT_GOOD}[$i][2] < 100);

			undef($dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][3])

	            if ($dta->{ENSEMBLE}[$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 = @{$dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i]};

			# NB: no need to apply heading bias, as long as we only use w!

		}

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

		if (defined($v[2])) {							# valid w

			$vel[2] += $v[2]; $n[2]++;

			$vel[3] += $v[3], $n[3]++ if defined($v[3]);

			push(@w,$v[2]); 							# for stderr test

		}

		if ($dta->{BEAM_COORDINATES}) {

			$bv[0] += $dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][0], $bn[0]++

				if defined($dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][0]);

			$bv[1] += $dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][1], $bn[1]++

				if defined($dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][1]);

			$bv[2] += $dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][2], $bn[2]++

				if defined($dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][2]);

			$bv[3] += $dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][3], $bn[3]++

	            if defined($dta->{ENSEMBLE}[$ens]->{VELOCITY}[$i][3]);

	    }

	}

	my($w) = $n[2] ? $vel[2]/$n[2] : undef;				# w uncertainty

	my($sumsq) = 0;

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

		$sumsq += ($w-$w[$i])**2;

	}

	my($stderr) = $n[2]>=2 ? sqrt($sumsq)/($n[2]-1) : undef;

#	The following stderr test introduces a huge gap near the bottom of

#	the profiles. Without it, they seem more reasonable.

#	next if ($stderr > 0.05);

	if (defined($w)) {									# valid w

		$dta->{ENSEMBLE}[$ens]->{W} = $w;

		$dta->{ENSEMBLE}[$ens]->{W_ERR} = $stderr;

	}

	if ($dta->{BEAM_COORDINATES}) {

		$dta->{ENSEMBLE}[$ens]->{V1} = $bn[0]>=2 ? $bv[0]/$bn[0] : undef;

		$dta->{ENSEMBLE}[$ens]->{V2} = $bn[1]>=2 ? $bv[1]/$bn[1] : undef;

		$dta->{ENSEMBLE}[$ens]->{V3} = $bn[2]>=2 ? $bv[2]/$bn[2] : undef;

	    $dta->{ENSEMBLE}[$ens]->{V4} = $bn[3]>=2 ? $bv[3]/$bn[3] : undef;

	}

}

sub mk_prof($$$$$$$$)										# make profile

{

	my($dta,$check,$filter,$lr_b0,$lr_b1,$min_corr,$max_e,$max_gap) = @_;

	my($firstgood,$lastgood,$atbottom,$w_gap_time,$zErr,$maxz);

	for (my($z)=0,my($e)=0; $e<=$#{$dta->{ENSEMBLE}}; $e++) {

		checkEnsemble($dta,$e) if ($check);

		filterEnsemble($dta,$e)

			if (defined($filter) &&

				$dta->{ENSEMBLE}[$e]->{PERCENT_GOOD}[0][0] > 0);

		ref_lr_w($dta,$e,$lr_b0,$lr_b1,$min_corr,$max_e);	# ref. layer w

		if (defined($firstgood)) {

			$dta->{ENSEMBLE}[$e]->{ELAPSED_TIME} =			# time since start

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

				$dta->{ENSEMBLE}[$firstgood]->{UNIX_TIME};

		} else {

			if (defined($dta->{ENSEMBLE}[$e]->{W})) {		# start of prof.

				$firstgood = $lastgood = $e;		    

				$dta->{ENSEMBLE}[$e]->{ELAPSED_TIME} = 0;

				$dta->{ENSEMBLE}[$e]->{DEPTH} = $dta->{ENSEMBLE}[$e]->{DEPTH_ERR} = 0;

			}

			next;

		}

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

		# within profile: both $firstgood and $lastgood set

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

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

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

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

			next;

		}

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

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

		if ($dt > $max_gap) {

			printf(STDERR "WARNING: %d-s gap too long, profile restarted at ensemble $e\n",$dt);

			$firstgood = $lastgood = $e;

			$dta->{ENSEMBLE}[$e]->{ELAPSED_TIME} = 0;

			$z = $zErr = $maxz = 0;

			$dta->{ENSEMBLE}[$e]->{DEPTH} = $dta->{ENSEMBLE}[$e]->{DEPTH_ERR} = 0;

			$w_gap_time = 0;

			next;

		}

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

		# The current ensemble has a valid w

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

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

		$dta->{ENSEMBLE}[$e]->{DEPTH_ERR} = sqrt($zErr);

		$atbottom = $e, $maxz = $z if ($z > $maxz); 

		$lastgood = $e;

	}

	filterEnsembleStats() if defined($filter);

	return ($firstgood,$lastgood,$atbottom,$w_gap_time,$zErr,$maxz);

}

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

# (true|false) = numberp(var)

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

sub numberp(@)

{ return  $_[0] =~ /^([+-]?)(?=\d|\.\d)\d*(\.\d*)?([Ee]([+-]?\d+))?$/; }

1;