Supplementary Software

Table Of Contents

Chart Conversion Manual

Table Of Contents

imgkap and the kap file

To convert a chart picture to a BSB chart, libbsb was for a long time the only choice.
With the arrival of "imgkap", there is an alternative with updated features.
Read more about imgkap here: www.dacust.com/inlandwaters/imgkap/
 

Picture to Chart, some details


For both tiff2bsb(libbsb) and imgkap there must be a user supplied "header" file containing information and Geo-referencing of the chart picture. This file can be produced in different ways. From simple handcrafting, to a method described on the page "Conversion Using Linux", which actually applies to windows as well in many parts.

To see a real header, just open a chart file (whatever.kap) in a text-editor.
The first part of the text in the beginning us user supplied, then comes a text part created by libbsb or imgkap an then the binary part.
Whatever method is used for conversion it is important to understand the header.
Here is a commented header file originating from the NGA project, that describes the essential items in a basic version.

VER/2.0 [0]
BSB/NA= [1]
    NU=[2],RA=[3],[4],DU=72
KNP/SC=[5],GD=[6],PR=[7]
    PP=[8],PI=UNKNOWN,SP=UNKNOWN,SK=[8a],TA=[8b]
    UN=[9],SD=[10],DX=000,DY=000[11]
CED/SE=[12],RE=[13],ED=[14]
OST/1
REF/1,[16]
REF/2,
REF/3,
REF/4,
PLY/1,[17]
PLY/2,
PLY/3,
PLY/4,
DTM/0.00,0.00 [18]
CPH/0.0 [19]



 
0. The BSB version used
1. *Name of chart from the chart. Warning do not use commas ",".
2. *Chart number. Plan A on 23456 should be named 23456_A
3.  Size of picture Pixel x coordinate
4.  Size of picture Pixel y coordinate
5. *Scale of the chart from the chart.
6. *Geodetic datum, for example WGS84, from the chart. I not defined on the chart write "UNKNOWN" No guesswork, it is either stated, or said to be a local datum, that cannot be related to WGS84. Charts released earlier than 1990 (?) and conforming to
World Geodetic System should be WGS72, unless stated otherwise. The difference between WGS 84 and WGS 72 is minor.
7. *Projection, almost always MERCATOR, a few charts are TRANSVERSE MERCATOR. We should not bother with other projections, GNOMONIC small scale great circle charts etc. If we come across large scale plans with GNOMONIC projection this should be used, say
 1:50,000 or larger. High latitude "Lambert Conformal Conic Projection" should be skipped, for now. OpenCPN only handles Mercator and  Transversal Mercator. I don't think th Polyconic charts.
8. *For Mercator charts this is the latitude where the scale is valid. If available on the chart, use that value.
If it is not available on the chart use the average value of the latitude of the upper and lower edge, to the nearest 1/10 of a degree.
For Transverse Mercator charts use the average _longitude_  of the eastern and western edge.
Treat a possible large scale gnomonic as a Mercator chart.
8a. SK is the skew angle of charts that are not "North Up". For North Up the value is 0.0
From OpenCPN 3.3.1117 skewed charts without this parameter set, are handled internally, and showed correctly. This is only to handled commercially issued charts that are not correctly coded.
8b.TA is he text angle, more or less always 90.0
9. Unit for soundings from the chart, mostly METERS
10. Datum for soundings from the chart, for ex MLWS, LAT
11. x and y resolution, meters per pixel. Not necessary for us to compute. OpenCPN andles this.
12. Chart edition date copied from the chart,inf in SW corner, except, there must be _no_ commas.
13. Our release edition.
14. Our release date.
16. Geo-referencing, standard case - simple 4 corner chart, use the 4 corners, starting in the SW corner proceeding clockwise.
Format: x pix,y pix, lat, long. Lat & long i decimal degrees, to 8 decimals, where N lat and E long are positive.
One reason to use all 4 corners is to catch  skewed and warped charts, and calculate SK (8a), also to calculate a rotating angle for charts that are not properly aligned.
17. Standard case, just copy the lat & long from the REFs.
18. Corrections in seconds of arc to bring the chart to WGS84. This is generally given on the chart(if they exist), in a format where the corrections are in minutes of arc for plotting a WGS84 position on the chart. This correction must be transformed to seconds of arc and the signs reversed.(we are doing the reverse to the case stated on the charts). These values are sometimes difficult to find on the chart.
19. If a chart  spans the 180th meridian = > CPH/180.0, else => CPH/0.0. So CPH/ is 0.0 for most charts. Note that OpenCPN handles transiting the 180:th meridian while a few other plotters don't.

**IFM** is not used as tif2bsb and imgkap calculates this value and ads it to the header on the final kap, together with other values such as RGB. Any manually entered values will be overwritten.

One great advantage with imgkap, compared to libbsb, is that generally the original format for the chart picture can be used directly.
To calibrate a chart can be as simple as composing the headerfile , a text file with the extension ".txt". Often the Lat&Long of the SW and NE corners are printed on the charts.
Use, for example GIMP, to find the pixelcoordinates for each corner.

For example, to the chart picture BA1121.jpg we write the header file  BA1121.txt.
To create the chart file with the extension ".kap", issue the command:

imgkap BA1121.jpg BA1121.txt BA1121.kap

The BSB/KAP file format.

Tim Thornton from the TeamSurv project has contributed an extended documentation of the bsb/kap file format headers.


There is a .BSB file for the chart (not required by OpenCPN and many others), and a .KAP file for each panel within the chart (and an additional optional file for updates to charts, which we won’t use). A header file is required. Create this in the tile folder with file name chartname.bsb.txt and chartname.kap.txt. This has the following formats. In all cases, date is in the format mm/dd/yyyy. Data fields must not have commas in them where there are sub fields, and probably not /. In the NA fields (and possibly others) /A indicates a new line. Subfields can be separated with a “,” or a new line.
Note that the origin for pixels is the top left (NW) corner of the chart, whereas for positions it is the usual SW corner.
Tests in OpenCPN have produced a minimum data set requirement for the KAP files. Fields that are required for chart display or for operational reasons have been highlighted in italics in the description. In addition, Raytech requires the BSB file to be present.
BSB Header

! An example BSB text header
VER/3.0
CRR/2013, TeamSurv. All rights reserved.
CHT/NA=Australia 3000000, NU=123
CHF/Coastal
CED/SE=70,RE=01,ED=07/25/2012
NTM/NE=70.00,ND=07/25/2012, BF = on, BD=07/25/2012
CHK/1,123
ORG/TeamSurv
MFR/TeamSurv
CGD/5
RGN/4,6
K01/NA= Australia 3000000
NU=123
TY=Base
FN=123_1.KAP
N000005580027/RT=N,KN=12221_1,CA=CHART,DE=TIDE BOX,P1=3020,8412
P2=3020,8771,P3=4114,8771,P4=4114,8412
N000005580041/RT=L,KN=12221_1,LK=N000005580027,DE=TIDE BOX,
P1=8527, 707
The text header is terminated with a <Control-Z><NUL> sequence (ASCII characters 26 and 0).
  • ! - Comment line
  • VER - Version number of BSB format – we will use 3.0
  • CRR Copyright message. Free text
  • CHT – General parameters
    • NA - Chart name given to the BSB chart (can represent more than one .KAP)
    • NU - Chart number.
  • CHF Chart format (e.g. Overview, General, Coastal, Approach, River, Harbour or Berthing)
  • CED – Chart edition parameters - optional
    • SE - Source edition / number of paper chart
    • RE - Raster edition / number
    • ED - Chart edition date/number
  • NTM – Notices to mariners - optional
    • NE - NTM edition number
    • ND - NTM date
    • BF - Base flag on or off (I guess this allows a base edition of the chart to be specified?)
    • BD - Base date
  • CHK – number of KAPs; KAP number(s). Note sure of format for > 1 KAP. Not sure if the separator should be , or ;
  • CGD - ? coast guard district – optional or can be unknown
  • RGN - ? - optional
  • ORG – Producing agency identifier – TeamSurv for us
  • MFR – Manufacturer of the RNC chart – TeamSurv for us
  • Knn – Records 1 – n for each KAP file
    • NA - Chart name given to the pane
    • NU - Pane number e.g. 123_A
    • TY - Type. Base for the base chart, Inset for a plan contained within the base chart, or extension for a plan outside of the base area
    • FN – KAP file name e.g. 123_1.kap
  • Naa – List of text boxes and hot spot links on the chart
    • RT – N for text box, L for hot spot link
    • KN - ?
    • CA – Category e.g. Chart, Caution, General etc
    • DE – Type e.g. Tide box, note etc
    • LK – Links this hot spot to the specified text box
    • P1, P2, P3, P4 – Hot spot location (just P1) or text box boundaries as 4 point polygon in x, y pixels
KAP Header

! An example KAP text header
VER/3.0
CRR/2013, TeamSurv. All rights reserved.
BSB/NA=Australia 3000000
NU=,RA=625,480,DU=50
KNP/SC=3000000,GD=,PR=LAMBERT CONFORMAL CONIC,PP=145.0
PI=0.0,SP=Unknown,0,SK=0.0
UN=METRES,SD=,DX=6000.0,DY=6000.0
KNQ/EC=RF,GD=NARC,VC=UNKNOWN,SC=MLLW,PC=MC,P1=UNKNOWN, P2=37.083
P3=NOT_APPLICABLE,P4=NOT_APPLICABLE,GC=NOT_APPLICA BLE,RM=POLYNOMIAL
CED/SE=70,RE=01,ED=07/25/2012
NTM/NE=70.00,ND=07/25/2012, BF = on, BD=07/25/2012
OST/1
IFM/3
RGB/1,199,231,252
RGB/2,174,234,84
RGB/3,255,254,206
RGB/4,226,65,6
CPH/0.0000000000
WPX/2,863264.4957,11420.23114,-85.46756208,1.913941167,-0.4081181078
0.7362163163
WPY/2,390032.0953,69.56409751,-6745.589267,0.4669253601,0.0367153316
-96.0547565
PWX/2,-76.48368342,8.999135076e-005,5.758392982e-009,-1.392859319e-012
-2.377189159e-013,-3.432372134e-013
PWY/2,37.44988807,-3.111799225e-009,-7.171936009e-005,2.694372983e-013
-1.725045227e-014,-3.594145418e-011
REF/1,374,8790,36.8166861111,-76.4500000000
REF/2,374,695,37.4000111111,-76.4500000000
REF/3,4505,695,37.4000111111,-76.0783222222
ERR/1,0.0395099814,0.1453734568,0.0000106128,0.0000035 393
ERR/2,0.2568631181,0.1909729033,0.0000135084,0.0000230 797
ERR/3,0.2741345061,0.0861261497,0.0000060346,0.0000246 567
PLY/1,36.8166666667,-76.4500000000
PLY/2,37.4000000000,-76.4500000000
PLY/3,37.4000000000,-76.0783333333
PLY/4,37.4083333333,-76.0783333333
DTM/0.0,0.0
The text header is terminated with a <Control-Z><NUL> sequence (ASCII characters 26 and 0).
Note that where the meaning of a field is the same as in the .BSB file above, it is not repeated here.
  • VER - Version number of BSB format – we will use 3.0
  • BSB (or NOS for older GEO/NOS or GEO/NO1 files) – General parameters
    • NA - Pane name
    • NU - Pane number. If chart is 123 and contains a plan A, the plan should be numbered 123_A
    • RA - width, height - width and height of raster image data in pixels
    • DU - Drawing Units in pixels/inch (same as DPI resolution) e.g. 50, 150, 175, 254, 300
  • KNP – Detailed chart parameters
    • SC - Scale e.g. 25000 means 1:25000
    • GD - Geodetic Datum e.g. WGS84 for us
    • PR - Projection e.g. MERCATOR for us. Other known values are TRANSVERSE MERCATOR or LAMBERT CONFORMAL CONIC or POLYCONIC. This must be one of those listed, as the value determines how PP etc. are interpreted. Only MERCATOR and TRANSVERSE MERCATOR are supported by OpenCPN.
    • PP – Projection parameter. For Mercator charts this is where the scale is valid, i.e. +lat_ts – use average latitude of the chart. For transverse Mercator it is the +lon_0 value.
    • PI – Projection interval ? e.g. 0.0, 0.033333, 0.083333, 2.0
    • SP -? – Unknown is valid
    • SK - Skew angle e.g. 0.0 for us. Angle of rotation of the chart
    • TA - text angle e.g. 90 for us
    • UNDepth units (for depths and heights) e.g. METRES, FATHOMS, FEET
    • SD - Sounding Datum e.g. MEAN LOWER LOW WATER, HHWLT or normally LAT
    • DX – X resolution, distance (meters) covered by one pixel in X direction. OpenCPN ignores this and DY
    • DY – Y resolution, distance covered by one pixel in Y direction
  • CED – Chart edition parameters (see BSB section)
  • NTM – Chart edition parameters (see BSB section)
  • OST - Offset STrip image lines (number of image rows per entry in the index table) e.g. 1. Generated by imgkap.
  • IFM - Depth of the colormap (bits per pixel). BSB supports 1 through 7 (2 through 127 max colors). Or compression type? Generated by imgkap.
  • RGB – Default colour palette - entries in the raster colormap of the form index,red,green,blue (index 0 is not used in BSB). Generated by imgkap.
  • DAY – Optional day colour palette
  • DSK – Optional dusk colour palette
  • NGT – Optional night colour palette
  • NGR – Optional night red colour palette
  • GRY – Optional grey scale palette
  • PRC – Optional palette
  • PRG – Optional grey palette
  • REF – Reference point record, gives point n, then position x, y in pixels, then in longitude, latitude - optional
  • CPH – Phase shift value - optional
  • WPX – Polynomial longitude to x - optional. The Polynomials is an alternative to REF points for georeferencing. OpenCPN uses these polynomials if they are available. The existence of polynomials is a condition for using noaa:s chart reprojection tool.
  • PWX – Polynomial x to longitude - optional
  • WPY – Polynomial latitude to y - optional
  • PWY – Polynomial y to latitude - optional
  • ERR – Error record –These should be present if polynomials are used. These ERR rows report the error at the REF points due to the usage of polynomials.
  • PLY - Border polygon record – coordinates of the panel within the raster image, given in chart datum lat/long. Any shape polygon
  • DTM – Datum shift parameters - Datum's northing and easting in floating point seconds to go between chart datum and WGS84 (omitted or 0,0 for WGS84 charts)
  • KNQ – Additional parameters - Optional
    • P1=?,
    • P2 - the same as KNP PP for Mercator and Transverse Mercator projection.
    • P3= scale factor for Transverse Mercator; 1st standard parallel for lambert conic
    • P4= 0 for Transverse Mercator; 2nd standard parallel for lambert conic
    • P5= Central meridian for Transverse Mercator and lambert conic
    • P6= origin of latitude for Transverse Mercator and lambert conic
    • P7 = +x_0 for Transverse Mercator and lambert conic
    • P8 = +y_0 for Transverse Mercator and lambert conic
    • EC=?
    • GD=?
    • VC= ?
    • SC=?
    • PC=?. Set to TC for Transverse Mercator.

libBSB

LibBSB is an older alternative to imgkap, for converting chart pictures to usable BSB type charts.

Full documentation and source code is available at libbsb.sourceforge.net.

Only binary packages for Debian based Linux distros and Windows are available for download here.  There may be packages available for alternative operating systems elsewhere.

libbsb-tools_0.0.7_i386.deb

libbsb-tools_0.0.7_amd64.deb

libbsb-0.0.7-win32.zip

 

 

Conversion Using Linux

How to convert your chart images to a format that OpenCPN will read using Linux

Do you have a bunch of scanned charts of your area, in graphical format (jpg, tiff, etc.) and OpenCPN won't read them?
Here's how you can – with a bit of work, sure, but worth the effort – convert them into usable electronic charts.

The tools:

  1. ImageMagick: http://www.imagemagick.org/ (Binary releases are available for a few distributions, for Ubuntu just get it with the package manager, it's in the repositories.)
  2. Libbsb: http://libbsb.sourceforge.net (You will need some version of libtiff-dev and libpng-dev installed to build it. A .deb package that worked fine for me can be found here.
  3. mc2bsbh: you can get it here.
    1. Get the c++ source file, and from its directory, type:
    2. g++ -Wall -s -O2 mc2bsbh.cpp -o mc2bsbh
    3. It compiled without any problem on my (very standard) Karmic. I personally put it in /usr/local/bin, which I own as user, so it's in the PATH and can be called from anywhere, if you leave it in the working directory, use ./mc2bsbh
  4. MapCal: part of the free navigation package SeaClear .
    1. Note: I had some problems running it with Wine (saving the calibration) but I can't reproduce the error and now it works fine. One suggestion is, make the directory you're going to write the calibration in world-writable before running MapCal.
  5. The pcx2tif script (optional) , found here.  This is a great little shell script by "taifun" used to convert old Maptech-style formats of tiled charts. If you find your chart is made of little bits instead of a whole file, this will stitch them all together in TIFF format.
    1. Instructions for use are in the tarball.

Once we have the tools all set up, we can get to work. The process in in five steps:

  1. Convert a chart image to tiff with imagemagick.
  2. Convert it again to png with the same (you'll need both files).
  3. Load the png version of the chart in Mapcal and calibrate it.
  4. Generate the chart header with mc2bsbh, and make the .kap version of the chart, with libbsb.
  5. Copy the resulting .kap into opencpn's chart dir, and reload the chart database.

Let's see them in detail:

Steps 1 and 2:

Say you have a chart in jpeg format called chart.jpg.

From the command line, use:
 convert chart.jpg -colors 127 chart.gif

and then again,
 convert chart.gif -colors 127 chart.tif

and then again,
 convert chart.jpg -colors 127 chart.png

(there is a script that does this for multiple files, get it here , just remove the .doc extension, this is the example)
Throw away the .gif file. Don't ask me why you need to generate it in the first place, but apparently you do, it's an imagemagick thing. Keep the .tif and the .png ones a while longer, though. You'll be even happier to get rid of them when you've finished.

Step 3:

  • Open MapCal.
  • File, Open Image. Open the .png version of your chart. Ignore the data window for the moment, you'll do that later, click OK. You should see your chart.
  • To calibrate it, choose a point near a corner for which it is easy to know lat/lon. Right-click on it, and choose Add New Cal. Point. To zoom in and out use the little + and – buttons at the bottom.
  • Ignore the fact that Latitude has three integer figures, we're still talking about the Earth. Enter the coordinates and proceed for at least three more points, near the corners.
  • Click Activate Changes. Check that the grid makes sense. Click Border, draw a border around the chart (that part is easy).
  • You should also enter some data for the chart: Edit, Chart Information.
  • The Chart Name will show up in OpenCPN to remind you of all your hard work, choose it well.
  • For this example we'll just use “chart”.
  • You should also enter at least Scale (found on the chart) Depth Units, Projection (Mercator most likely) and Datum (WGS84 most likely, but be careful with older charts). All of this information should be found on the chart itself.
  • For more details, you have the SeaClear Manual.
  • File, Save Calibration. Repeat ad-lib for any other charts and exit. If everything went well, you'll find a file called CHARTCAL.DIR in the same directory as you loaded your png chart from. This is used to (finally) make your calibrated chart that OpenCPN will use, as detailed in

Step 4:

  • Generate the chart header from the command line:
    • mc2bsbh CHARTCAL.DIR
  • You should see:
    • Create CHART.hdr
      (the .hdr file must have DOS newlines)
  • So type:
    • tif2bsb -c 127 CHART.hdr chart.tif chart.kap
  • At which point you should have a chart.kap file that OpenCPN will happily use.
      This can be done for many charts at a time by using the tif2bsb batch script from the mc2bsbh page. If it gives you any problem with lowercase-uppercase names, try: 
      for i in `find * -depth`; do (mv $i `echo $i|tr [:upper:] [:lower:]`); done
      which will convert all files in the current directory to lowercase (works great for me).
      If you get an error like /bin/bash^M, no such shell (I did), it's a cr/lf thing, just edit it, type [enter] at the end of each line (there's only 7) and get rid of the blank ones.

Note 1: you can also make the .hdr file “manually”, using a template and entering the calibration data with a text editor, but I won't go into that for the moment.

Note 2 (about the commands, so if there's any problem you know what to look for) :

    convert is a command from imagemagick.
    tif2bsb is a command from libbsb.
    mc2bsbh is a standalone thing.

Note 3: (by Jonasberg, on the colors in the conversions) :

    The "127" is the number of individual colors used. Sometimes it pays of to reduce this number to get a smaller file size, say, if you start with a bitmapped format like png that contains fewer colors.
Note 4: On the joinpcx script:

If you use it "standalone" and not as part of the "charts" script,  change the lines,
convert new1.gif - colors 127 $1.tif
(and .png) to
convert new1.gif -colors 127 `basename $PWD`.tif

(and .png)
because the "$1" will not create files with [directory_name].tif and .png, it won't create any files at all.
Using `basename $PWD`will make files called [current directory name].tif (and .png).
So just edit the script to whatever suits you best.

Chart Conversion

BSB Lib
http://libbsb.sourceforge.net/
libbsb is a portable C library for reading and writing BSB format image files, typically used for nautical charts.
A number of utilities to convert and work with BSB charts are included in the libbsb package. Sample files and instructions on using these tools are available on the Examples page.
  • bsb2tif - convert BSB image to TIFF format
  • bsb2ppm - convert BSB image to PPM format
  • bsb2png - convert BSB image to PNG format
  • tif2bsb - convert TIFF image to BSB image
  • ppm2bsb - convert PPM image to BSB image
  • bsbfix - fix the index table in a BSB file
The mc2bsbh Utility
http://www.dacust.com/inlandwaters/mapcal/
This is a utility to take an image of a chart that has been calibrated with MapCal, and convert it into a BSB chart that can be displayed in many marine navigation programs.
 
KAP-File Utility
http://www.cruisersforum.com/forums/f134/kap-file-utility-38725.html
GUI for the several command line tools such as mc2bsbh and the libbsb tools, (for Windows, sorry Linux and Mac guys).
 

MAPC2MAPC

http://www.the-thorns.org.uk/mapping/
Powerfull utility conversion chart to and from a large variety of formats

For Google Earth
GE2KAP
http://www.gdayii.ca/Downloads/ (password to decompress the archives: phiggins)
GE2KAP - Creates .KAP charts from Google Earth
GERoute - Follows a route to load the Google Earth cache.
C2GPXKML - Converts navigation routes and tracks to different formats.
 
 
Port detail generated by GE2KAP
ChartAid
http://www.bellwoodgroup.com/marine/chartaid/index.htm
Many people have found Google Earth and Google Maps printable images helpful in supplementing their knowledge of a particular area or specific location. The ChartAid program offers you the ability to save Google Maps printable images as Raster Charts or Photo Charts, in BSB/KAP file format.
 
Overlay NOAA raster charts in Google Earth
http://matrixmariner.com/geRasterOverlay
 
Script to Convert MaxSea Routes to GPX
http://www.cruisersforum.com/forums/f134/script-to-convert-maxsea-routes-to-gpx-41010.html

Raster charts classification

RASTOW - RASTER CHARTS ORGANIZER

    
    DESCRIPTION

*** RASTOW *** (raster-stow contraction) classify your raster charts collection (*.kap files) creating 96 subdirectories divided by timezone (15° steps, without any country exception), north and south, above and below 45° of latitude.
    Two modes of creation are available: -copy- or symbolic -link-. At the end of operation, a chartlist.txt containing a catalog of your charts is automatically created. Using -chartlist- command, you can create only a chartlist from your database. In copy mode, the created database may be bigger than the original base because a map can have a part in more than one timezone or <45° to >45° in latitude, and it resides in all the timezone subs covered. So, use symlinks if your space storage is critical.
    Two others commands are useful to organize your collection with datas founded in the file header:
         -update- change the file date to the last update edition.
         -rename- change the filename by the chart title.
    It's a good practice to make an update before a copy or rename command: if two files are equals, only the most recent will be handle.

    About raster charts: theses charts are not so powerfull and practical than vector charts (no more details zooming, more bigger size), but generally come from original charts edited by officials hydrographics services, the source of vectors charts, so, sometime they may have more details than commercial vector charts (see example in marinux website ) or it is usefull to consult its in case of doubt. Some others people have the homesickness of paper chart look and feel, and theses charts keep the same aspect.


   INFOS & DOWNLOAD

http://marinux.tuxfamily.org

Alarm Sounds

A selection of alarm sound files to use as AIS and Anchor alarm.
www.policeinterceptor.com/navysounds.htm

Celestial Navigation

Application: Astronavigation
The Running Fix problem is easily solved using Astronavigation.exe
 animated gif
 

Circles of position or Circles of equal altitude. General scale.


Fix and confidence ellipse. Coastal scale.
Pack overview
Software is available for free, for non-commercial use, at:
  http://sites.google.com/site/navigationalalgorithms/ (Only for Windows®)
Plotting circles of equal altitude:  Method explained
 

Chart Work

Using the GPX utility and the Chart Work family of programs is it possible to do on an electronic nautical chart the work you do in a traditional way.
The three programs are:

  1. Lines of position and Great Circle sailings (orthodromic).
  2. Piloting: Currents and coastal fix.
  3. Search & Rescue search patterns.
GPX output includes:

Coastal navigation LoP

  • Bearing
  • Range
  • Horizontal angle
Celestial navigation LoP
  • Marcq St. Hilaire Line of Position
  • Circle of Position
Radionavigation LoP
  • RDF bearing
Route
  • Great Circle
  • Composite
Piloting and coastal fix
  • Currents Drift and Set
  • Lasheras
  • Ciclonic method
  • Fix by simultaneous Distance and Bearing of same object. Geographic Range, D( waterline, top of object )
  • Fix by 2 simultaneous Horizontal Angles
SAR search patterns – Patrones de búsqueda SAR
  • Expanding Square
  • Sector Search
  • Parallel Search for one ship
Resources:

Chart Work - Lines of Position & GC sailing

 

Chart Work - Traditional paper chart work on an ECS.

Coastal navigation

the three types of lines of position used are:

  • Bearing
  • Range
  • Horizontal angle

 


Fix by three simultaneous bearings.

Fix by three simultaneous bearings. Detail.
 

Celestial navigation

Offshore navigators use celestial navigation,sextant observations, as a backup for the GPS. Use a sextant for taking the altitude of a celestial body and OpenCPN to plot the celestial circle of position instead the LoP -Line of Position-. Repeat this and take at least three sights. You easily can check if any danger is near your fix, and the uncertainty in your position.


Parameters of a circle of position in astronavigation.


Route using the three types of sailings

  • Rhumb Line. Direct with OpenCPN (And also using Plugin Route_pi).
  • Great Circle(Direct in OpenCPN using using Plugin Route_pi).
  • Composite(Direct in OpenCPN using using Plugin Route_pi).
The three types of sailing are also available in ChartWork

Composite Route.


Composite Route plot with OpenCPN.

Radionavigation

RDF or radiogoniometer provide a bearing. Its line of position may be plot using GPX input. Two options:

  • RDF onboard
  • RDF on station
 

Fix by two RDF bearings with OpenCPN.


Chart Work - Piloting

Using the OpenCPN GPX utility and the Chart Work - Piloting program is it possible to do on an electronic nautical chart the work you do in a traditional way.


Piloting and coastal fix

Advanced piloting techniques - Currents

  • Currents Drift and Set
  • Lasheras
  • Ciclonic method (820. Determining Track Made Good by Plotting Running Fixes. Bowditch-American Practical Navigator.)

Coastal navigation
 

  • Fix by simultaneous Distance and Bearing of same object. Distance by:
Geographic Range
D( waterline, top of object ) 
  • Fix by 2 simultaneous Horizontal Angles

Chart Work - SAR search patterns

Search & Rescue utility that generates a GPX file for OpenCPN or Google Earth.



Search Pattern:
  • Expanding Square
  • Sector Search
  • Parallel Search for one ship
  • Parallel Search for two ships

Orientation as an input to takes into account tide, wind and drift.
Number of legs and its length may be configurable.



Free software to create the GPX file that serves as an input to OpenCPN is available at http://sites.google.com/site/navigationalalgorithms/ (Only for Windows®)

GPS Geolocation for Win8 GNSS Sensor

Small GPS Geolocation Application that enables Windows 8 Tablets or Notebooks with GNSS Sensor

It's been tested inside of a fiberglass boat and the GNSS sensor seems to be able to pick up the signal quite well. Hasn't been tested at sea yet.  See the details here: https://bitbucket.org/petrsimon/geolocationtcp/wiki/Home

Code is available at the bitbucket repo, viz the link above.

The program needs to be improved in many ways. Right now it waits for a connection from OpenCPN and then starts to send messages. Once connected, it should start printing "Sent NMEA sentence $GPRMC XXXXXXX". If that doesn't happen perhaps OpenCPN did not connect. Check that the settings in OpenCPN are correct, as I'm sure you did. just press Apply or OK, once you filled all settings. Also have tried the GPS Satellite application to verify that the GNSS sensor works? You'll find it in the Store.
I'll soon make a nicer more user friendly interface what will make it easier to look for problems. Please watch the bitbucket repo for changes.

See "How to use OpenCPN on a tablet windows 8 thread" and Post 7
http://www.cruisersforum.com/forums/f134/how-to-use-opencpn-on-a-tablet-windows-8-a-101245.html#post1341714

GRIB Data and Software

Ugrib

http://www.grib.us
Freeware application Ugrib allows instant and fully customizable access to global weather data. Within one simple to use interface you can download and view weather data right on your desktop.
The data being served at http://www.grib.us/GribData.aspx is from the US GFS global weather model. Its has a native resolution of 0.5 degrees and includes surface winds and barometric pressure. The forecast you get from the webpage is a 7 day forecast with a 3 hour timestep. 

zyGrib

http://www.zygrib.org
Graphical software for Linux, Mac OS X and Windows (GPL3, Qt) to download and display GRIB 1 files.

NMEA Instruments

For NMEA instruments on your onboard PC/laptop, you may wish to try one of the following:
  1. NavMonPC: Closed source, windows only, but reportedly excellent gauges for wind instruments, GPS, AIS display, anchor alarm, etc.
  2. PolarCOM: Closed source, windows, linux, mac; visually appealing gauges for wind instruments, GPS, anchor alarm, etc.
  3. CapCode: Free software, Java-based navigation programme with sailing/regatta focus, supports wind instruments, polars, VMG etc.
  4. Matrix Mariner GPS: Free software, Window and Linux, visually appealing GPS display, some features for GPS handling including live gps output to Google Earth. (Windows version includes VSPE kernel mode virtual serial driver).
  5. VSPE: Closed source freeware, windows only, Virtual Serial Port Emulator enables you to use data from one serialport (such as GPS or NMEA data) simultaneously with several programs. You can run PolarCom, NavMonPC, OpenCPN and other navigation programs at the same time without COMport conflict.
  6. gpsview:Tool for analyse NMEA textual data, allows to load NMEA log files and view data in table, graph and track forms.
  7. Muplex: Open source under GPL, a Linux soft multiplexer that can mix different input flows of real or emulate serial (USB, bluetooth)  NMEA datas and share it between multiple applications, creating virtual serial port and TCP/IP local loop or network, as VSPE for windows.
  8. OSD_Depth: Open source under GPL, a Linux echo-sounder repeater which uses the OSD technique (On Screen Display, everytime "ontop" above any application, using big digits) to display the water depth from NMEA sentences as DBT or DPT in meters, feet, fathoms.

  9. kplex: Open source (GPLv3) software NMEA 0183 multiplexer for Linux, OS X and FreeBSD. Handles serial, pty, TCP/IPv4, TCP/IPv6, IPv4/IPv6 UDP multicast, IPv4 broadcast UDP and file inputs and outputs and performs optional sentence filtering, checksumming and data source prioritisation/failover.
  10. AIS/NMEA Router and Decoder:  Routes AIS and other NMEA sentences between Serial, UDP, TCP, USB, Internet, Log files, TTY Display, and TTY Display Windows.  Free Windows program. AIS Guides. Website with detailed AIS information. PDF showing operation with Opencpn.  AIS Decoding webpage
  11. GeolocationTCP: The sole purpose of this program is to fill a gap for Windows 8 users unable to use OpenCPN with the internal GNSS sensor. The program creates a server which serves NMEA location information based on the status of GNSS sensor. OS/Hardware required: Windows 8 with GNSS sensor. For program download, installation, startup and Opencpn connection instructions, see https://bitbucket.org/petrsimon/geol...ntcp/wiki/Home

Tides

Official sources
1. France, SHOM - http://www.shom.fr/fr_page/fr_serv_prediction/ann_marees.htm
2. United Kingdom, easytide UKHO - http://easytide.ukho.gov.uk/EASYTIDE/EasyTide/SelectPort.aspx
3. United Kingdom, NOC - http://www.pol.ac.uk/ntslf/tidalp.html
4. The Netherlands, RWS - http://www.rijkswaterstaat.nl/geotool/astronomisch_getij.aspx?cookieload=true (including export and print functions)
5. The Netherlands, RWS - iCalendar Tide Wizard: http://live.getij.nl/outlookgadget/php/index.php?field_language=en
6. Germany, BSH - http://www.bsh.de/de/Meeresdaten/Vorhersagen/Gezeiten/index.jsp
7. United States, NOAA - http://tidesandcurrents.noaa.gov/gmap3/
8. Canada, CHS (pdf files) You will find the pdfs on the tide station page -http://www.waterlevels.gc.ca/eng/data/predictions/2013
9. Canada, CHS - http://www.marees.gc.ca/cgi-bin/tide-shc.cgi?queryType=showFrameset&zone=1&language=english&region=4&stnnum=3250

Not for navigation!
XTide -  Harmonic tide clock and tide predictor. Work with X-windows, plain text terminals, or the web.
http://www.flaterco.com/xtide/

WXTide32 - a free Windows tide and current prediction program.
http://www.wxtide32.com/

WXTides Stations - tcdata, (HARMONIC, HARMONIC.IDX), for OpenCPN
http://fserv.skill-club.com/get_1088_156a.html

cTide: tide prediction software for PocketPC's
http://airtaxi.net/ctide/

JTides - an advanced, accurate, easy-to-use tide and current prediction Java MDI (Multi-Document Interface) application.
http://www.arachnoid.com/JTides/

QuickTide - a free Windows tide program specifically made for The Netherlands, especially for the tidal area of the Waddenzee. For Linux: runs under Wine. In Dutch only.
http://www.quicktide.nl/

Weather Routing

These programs do weather routing, and produce a route that can be exported to OpenCPN in GPX format.

OtVlm is a free, opensource, weather routing program, for Linux, Mac and Windows.
QtVlm Documentation and installation
QtVlm Sourceforge Download
OpenCpn Weather Routing Notes on working with qtVlm
OpenCpn Summary of Routes Transfer between OpenCpn and qtVlm, see bottom of page.
OpenCpn Grib Weather Plugin




Bluewater Racing is another free tool (currently only available on windows):

Magnetic compass

Usually a gyrocompass is not available at a yacht. Instead one or more magnetic compasses serve for steering. The reading of this kind of compass must be corrected for variation and deviation.
OpenCPN uses true course over ground. The course to steer is calculated taking into account the wind, the current and the compass correction: magnetic variation + magnetic deviation:
 

Deviation curve of magnetic compass

An analytic method for obtaining the deviation curve of a magnetic compass allowing obtaining the value of the deviation for any course.
Magnetic deviation

Magnetic Variation

Magnetic variation, or magnetic declination, is shown on paper and raster charts, but can also be calculated using the World Magnetic Model. C source code for any platform is available at: http://www.ngdc.noaa.gov/geomag/WMM/soft.shtml

For Windows OS, compilations with a graphical user interface (GUI) are available at:
  1. http://www.ngdc.noaa.gov/geomag/WMM/wmm_gdownload.shtml and at
  2. http://sites.google.com/site/navigationalalgorithms/

A World Magnetic Data PlugIn is available for OpenCPN since 2011.04.03 (version 0.1) at:
http://www.cruisersforum.com/forums/f134/world-magnetic-model-plugin-58167.html#post658775

In the example hereunder (from GUI no. 2 above) the nautical translation of "Declinacion magnética y Variación anual" is: "Magnetic variation and annual change".