function checkbtrk2(d,p);

% compare RDI to own bottom track

% 

if ~existf(p,'zbottom'), return , end

if ~isfinite(p.zbottom), return, end

  ii=find(abs(d.z+p.zbottom)<max(p.btrk_range) & ...

          abs(d.z+p.zbottom)>min(p.btrk_range));

  if existf(d,'bvel_rdi')

   bu_rdi=d.bvel_rdi(ii,1);

   bv_rdi=d.bvel_rdi(ii,2);

   bw_rdi=d.bvel_rdi(ii,3);

  else

   bu_rdi=d.bvel(ii,1)*nan;

   bv_rdi=d.bvel(ii,2)*nan;

   bw_rdi=d.bvel(ii,3)*nan;

  end

  if existf(d,'hbot_rdi')

   bh_rdi=d.hbot_rdi(ii);

  else

   bh_rdi=d.hbot(ii)*nan;

  end

  bu_own=d.bvel_own(ii,1);

  bv_own=d.bvel_own(ii,2);

  bw_own=d.bvel_own(ii,3);

  bh_own=d.hbot_own(ii);

 if 0

  rw=d.rw(d.izd,ii);

  ij=find((d.izm(d.izd,ii)+p.zbottom)<d.zd(1));

  rw(ij)=nan;

  if existf(d,'wctd') 

   w_c=d.wctd(ii)';

   disp(' use CTD pressure derived W')

  else

   w_c=medianan(rw,3)';

   disp(' use reference layer W')

  end

 end

  bu_used=d.bvel(ii,1);

  bv_used=d.bvel(ii,2);

  bw_used=d.bvel(ii,3);

  bh_used=d.hbot(ii);

  u_c=bu_used;

  v_c=bv_used;

  w_c=bw_used;

  w_c2=w_c-[0;diff(w_c)/2 ];

  blen=d.down.Cell_length/100;

% extract raw velocity data near bottom

ru=d.ru(d.izd,ii);

rv=d.rv(d.izd,ii);

rw=d.rw(d.izd,ii);

rtg=d.tg(d.izd,ii);

% correct velocities with solved U_ctd

rua=ru-repmat(u_c',[length(d.izd) 1]);

rva=rv-repmat(v_c',[length(d.izd) 1]);

rwa=rw-repmat(w_c',[length(d.izd) 1]);

% compute slope factor

ruan=abs(ru)./(abs(repmat(u_c',[length(d.izd) 1])));

ij=find(abs(u_c)<0.05);

ruan(:,ij)=nan;

rvan=abs(rv)./(abs(repmat(v_c',[length(d.izd) 1])));

ij=find(abs(v_c)<0.05);

rvan(:,ij)=nan;

rwan=abs(rw)./(abs(repmat(w_c',[length(d.izd) 1])));

ij=find(abs(w_c)<0.05);

rwan(:,ij)=nan;

bua_rdi=bu_rdi-u_c;

bva_rdi=bv_rdi-v_c;

% try to use w inbetween pings for real bottom track

bwa1_rdi=bw_rdi-w_c;

bwa2_rdi=bw_rdi-w_c2;

if stdnan(bwa1_rdi)>stdnan(bwa2_rdi)

 bwa_rdi=bwa2_rdi;

 disp(' use inbetween w-ref')

else

 bwa_rdi=bwa1_rdi;

end

bua_own=bu_own-u_c;

bva_own=bv_own-v_c;

bwa_own=bw_own-w_c;

bua_used=bu_used-u_c;

bva_used=bv_used-v_c;

bwa_used=bw_used-w_c;

% save bias and std of bottom track anomaly

p.btrk_u_bias=medianan(bua_used,6);

p.btrk_u_std=stdnan(bua_used);

p.btrk_v_bias=medianan(bva_used,6);

p.btrk_v_std=stdnan(bva_used);

p.btrk_w_bias=medianan(bwa_used,6);

p.btrk_w_std=stdnan(bwa_used);

disp(['CHECKBTRK: check bottom track against U_RDI solution '])

disp([' profiles within give acceptable range: ',int2str(length(ii))])

disp(['  U bias :',num3str(p.btrk_u_bias,6,3),' [m/s]  std: ',...

       num3str(p.btrk_u_std,5,3),' [m/s]'])

disp(['  V bias :',num3str(p.btrk_v_bias,6,3),' [m/s]  std: ',...

       num3str(p.btrk_v_std,5,3),' [m/s]'])

disp(['  W bias :',num3str(p.btrk_w_bias,6,3),' [m/s]  std: ',...

       num3str(p.btrk_w_std,5,3),' [m/s]'])

if abs(p.btrk_u_bias)>0.1

 warn=[' large U bottom track bias ',num2str(p.btrk_u_bias)];

 disp(warn)

 p.warnp(size(p.warnp,1)+1,1:length(warn))=warn;

end

if abs(p.btrk_v_bias)>0.1

 warn=[' large V bottom track bias ',num2str(p.btrk_v_bias)];

 disp(warn)

 p.warnp(size(p.warnp,1)+1,1:length(warn))=warn;

end

izm=d.izm(d.izd,ii);

% real binsize

dbin=medianan(medianan(diff(izm)));

% correct nominal depth with detected bottom depth

zcor=(-d.hbot(ii)+d.z(ii));

zcor_std=stdnan(zcor);

p.btrk_rough=zcor_std;

izm=izm-repmat(zcor,[length(d.izd) 1]);

% compute bias W slope

 dz=abs(diff(d.zd(1:2)));

 wbias=[];

 zbias=[];

 nbias=[];

 for i=1:6

  dzi=dz*i/2;

  ij=find(abs(izm+dzi)<(dz/4));

  nok=sum(isfinite(rwan(ij)));

  if nok>5

   wbias=[wbias, 1-medianan(rwan(ij))];

   zbias=[zbias, dzi];

   nbias=[nbias, nok];

  end

 end

 if exist('wbias')==1

  p.wbslope=polyfit(zbias,wbias,1);

 else

  wbias=nan;

  zbias=nan;

  p.wbslope=[nan nan];

 end

disp(['  W slope fact :',num3str(p.wbslope(1),6,4),' [1/m] lower W below bottom '])

% compute 'wave' action

p.btrk_wdiff=medianan(abs(diff(w_c)));

disp(['  W diff :',num3str(p.btrk_wdiff,6,4),' [m/s] ping to ping w difference '])

disp(['  H std :',num3str(zcor_std,6,1),' [m]  large means bottom is rough/sloped'])

p.btrk_tilt_mean=mean(d.tilt(ii));

p.btrk_tilt_std=std(d.tilt(ii));

disp(['  Tilt mean :',num3str(p.btrk_tilt_mean,3,1),' +/- ',...

           num3str(p.btrk_tilt_std,3,1),' [^o]  '])

% selcet bins used for own bottom track

iz=find(abs(izm+blen*p.btrk_below)<blen);

% predict velocity bias from geometry

bangle=d.down.Beam_angle;

sina=sin(bangle*pi/180);

cosa=cos(bangle*pi/180);

gamma=linspace(0,50,20);

sinab=sin(gamma*pi/180);

cosab=cos(gamma*pi/180);

% evaluate at three distances

mhbot=[150 100 50];

cm=['-g';'-b';'-r'];

% plot results

tx2=0.25;

figure(13)

clf

 subplot(221)

 plot(rua,izm,'.k')

 hold on

 plot(rua(iz),izm(iz),'.r')

 axis tight

 ax=axis;

 ax(1:2)=[-1 1]*0.8;

 ax(3)=-160;

 ax(4)=50;

 vh=floor(ax(1)*20)/20+0.0125 : 0.025: ceil(ax(2)*20)/20;

 plot(ax(1:2),[0 0],'-')

 plot([0 0]-meannan(u_c),ax(3:4),'k-','linewidth',1.5)

 plot([0 0]+p.btrk_u_bias,ax(3:4),'r-','linewidth',1.5)

 text(tx2,10,' Bottom')

 if sum(isfinite(bua_rdi))>0

  [y,x]=hist(bua_rdi,vh);

  y([1,end])=0;

  ys=sum(y);

  [x,y]=stairs(x,y);

  fill(x,y/max(y)*30-50,'-g')

  plot([0 0]+medianan(bua_rdi,6),ax(3:4),'-g')

  text(tx2,-40,['RDI n: ',int2str(ys)])

  text(0.1,-10,[' bias ',num3str(medianan(bua_rdi,6),6,3)],'color','g')

 end

 [y,x]=hist(bua_own,vh);

 y([1,end])=0;

 ys=sum(y);

 [x,y]=stairs(x,y);

 fill(x,y/max(y)*30-100,'-b')

 plot([0 0]+medianan(bua_own,6),ax(3:4),'-b')

 text(tx2,-90,[' own n: ',int2str(ys)])

 text(0.1,-60,[' bias ',num3str(medianan(bua_own,6),6,3)],'color','b')

 title([' U bot-tr mean U_{brt} : ',num3str(meannan(u_c),4,2),...

        ' [m/s] removed'])

 xlabel(' U [m/s]')

 ylabel('depth [m]')

 axis(ax)

 text(-0.7,-154,['Bottom roughness: ',int2str(p.btrk_rough),' [m]'])

subplot(222)

 ii=find(bh_used>=110);

 plot(ruan(:,ii),izm(:,ii),'.g')

 hold on

 ii=find(bh_used<=80);

 plot(ruan(:,ii),izm(:,ii),'.r')

 ii=find(bh_used>80 & bh_used<110);

 plot(ruan(:,ii),izm(:,ii),'.b')

 axis tight

 ax=axis;

 ax(1:2)=[0.0 2.0];

 ax(3)=-60;

 ax(4)=60;

 title([' U bottom track factor hbot: (g)>120 (r)<70 '])

 xlabel(' abs(U)/abs(U_{RDI}) ')

 ylabel('depth [m]')

 axis(ax)

 for i=-2:2

  plot(ax(1:2),dbin*i+[0 0],'-k')

 end

 plot([1 1],ax(3:4),'k-','linewidth',1.5)

 % plot model

 for i=1:length(mhbot)

  lbot=mhbot(i)./cosab;

  nbot=lbot*cosa-mhbot(i)-dbin/2;

  plot(sinab/sina,-nbot,cm(i,:))

 end

subplot(223)

 plot(rva,izm,'.k')

 hold on

 plot(rva(iz),izm(iz),'.r')

 axis tight

 ax=axis;

 ax(1:2)=[-1 1]*0.8;

 ax(3)=-160;

 ax(4)=50;

 plot(ax(1:2),[0 0],'-')

 plot([0 0]-meannan(v_c),ax(3:4),'k-','linewidth',1.5)

 plot([0 0]+p.btrk_v_bias,ax(3:4),'r-','linewidth',1.5)

 text(tx2,10,' Bottom')

 if sum(isfinite(bva_rdi))>0

  [y,x]=hist(bva_rdi,vh);

  y([1,end])=0;

  ys=sum(y);

  [x,y]=stairs(x,y);

  fill(x,y/max(y)*30-50,'-g')

  plot([0 0]+medianan(bva_rdi,6),ax(3:4),'-g')

  text(tx2,-40,[' RDI n: ',int2str(ys)])

  text(0.1,-10,[' bias ',num3str(medianan(bva_rdi,6),6,3)],'color','g')

 end

 [y,x]=hist(bva_own,vh);

 y([1,end])=0;

 ys=sum(y);

 [x,y]=stairs(x,y);

 fill(x,y/max(y)*30-100,'-b')

 plot([0 0]+medianan(bva_own,6),ax(3:4),'-b')

 text(tx2,-90,[' own n: ',int2str(ys)])

 text(0.1,-60,[' bias ',num3str(medianan(bva_own,6),6,3)],'color','b')

 title([' V bot-tr mean V_{brt} : ',num3str(meannan(v_c),4,2),...

        ' [m/s] removed'])

 xlabel(' V [m/s]')

 ylabel('depth [m]')

 text(-0.7,-154,['Tilt : ',num3str(p.btrk_tilt_mean,3,1),' +/- ',...

                 num3str(p.btrk_tilt_std,3,1),' [^o]'])

 axis(ax)

subplot(224)

 ii=find(bh_used>=110);

 plot(rvan(:,ii),izm(:,ii),'.g')

 hold on

 ii=find(bh_used<=80);

 plot(rvan(:,ii),izm(:,ii),'.r')

 ii=find(bh_used>80 & bh_used<110);

 plot(rvan(:,ii),izm(:,ii),'.b')

 axis tight

 ax=axis;

 ax(1:2)=[0.0 2.0];

 ax(3)=-60;

 ax(4)=60;

 title([' V bottom track factor hbot: (g)>120 (r)<70 '])

 xlabel(' abs(V)/abs(V_{RDI}) ')

 ylabel('depth [m]')

 axis(ax)

 for i=-2:2

  plot(ax(1:2),dbin*i+[0 0],'-k')

 end

 plot([1 1],ax(3:4),'k-','linewidth',1.5)

 % plot model

 for i=1:length(mhbot)

  lbot=mhbot(i)./cosab;

  nbot=lbot*cosa-mhbot(i)-dbin/2;

  plot(sinab/sina,-nbot,cm(i,:))

 end

streamer([p.name,' Figure 13']);

figure(14)

clf

tx2=0.05;

subplot(221)

 plot(rwa,izm,'.k')

 hold on

 plot(rwa(iz),izm(iz),'.r')

 axis tight

 ax=axis;

 ax(1:2)=[-1 1]*0.4;

 vh=floor(ax(1)*20)/20+0.005 : 0.01: ceil(ax(2)*20)/20;

 ax(3)=-160;

 ax(4)=50;

 plot(ax(1:2),[0 0],'-')

 plot([0 0],ax(3:4),'k-')

 plot([0 0]+p.btrk_w_bias,ax(3:4),'r-','linewidth',1.5)

 text(tx2,10,' Bottom')

 if sum(isfinite(bwa_rdi))>0

  [y,x]=hist(bwa_rdi,vh);

  y([1,end])=0;

  ys=sum(y);

  [x,y]=stairs(x,y);

  fill(x,y/max(y)*30-50,'-g')

  plot([0 0]+medianan(bwa_rdi,6),ax(3:4),'-g')

  text(tx2,-40,[' RDI n: ',int2str(ys)])

  text(0.1,-10,[' bias ',num3str(medianan(bva_rdi,6),6,3)],'color','g')

 end

 [y,x]=hist(bwa_own,vh);

 y([1,end])=0;

 ys=sum(y);

 [x,y]=stairs(x,y);

 fill(x,y/max(y)*30-100,'-b')

 plot([0 0]+medianan(bwa_own,6),ax(3:4),'-b')

 text(tx2,-90,[' own n: ',int2str(ys)])

 text(0.1,-60,[' bias ',num3str(medianan(bwa_own,6),6,3)],'color','b')

 title([' W bottom track [m/s] '])

 xlabel(' W [m/s]')

 ylabel('depth [m]')

 axis(ax)

tx2=0.65;

subplot(222)

 ii=find(bh_used>=110);

 plot(rwan(:,ii),izm(:,ii),'.g')

 hold on

 ii=find(bh_used<=80);

 plot(rwan(:,ii),izm(:,ii),'.r')

 ii=find(bh_used>80 & bh_used<110);

 plot(rwan(:,ii),izm(:,ii),'.b')

 axis tight

 ax=axis;

 ax(1:2)=[0.5 1.2];

 ax(3)=-60;

 ax(4)=60;

 title([' W bottom track factor '])

 xlabel(' abs(W)/abs(W_{ref}) ')

 ylabel('depth [m]')

 axis(ax)

 for i=-2:2

  plot(ax(1:2),dbin*i+[0 0],'-k')

 end

 plot([1 1],ax(3:4),'k-','linewidth',1.5)

 plot(1-wbias,-zbias,'pb')

 grid

 % plot model

 for i=1:length(mhbot)

  lbot=mhbot(i)./cosab;

  nbot=lbot*cosa-mhbot(i)-dbin/2;

  plot(cosab/cosa,-nbot,cm(i,:))

 end

 text(0.54,-50,[' bias slope ',num3str(p.wbslope(1),6,3),' [1/m]'])

 text(0.54,-58,[' offset  ',num3str(p.wbslope(2),6,3) ])

 text(0.54,50,[' beam angle  ',int2str(d.down.Beam_angle)])

 text(0.54,42,[' bin length  ',int2str(d.down.Cell_length/100),' [m]'])

 text(0.54,34,[' Pings/Ens  ',int2str(d.down.Pings_per_Ensemble)])

 text(0.54,26,[' Frequency  ',int2str(d.down.Frequency),' [kHz]'])

 text(0.54,10,[' Zbottom  ',int2str(p.zbottom),' [m]'])

subplot(223)

 ii=find(bh_used>=110);

 plot(rtg(:,ii),izm(:,ii),'.g')

 hold on

 ii=find(bh_used<=80);

 plot(rtg(:,ii),izm(:,ii),'.r')

 ii=find(bh_used>80 & bh_used<110);

 plot(rtg(:,ii),izm(:,ii),'.b')

 axis tight

 ax=axis;

 %ax(1:2)=[-1 1]*0.4;

 ax(3)=-60;

 ax(4)=60;

 for i=-2:2

  plot(ax(1:2),dbin*i+[0 0],'-k')

 end

 plot([0 0],ax(3:4),'k-')

 text(tx2,3,' Bottom')

 title([' Target Strength '])

 xlabel(' TG range corrected [dB]')

 ylabel('depth [m]')

 axis(ax)

  streamer([p.name,' Figure 14']);

  orient tall