What GPSANGLER does

The software was developed in response to the need for a chart plotting program aimed squarely at anglers and divers. Using a GPS device, it plots the vessel and fishing target positions on a user created chart image. A depth sounder may also be utilised to create a 3D image of wrecks or other underwater features. The product is dedicated to the investigation of wrecks, reefs etc. for a successful day on the water. 

Getting Started

You will need a laptop PC running Windows XP or later, with at least 2GB of RAM and a screen size of 1024 (minimum) X 768 (min) pixels. Faster performance is obtained if the machine has a solid state disk drive. About 300MB of disk space is required for the software and, (the major part), the data; it depends on how many charts you need to work with. The system has been extensively tested on a Panasonic Toughbook CF-19 with 2GB RAM and a 120GB SSDD, yielding good response times. A note about solid state disk drives; if you haven't got one - get one! They're about 40GBP on Ebay and currently represent the most cost-effective upgrade available. Anyway, onwards........         

The software may be downloaded from   https://sourceforge.net/projects/gpsangler/   . The download includes the sister product OSMDCON.

If you have installed OSMDCON previously, please perform the following:

a) Extract the downloaded file into a temporary folder by specifying e.g. C:/temp as the target.

b) Copy the folder C:/temp/IMAGE_PROCESSING/GPSANGLER into C:/IMAGE_PROCESSING ,  creating C:/IMAGE_PROCESSING/GPSANGLER .

c) Go to "Continue" below

Otherwise,

Extract into a folder named C:/IMAGE_PROCESSING by specifying C:/ as the target.

Navigate to "C:/IMAGE_PROCESSING/lib/setup/setup.tcl"

Edit with a Text Editor the file setup.tcl near the top as follows:

# new user? please change this..........
 
 array set env [ list SSDD   H:  ] ; # or delete this line if no SSDD
 

# end SSDD

Change the drive letter on the SSDD line to the drive letter of your Solid State Disk Drive, e.g. E: , or delete the line completely if no drive present. (Delete the line if C: is a SSDD). 

Now download Tcl/Tk from the Activestate web site. Be sure to choose the x86 version of release 8.6.4.1

Start the resultant .exe file and install into the folder C:/Tcl (the default).

Download tcllib-x.xx.zip from the Sourceforge site. Unzip into a temporary folder and run installer.tcl in that folder by simply clicking on the file, as you would for a normal .exe or .bat file. Apart from loading some required extensions to Tcl, this proves the successful installation of Tcl/Tk.

Now run AAA_setup.tcl in the C:/IMAGE_PROCESSING folder. This sets an environment variable for Tcl/Tk, and downloads more required Tcl "extensions".

Continue

Download and install "Irfanview Image Editor" from the Irfanview site . This product is used in the chart creation process.  

Download and install the virtual serial ports emulator at freevirtualserialports.com and create a virtual serial "bridge" by clicking on the "Create Bridge" icon. We are aiming to create a connected pair of ports whereby 2 programs can communicate with each other; e.g. emulating a Windows program at one end and a GPS hardware device at the other. The concept will be used in "demo" mode, see later. Repeat the exercise to produce another serial bridge. Confirm, via the Windows Device Manager, that four "HHD Software Virtual Serial Ports" exist, e.g. COM2 , COM3 , COM4 and COM5 . 

Recommended System Changes 

i) To maximise the available screen area for user programs, including GPSANGLER, we can "Hide the Taskbar". Open the Taskbar Properties dialog box by right-clicking a blank area on the taskbar, (a thin band at the bottom of the screen), and then clicking Properties. Make sure both the Always on top and Auto hide check boxes are selected. This reduces the taskbar to a much thinner line at the bottom of your screen. To redisplay the taskbar, drag the mouse to the very bottom of the screen. 

ii) It is much easier to follow the movement of the mouse if the "Mouse Pointer Trail" is turned on. To turn on and adjust the mouse pointer, open the Mouse Properties dialog box by clicking Start, clicking Control Panel, and choosing "Printers and Other Hardware". Then click Mouse. Click the Pointer Options tab. Under Visibility, click Display pointer trails. To adjust the length of the pointer trail, drag the slider. (The longer the better!). 

iii) To avoid excessive screen flicker, click Start, and right click My Computer. Select Properties, Advanced. Select Performance. Ensure that "Show window contents while dragging" is unchecked. 

iv) To avoid the text of GPSANGLER "leaking" off the right side of the screen, ensure that the Windows setting for Font Size is set to normal or 100%.
This setting is accessed in Control Panel, Appearance and Themes, Change the screen resolution, Appearance. Alternatively, the text size in GPSANGLER can be changed at start up.

For Operating Systems other than Windows XP, the above may well be different..........  

Processing

GPSANGLER uses a hardware GPS device to process the current position of the vessel. Optionally, it will also utilise a Depth Sounder to handle the depth of the underlying water. These 2 devices may be emulated in software to demonstrate the scope and functionality of GPSANGLER, hence the requirement for the serial "bridges" created earlier. Edit with a text editor the file AAA_GPSDRIVER.tcl in the GPSANGLER folder. Let's say we created 2 serial bridges of COM6<->COM7  and  COM8<->COM9 . Examine the following lines:

# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
# ports for NO Multiplexing.......
 set com_port "COM3" 
 set depth_com_port "COM5"
 set muxing "N"

Change, if needed, com_port to one of the ends of a serial bridge, and depth_com_port to one end of the other bridge:

# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
# ports for NO Multiplexing.......
 set com_port "COM7" 
 set depth_com_port "COM9"
 set muxing "N"

Save and exit, then start AAA_GPSDRIVER.tcl . You should see an image similar to:

Good. This is a little program that simulates a real GPS device and a real depth sounder. Set the speed to ~2.0 for the time being......

Now let's start GPSANGLER, i.e. AAA_GPSANGLER.tcl . It initially displays

Click the SET PARAMETERS button and set the GPS PORT  to the other end of com_port above e.g. COM6. Set SOUNDER PORT to the other end of depth_com_port, e.g. COM8. Click APPLY and the following is displayed:

Set the date and time if required and click DONE.

Let's examine what is being displayed here. The left-hand panel shows information about current vessel position, the target position when set, the nearest tide station and various other data. The turn indicator panel (with OK to the left) is used to show how the boat should be steered to reach the target position. Right, let's select a test chart to display instead of the global background. Left click, either in the left-hand panel or the turn indicator panel, to display the drop-down menu:

Select "NO" to "create depths db cache".  

Angling and diving spots are hereinafter termed "targets". A target may be selected from a pre-recorded list, or by clicking on the chart image.  Notice how the GPS position of the mouse is displayed in the left panel. By right-clicking on the chart, we can set a temporary target of a known wreck or other feature. The following is displayed:

Notice that information concerning the target is now displayed in the left-hand panel, plus a 3D view of the area around the target. The 3D view may be manipulated with the associated buttons. The turn indicator tells us to steer Left, so adjust the <STEER> <LEFT< button on GPSDRIVER until the degrees in turn indicator are near zero:

We're now on course for some serious fishing! Or in our case some expensive ragworm drowning........ Adjust the speed of the boat to quickly reach the vicinity of the target, then reduce the speed to ~0.2 knots. After "criss-crossing" the target area several times, with the depth set to a range of say 6 to 7 metres, we will see something like this:

Yeah yeah - I've changed the theme in mid-flight.....  Anyway it gives you an idea of what to expect. The green "pole" is the vessel position. The image is updated every 30 seconds. You will almost certainly have to fine-tune the center of the target area to coincide with the middle of the wreck. When you're happy, the target can be permanently recorded for future selection. Simply "SET TEMP TARGET AS PERMANENT" via the drop-down menu and fill in the details.

Now let's look at the "depth plotter" window. Using the drop-down menu, select SELECT DISPLAY(S)  > DEPTH DISPLAY:

The controls are pan left, restore to "live" display, pan right, and depth range. The box displaying 14:58 is the time of the depth reading at the cursor position. A right click at this position will set a new target corresponding to the vessel position at this time. You can therefore easily set a target if you spot an interesting trough or peak on the display. The software will hold depth and time data for the whole session.

Here we've panned left and spotted an interesting drop in the sea bed. Might be worth investigating!

You may like to familiarise yourself with the functions and options of GPSANGLER for a few minutes..........

OK, let's look at charts; how to create them, how to calibrate them, how to use them.

Charts

The first thing to do before actually getting onto the water is creating chart(s) for your area(s). We can create chart images from scratch using the sister product OSMDON, or we can utilise your existing images with a little "doctoring".

OSMDCON

Refer to the OSMDCON documentation for guidance on creating charts based on OpenSeaMap. Note: Near the end of the file "processing_values.inc" there is a line "set gpsangler n" .  Change this to 

set gpsangler y  

to create a high definition depths database for the chart area (recommended if you intend using the depth sounder features of GPSANGLER).

After a run of OSMDCON, copy the files (e.g.) Thames_Estuary.cha , Thames_Estuary_DEPTHS.png and Thames_Estuary_DEPTHS.DB from the PNGS folder to the GPSANGLER CHARTS folder.

Using Existing Chart Images

Any raster chart image in one of the common formats can be set up for use in GPSANGLER. Use IrfanView, or a good alternative, to change the image format to .PNG  if required. Then the top left and bottom right GPS cordinates of the image need to be calculated in (-)ddd.ddddddd format. Use http://www.gpscoordinates.eu/convert-gps-coordinates.php for this. Place the coordinates in a one line file named (e.g.)  My_Cod_Grounds.cha in the following format:

top_left_longitude  top_left_latitude  bottom_right_longitude  bottom_right_latitude  99  L

For example,

-2.83447265625 50.722546833647947 -2.4390506744384766 50.499506699616653 99 L

Then we need to create a high definition depths database for the chart area, (recommended if you intend using the depth sounder features of GPSANGLER). We accomplish this by running AAA_CREATE_DEPTHS_DB.tcl  in the C:/IMAGE_PROCESSING folder.  Select the .cha file you created above. A "master" DEPTHS.DB is required for this, created in the OSMDCON facility.

You should end up with 3 (or 2) files as in the Thames_Estuary example above. 

On the Water

For use on the water, we need at least a real GPS device, and hopefully a depth sounder too.

Change the port parameter(s) to the real address of your devices. If you want to bypass any processing concerning a depth sounder, simply set DEPTH SOUNDER to N . The SOUNDER PORT address is then ignored.

Set the DBT OFFSET to the difference in depth of the transducer and the normal water line. However, if this offset is automatically included in your device, set DBT OFFSET to 0.0  .

Click ACCEPT when done..........

 Now quickly exit GPSANGLER, as it will complain that no NMEA sentences are being received!

Or you can check that the GPS functionality is working if you have the device to hand at home.

Notes

Use C:\IMAGE_PROCESSING\TCL_COLOURS\COLOUR_DISPLAY.tcl to show the colour range available in Tcl. Left click a "colour band" to copy that colour to the clipboard. Note colour names are case-sensitive.

The system will apply the current tide height to the L.A.T. depth values read from the depths Database. It uses Wxtide32, see the web site http://www.wxtide32.com/  . Ensure that Wxtide32 chooses a tide station that accurately reflects the tide state for your charts! There is help in C:\IMAGE_PROCESSING\lib\TIDES\USE_THIS_FOR_HELP.tcl .

To be updated................. 

Disclaimer

The depth data at EMODnet is reasonably accurate at depths over 10 metres. At depths less than this, it's erratic to say the least.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  The author assumes no liability for damages arising from use of this program OR of any data that might be distributed with it. 

You should not use this program or any data files that might be associated with it if anyone or anything could come to harm as a result of an incorrect depth or tide indication. 

In addition, please visit http://www.emodnet-bathymetry.eu/data-products/disclaimer .

Note that EMODnet uses GEBCO data, either absolute or interpolated, to fill gaps in the 200X200 metre grid.  

Acknowledgements

Recognition and thanks are due to the authors, creators and suppliers of the following:

The OpenStreet(Sea)Map project

Wxtide32.exe

imgkap.exe

surfit

EMODnet data

GEBCO data

Tcl/Tk and associated extensions

Contact

 The author can be contacted at:

gdpound at msn dot com

Please do not hesitate to request help or advice, no matter how trivial you may think it is!

In all cases, feedback is always welcome.

Thanks for using the software.