Simple 3dB dipole VHF AIS Marine Aerial from co-ax cable

Here’s how we make an AIS tuned 3dB gain VHF aerial using RF-coax cable.
Buy a 5 or 10m length of  50 ohm RF coax cable with bnc connectors already attached – this makes two – http://www.amazon.co.uk/dp/B00JVUP0L4. Cut to required length. Strip back the outer coating at the cut end to a length of 44.4cm + 5cm to make a loop (1/4wave for AIS frequencies). Pull the inner core through the outer sheath and lay the outer sheath back along the length of the coax and trim to 44.4cm. I add a couple of cm to the length so I can bend the tip of the inner core back on itself to hook it over something. Make sure the length of the inner is 44.4cm excluding the looped over end. Cover in heat shrink wrap if you want to make it waterproof and you have a 3dB gain AIS Aerial.
There is a useful video here showing how to do it here :-
and a photo of a 5m long one we made earlier.
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Here’s the live reception from one of these we made and hung up on a window in a friends apartment in Singapore

You could also go one step further and make a 6dB  collinear like this from Neil Arundale (I have made and used one of these too and it compared equally with a £120 commerical collinear).

I hope that this inspires someone. If you get connected up please consider sharing your AIS data with us. We can provide a dedicated port and web view like the one for Singapore above.
http://pocketmariner.com/ais-ship-tracking/cover-your-area/

ShipPlotter AIS sharing to Boat Beacon and Pocket Mariner

Its very easy to set up using the UDP/IP peer to peer sharing feature in ShipPlotter’s I/O settings. See screenshots below. Select enable in the UDP/IP peer-to-peer output, enter the IP address 54.204.25.151 and Remote Port number 5322 (see area circled in red).

ShipPlotterBoatBeacon

Click OK when finished. You will return to the main program window. Click on the “Start” button and you should then see your data on this web page:-

N.B. If you would like your own dedicated UDP port number and web view to share to please email us at support@pocketmariner.com

Dual Channel VHF AIS receiver for under $35 – Boat Beacon, AIS Share and RTL-SDR

Screenshot_2016-03-03-09-53-17 (1)

Got an Android phone? Want Screen Shot 2016-03-04 at 12.32.24a dual channel VHF AIS receiver for under $35? Now there is one thanks to our Boat Beacon app and the Android AIS Share app from ebcTech! All you need is  an RTL-SDR USB dongle,  an android OTG cable , the AIS Share app and our Boat Beacon app and you can see all the ships out to 30NM away (depending on height above sea level). No need for an internet connection, this is a  truly standalone full featured AIS receiver and with Boat Beacon’s new NOAA US Marine charts you have an AIS chart display with Collision detection and alarms too. It takes just a couple of minutes to set it up the first time and then after that it works out of the box. Here is what you need:-

The RTL-SDR USB stick is a software programmable radio receiver and because of its popularity for use in picking up TV and fm radio broadcasts it is incredibly cheap. As low as $10.  It is so powerful it can pick up and demodulate both AIS VHF frequencies at the same time. The one we recommend is the RTL-SDR.COM stick which is around $25  and has several major improvements over generic brands including use of the R820T2 tuner, improved component tolerances, a 1 PPM temperature compensated oscillator (TCXO), SMA F connector, aluminium shielded case with thermal pad for passive cooling and a telescopic aerial that you can extend to the correct length for AIS reception – 44.4 cm.

Next you need an Android OTG cable that lets you attach the RTL-SDR USB dongle to your Android device. They are typically less than $4 and we recommend the Y shapeScreen Shot 2016-03-04 at 12.36.44d ones which allow you to keep your device charging at the same time as using the RTL-SDR dongle.

Make sure you have our Boat Beacon downloaded and installed . Next download and install the AIS Share app from the Play Store. Set up of AIS Share is pretty straight forward  (setup video for those who like watching youtube here ):-

Installation / First start

Install the driver app from Google PlayTM store.
Get it on Google Play

https://play.google.com/store/apps/details?id=eu.ebctech.rtl_sdr_ais_driver
Start it one time. After that you can close the app ( RTL SDR AIS Driver )

Install AIS Share
Get it on Google Play

https://play.google.com/store/apps/details?id=eu.ebctech.ais_share

Start the AIS Share app go to the setting activity

AisShare Dongle Settings

Set the PPM setting
This is really important. For the RTL-SDR.COM USB stick that we recommend this will always be 0 as it comes with a stable pre-tuned oscillator. Google it
Set up the UDP Share

Start the driver with the pink floating action button.(please do not start / stop too fast , if you have clicked one time .. wait a second )
AisShare start

Then check if you are receiving messages.

Finally, launch Boat Beacon, go to settings, scroll down to Local AIS, select UDP, then tap on Local AIS Port and enter 10111. AIS Share will continue to run in the background as long as the USB dongle is attached. Watch the ships sail by 🙂

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Screenshot_2016-03-03-09-53-17 (1)

 

There is also a short video showing the two apps in action together made by  ebcTech here https://www.youtube.com/watch?v=p68y68Lqqgg&feature=youtu.be

Boat Beacon now has all NOAA US RNC (Raster) Marine Charts available

Pocket Seamless_RNCs_chartMariner were invited to help NOAA with their new raster charts service. We met up with them in the US last year and have been working with them on the trial. NOAA’s Raster Navigational Charts (RNCs) are produced by NOAA’s Office of Coast Survey (OCS) and are designed for marine navigation, but can also be used as a marine base map by GIS users, coastal and ocean planning staff, and the general public. NOAA raster navigational charts (NOAA RNC®) are full-color digital images of NOAA paper charts. They provide a consistent view of the marine environment, but with more than 2,100 individual chart and inset files available, finding the right chart at the right scale can be time consuming.

The trial aimed to create a map service of all 2,100+ raster navigational charts and their insets. The charts display as a seamless mosaic with the map collar or neat line—the information around the chart providing scale and notes—removed. Also, the map service displays only those charts appropriate for the viewing scale and map extent requested (from 1:5 million to 1:1,000 scale!). The seamless NOAA RNCs within the service are updated monthly and represent the most recent version of the RNCs and their respective Notice to Mariners at the time of the update.

The trial has been a great success and we are now busy rolling out the new service to use in our Boat Beacon, SeaNav and Boat Watch apps via a simple In App Purchase. This gives our customers access to all 2,100 charts including all updates. The charts for a region automatically download when you view an area and we cache them locally on your device so that they display instantly the next time you look at the map and will also display when you are not connected to the internet. This also means customers using Boat Beacon as a display for external AIS receivers like Digital Yachts or the new and very competitively priced dAISy one  ($59 – $41) can use Boat Beacon on their boat without needing an internet connection.

Boat Beacon on iOS is first out of the block with support for US NOAA raster charts. You can get it here :-

https://itunes.apple.com/app/boat-beacon-ais-marine-navigation/id494877039

Boat Watch iOS is next and we hope to have Boat Beacon on Android with US raster charts ready shortly following that. We can also add seamless raster chart options for the UK, Ireland, France, Netherlands and Germany – please let us know if you would be interested so we can raise the priority to get the work done – email us at support@pocketmariner.com or answer our quick 3 question survey here 

https://www.surveymonkey.co.uk/r/8CFCWD2

If you want to check out what the charts look like for your area before getting them in our apps you can use the Raster Navigational Charts Google Earth Tool. This is a Google Earth file of all the charts and insets available and is updated monthly along with the map service updates. Clicking on a chart outline gives you information about that chart, such as title, scale, and date updated. Plus, you have the option to overlay in Google Earth a collared or a collarless version of the chart by clicking on the respective preview link.http://nosimagery.noaa.gov/rnc/NOAA_RNCs.kmz

Here are some screen shots from Boat Beacon on an iPad with the US NOAA raster charts around Miami:-

Pleasure Craft Azura selected (note the track in red and our unique trip detail feature which includes departure point as well as the standard destination info – Fort Lauderdale to Key West).

Screen Shot 2016-01-20 at 15.11.31

In this screenshot we have tapped on the mid channel Safe Water mark Aid to Navigation (AIS AtoN) on the approach to Miami (MIAMI LB M). All AtoN’s which have AIS available are selectable on the charts and will show distance and bearing from your location.

Screen Shot 2016-01-20 at 15.12.00

You can instantly toggle the charts on and off:-

Screen Shot 2016-01-20 at 15.24.46

dAISy AIS receiver with Boat Beacon on Android and Mac

daisy

 

We have been trying out the new and very inexpensive  dAISy AIS vhf usb receiver with our Android Boat Beacon app. It works great – straight out of the box. Just connect dAISy to an aerial and to your Android device via an android OTG cable, Boat Beacon automatically shows up as an app to pick to work with it, select Boat Beacon and make sure Local AIS via USB is turned on in Boat Beacon’s settings and receive local live AIS data straight into Boat Beacon. No need for an internet connection to see ships around you. I use an OTG cable with a power connector so that I can keep my device charged and use the external AIS receiver at the same time.

We have also tried using dAISy with our Mac SeaNav Marine Navigation app via USB and it also works very well.

dAISy is really well made in an amazingly small and durable aluminium metal box ( 63 x 44 x 23 mm – size of a matchbox )  and retails for the incredibly low price of  $59 (£41).  It is only single channel. It does channel hop but it will only receive half as many messages as a dual channel AIS receiver, so it can take twice as long to acquire a target or get an update to its position. But dual channel receivers cost at least double this and most are 4 to 5 times as expensive. It is available here:

https://www.tindie.com/products/astuder/daisy-ais-receiver/

Here’s what Adrian, dAISy’s creator has to say about the range and sensitivity compared to other far more expensive AIS receivers:-

“dAISy did perform better than the RadarGadget AIS USB dongle and a cheap SDR dongle. One customer reported that dAISy’s performance is comparable to NASA AIS Engine, though I didn’t have an opportunity to verify that myself.  Range in the real world is hard to quantify as it relies so much on antenna, location and radio noise. In general, with a proper VHF antenna, line of sight works well. Boaters with the antenna on top the mast report a range of approx. 17NM, that’s also a typical range that I see from unobstructed shore-based stations. .”