Another GPS option for PolarView & PolarCOM

May 5, 2011

Just recently I got a chance to order and use another compact USB GPS receiver – ND 100 by GlobalSat.

This receiver uses the same drivers as it’s cousin – the ever popular BU-353 about which I previously blogged here.

Since I already have the Prolific chipset drivers installed, ND-100 worked right out of the box. In my test it quickly acquired a fix and provided position to within about 5 feet – all *indoors*. It also appears to have a bit less of a stationary “course drift” than my BU-353s, though that could be individual device issue.

The primary advantage of this device is a form factor – rather than being a GPS “mouse” it is a “USB stick”, the size of average external flash drive, though it feels a bit heftier. It fits well into my netbook and avoids messing with wires. That said, one drawback may be that it requires additional space to the side of netbook, least it catches onto something and pops out of the USB socket. No big deal though, it can be plugged right back in – and no harm done. PolarCOM will reacquire the connection shortly.

All in all another good option, available on Amazon for about $35.


New Support Site

March 31, 2011

A long-overdue support site for Polar Navy applications is now available at support.polarnavy.com

This site will serve as a central point for all product and technical questions. It will also host documentation and articles with answers to many common questions on PolarView and PolarCOM use.

 


Buying and installing S63 charts from ChartWorld

May 17, 2010

This article is out of date and remains here for archiving purposes. Buying and downloading S-63 charts from ChartWorld can now be done with a click of mouse directly in PolarView

S63 vector charts are produced primarily by official government hydrographic agencies around the world. They are sold through a number of value-added resellers. I buy my S63 charts from ChartWorld. In my experience, they have been the most accessible and their ordering process is relatively straightforward. Disclaimer: I don’t have any connection to ChartWorld, other than being their customer from time to time. Note, that while basic principles described here would apply to ordering S63 charts from any other source, specific details may differ.

Step 1
To buy charts at ChartWorld, or any other S63 chart distributor, for that matter, you need to have something called “User Permit”. “User Permit” uniquely identifies your chart viewer or navigation application software installed on a specific computer. S63 charts that you order, will be encoded using this value and could only be used on the same computer and with the same software product for which they were issued.

In PolarView your “User Permit” is shown in a text box in the lower right portion of Chart Manager. Look for a long hexadecimal string, as seen in a screen capture below.



Screen capture of Chart Manager, showing User Permit on the lower right. Your User Permit will be different! Use one from your system, otherwise your would not be able to install S63 charts!

Step 2

To order charts, you need to open an account at Chartworld.com. You will be asked for your User Permit during account set up process. Copy and paste “User Permit” exactly as shown in PolarView. If you make an error while submitting this value, ChartWorld web site will usually tell you – but don’t rely on this.

– Press “Register” button under login box on the top right of ChartWorld.com home page. Enter your personal details and submit. A new account would be created and details will be emailed to you. Your account login name is generated by ChartWorld and is usually a short string like “AB123”.

– Log into your new account. Click on “myACCOUNT” button from the menu button list. You will arrive at a page sub-titled “My Installations”.

– Click on “new installation” link. You will be presented with a form to enter details of your computer and software installation.



Sample installation page filled with details. Make sure to use your own “User Permit” value!

Note the “ENC User Permit/Backup” field. ChartWorld permits up to 2 different “User Permits” per installation. If you provide 2 “User Permits”, any charts you order for this installation will be supplied with keys issued for both of these permits. You will be able to use these charts on up to 2 installations of PolarView.

– Now that you have set up your account, click on “SHOP” button from the menu button list. There will be a “Search” box on the left hand side. You can search for charts by entering keywords such as place names or chart identifiers. For example, you can search for Virgin Islands or for specific chart cell names, if you know them.

– Search results will present you with a list of matching charts. For each chart you will see one or more prices listed on the right hand side. Prices are in Euros. These prices reflect different durations of chart update period. During the update period, you will be able to download any updates to your charts. Shorter update periods will cost less.
Note, that charts you buy do not stop working after update period is over. They will remain available and continue to work in PolarView. However, you will no longer be able to download these charts from ChartWorld – so make sure to have appropriate backup.

– For the British Virgin Islands each chart cell was priced at Euro 5.71 (about $7.50) for a 3 month update period at the time of last check.  NOTE: chart GB302006 is being replaced with chart GB402006, which should be available on ChartWorld shortly. I will post an update here, when available.

– Before adding charts to shopping cart, click on “Select Installation” button above and select installation you created in the first step.

– Add charts to your shopping cart by clicking on price/update period icon on the right hand side. When done, click on “GOTO BASKET” link above. You will be forwarded to your shopping cart and will be able to complete chart order with a credit card.

Step 3
Once your order is complete, ChartWorld will send you an email with link to download chart and permit files over FTP. Here is what this file list looks like for British Virgin Islands charts:

GB302006_DATA_10_1_0.ZIP.S63
GB52020A_DATA_10_1_0.ZIP.S63
GB52020B_DATA_10_1_0.ZIP.S63
Polar_DC3300_20100119.zip.prm

There are three files. Two of these files, with extension “.S63” are chart archives. The file with extension “.prm” is an archive that contains “Cell permits”, essentially – keys to unlock your charts. All of these files are Zip archives, even though they have unusual file extensions.

– Download these files. Rename each file by removing an additional “.S63” or “.prm” extension, so that they all have extension “.zip”.

– Unpack these archives in a location where you would like your charts to be installed.

– Chart cell files (with names beginning with “GB”) will extract into a sub-directory ENC_ROOT. You can extract all chart files into the same ENC_ROOT sub-directory. If your Zip archiver program prompts you to do so, agree to overwrite any files that may already be there. These overwritten files are not important for purposes of our installation.

– The last archive will contain a few files, of which you need one, called PERMIT.TXT. Extract this file to any convenient location of your choice.

Step 4
– Launch PolarView and open Chart Manager. Click on a “Manage Permits” button on bottom right. This will open a new window – Permit Manager.

– In Permit Manager click “Add” – a file dialog will open. Browse to location where you saved PERMIT.TXT file and select it. PolarView will read this file and install “Cell permits” for charts your purchased.

Permit file from our example above should install 3 chart permits, one for each chart cell. These chart permits will be listed in Permit Manager.



Screen shot of Permit Manager with new licenses added (and one expired license from previous installation).

– Close Permit Manager. Now, back in Chart Manager click “Add Directory” button, and navigate to disk location where you extracted S63 charts.

– Select ENC_ROOT sub-directory and press “OK”. PolarView will scan your selected directory for S63 charts. It will add all new charts to the list. At that point, your S63 charts should be installed and visible in the main chart window.

That’s all there is to it. Make sure to keep a good backup of all chart and permit files you order.


Chart Legend

March 2, 2010

An item that’s been missing from our documentation so far is a chart legend for our vector chart rendering. Turns out – it’s not quite as easy to assemble, as I hoped. With all the effort we put into chart appearance and readability, there was little time left to organize and catalog our icons.

So, finally, here are essential symbols for our charts – IALA regions A and B (in day-time palette colors).

A few symbols in this list are new or updated based on user feedback, to improve visibility as well as to better reflect buoyage of IALA A region. They will be available beginning with the next version of PolarView.


PolarCOM “True” Wind Calculation

February 5, 2010

When used with “relative” (apparent) wind data source, PolarCOM provides two modes of “true” wind calculation. These modes are labeled “STW” (Speed Through Water) and SOG in the configuration. STW is a “traditional” method, used by most hardware wind instruments. It needs no GPS input and requires STW and HDG (your vessel heading) to calculate “true” wind. It also results in an approximation of “true” wind.

SOG mode provdes more precise “true” wind calculation, but it also requres COG as well as HDG. That means you still need a heading sensor to calculate “true” wind – having only GPS input without heading is not sufficient.

If you are interested in explanation as to why that is, read on:

Let’s say you have the following –
1. Relative apparent wind (from VWR/MWV NMEA sentence) as delivered by windvane
2. GPS information including COG/SOG.
3. nothing else

Consider this – your vessel is heading in some direction which is most likely NOT aligned with COG. Relative wind is a vector that you can calculate based on a coordinate system that has boat heading as one axis (and another axis perpendicular to it).

On the other hand your SOG (and SOG induced “wind”) is a vector that by itself can only be considered in a system with one axis along the COG (and another perpendicular).

Without heading there is nothing to reconcile these two systems and no way to do any reasonable operations on these vectors. You need heading to convert one of these vectors to the coordinate system of the other.

Here is a practical example using PolarCOM. The first set of dials (img 1) shows COG and heading that differ by 20 degrees. The true wind is calculated here based on SOG (and using both COG and HDG to adjust vectors). You can see true wind both relative to the boat (second dial from the left) and as an absolute direction (last dial on right). There is no STW (as the heading dial shows).

Img 1

On the second image (img 2) I adjusted heading to match COG. This is what would effectively happen if you used SOG for true wind calculation but did not have an adjustment angle (and assumed direction of travel matching heading).

It is quite clear that true wind resulting from such calculation is not the same as the one that results from properly accounting for COG/HDG difference. And the difference is not insignificant – 30 degrees and about 40% stronger.

Img 2

Incidentally, third picture (img 3) shows calculations using STW and heading. I set STW to be equal to SOG, which is not necessarily true, but it helps make an example simpler. As you can see it is also incorrect, but the result is essentially the same as when using SOG alone without proper heading. I.e. there is no gain in calculation precision.

Img 3



Linux Installation Instructions

January 22, 2010

Linux version of PolarView/PolarCOM requires no specific installation process. Download installation tarball to your disk, then follow steps shown in the following screen capture. Click on the image for better view.

Screen Capture of PolarView Linux Installation

Screen Capture of PolarView Linux Installation

Your Linux distribution must be “sufficiently modern” and have GTK2 available.

32 bit vs. 64 bit

Our applications are provided in “32 bit” version for widest compatibility. This allows our products to work on both 32 bit and 64 bit systems. On Linux, many 64 bit distributions do not come with preinstalled 32 bit compatibility libraries, so you may need to install these libraries before using PolarView or PolarCOM.

– Ubuntu & Debian users need to install one compatibility package. The following command usually does the trick: sudo apt-get install ia32-libs
 Users of Ubuntu 11.10 and above, please note that Ubuntu switched to a new version of OpenSSL. You will need to install previous compatibility version of OpenSSL by running: sudo apt-get install libssl0.9.8

– Fedora & RedHat users have a few more steps to take, see the following link for details: http://beginlinux.com/blog/2009/09/installing-32-bit-support-into-64-bit-fedora-11/

Gentoo users (of 32 bit systems) may encounter a different issue. Seems like on Gentoo libpng version 1.2 may not be installed by default. The following magic incantation should help: emerge libpng:1.2 –oneshot

Uninstallation

To remove PolarView from your Linux system, use “rm -rf bin” on the directory where you have installed PolarView. (This paragraph is placed here due to requirements of Google AdWords – we honestly don’t think you are that ignorant 😉 )


Linux Version Support

January 20, 2010

It’s been a while, and now our Linux products are up to date and synchronized with Mac and Windows releases. We hope you find this new version useful and, as always, welcome questions and feedback.

As an open system, Linux comes in variety of distributions, aimed at different audiences and providing diverse functionality. From desktop to servers and embedded devices – there is a Linux out there to fit the need. This wide diversity brings with it distinct issues that are specific to each Linux distribution, makes troubleshooting and issue resolution more difficult.

Bear this in mind when using our Linux products. Download, install and try them. Make sure they work well on your preferred brand of Linux. If they do not – feel free to contact us, but remember that issues not specific to Polar Navy products may be difficult to resolve.

Having said that – we are glad you are here, and will do our best to make Linux users feel welcome.