Tuesday, October 22, 2013

AIS Spoofing - Should We Be Concerned?

Recently there's been a few posts about fake AIS "tracks" on marinetraffic.com and other web-based AIS tracking sites. Indeed this is pretty easy to do because those sites accept "raw" AIS data over publicly accessible internet ports.

They do that because their data is crowd-sourced by thousands of volunteer "stations" around the world.
Those stations take raw received AIS data streams from an inexpensive AIS receiver and essentially just pipe it from the user's PC to their servers. So anyone with a copy of the AIS specifications could fake those sentences with an ordinary PC and this doesn't take hacking genius or unique skills or knowledge. Of course, this could be diminished by special PC software on the many receive sites that encrypt the data and/or authenticate with their servers and perhaps they will do that.

Although this is currently an issue in the design of the web-based AIS sites, more importantly it points out a potential flaw in people's thinking about what to do with those sites. The web-based AIS traffic sites aren't really designed for navigation or collision avoidance, even though there are some proponents of doing that. Rather, they are designed for viewing vessel traffic for informational purposes. The IMO some time ago even tried to discourage their use - without success due to their popularity. But people using these sites for anything other than monitoring a friend's boat positions or entertainment should consider the potential for both incorrect as well as missing data. These sites rely on monitoring stations which in some areas are sparsely populated and may have delays and coverage gaps.

So, can someone spoof actual AIS transmissions that are then received by an AIS system on-board a vessel? Yes, they could but it isn't the same thing as sending some text strings over the internet. You need an AIS transmitter and you need to control it. Easily available type approved Class B AIS transponders specifically have compliance tests to prevent this. They can only transmit autonomous Class B messages, require their own internal GPS receiver so an external position can't be given to them, and they can't be used to fake a Class A container ship message. Since Class B is single-slot, they can't transmit the multi-slot messages such as those produced by large ships to identify their names and types.

They can't be used to make a "lighthouse appear out of nowhere" as has been reported because AIS aids-to-navigation use a different message type. The Class A shipping and aids to navigations message types, access schemes, and slot timing are different than Class B making this harder to do without the manufacturer's cooperation.

None of this is impossible of course, but probably not so easy with readily available consumer AIS transponders. But of course, someone could buy an AIS base station or develop their own AIS transmitter (perhaps using an SDR platform), or the manufacturer of an existing AIS transponder might have an exploitable interface that someone could use to transmit unauthorized messages.

AIS was always designed to be an open-standard so it would completely function using many different interoperable products. And given it relies on radio transmissions, all you really need to disrupt the system is a high power transmitter tuned to the AIS frequencies. This of course isn't spoofing, but even anti-jamming technology has it's limitations. So would the extra cost and development effort justify resistance to the occasional spoof? 15 years ago it wasn't so easy to develop RF hardware so the answer was probably no, but with the latest technologies it is becoming easier.

In some ways this really isn't all that different from the much-publicized GPS spoofing concerns. What are your thoughts?

Thursday, October 11, 2012

New Signs at Sea - Synthetic or Virtual?

For over 700 years humans have been using various forms of waterborne signs to assist mariners to make safe passage.  These signs, or Aids to Navigation (AtoN) as they are known, include impressive lighthouse structures built centuries ago through to simple floating buoys that passively mark boating channels.

From the beginning governments and more lately international organizations such as IMO and IALA have worked to implement and manage standards that have continuously improved construction, shape, size and colors used by all Aids to Navigation.

Aids to Navigation design has come a long way in 700 years from simple anchored casks floating on the water’s surface to solar powered lights mounted on buoys constructed from plastic.  In the 1930’s a major step was taken in the use of technology when radio beacons were used to transmit from a buoy, allowing mariners to calculate a bearing to the buoy using a radio direction finder. This enabled them to set a course based on the known position of the buoy.  Other innovations even included the trial of an atomic powered light installed on Baltimore Harbor in 1961; it didn’t last!

With over 80 percent of world trade carried by sea and approximately 165,000 to 200,000 AtoN’s being relied upon  globally to “show the way”, efforts will continue in our search to find innovative ways to improve safety at sea.  Some of these improvements to the design and technology used for AtoN’s include the addition  of AIS (Automatic Identification System) mounted on buoys and more recently the transmission of synthetic and virtual marks to indicate the location of a remote AtoN or hazardous location.

A synthetic Aid to Navigation indicates the position of a physical marker, e.g. channel markers, lateral marker etc whereas a virtual Aid to Navigation indicates the position of a location where no physical marker exists, this could be a submerged rock or virtual shipping lane.

These synthetic and virtual marks are transmitted from a platform or shore based AtoN transmitter.  This transmitter allows multiple marker signals to be sent, each mark is created by sending a unique signal from the transmitter’s location.  These transmissions are received by existing AIS equipment installed on all large commercial vessels and many recreational vessels. They are then displayed as a navigational hazard on a ship’s chart plotter or other AIS receiving equipment.  When used to mark a hazard, an AtoN transmitter can alert a ship’s crew that they are on a collision course with the hazard well before they come into visible contact with it.

An AtoN transmitter addresses the need to make physical AtoN and hazards at sea more visible when costly, environmentally unfriendly, physical infrastructure is not appropriate or is impossible to deploy. There are many examples of where a synthetic or virtual mark can be used to protect the environment and improve safety, these include;

  • Marking visible and invisible hazards, including; bridges, marinas/piers, reefs, shellfish beds, underwater pipelines, power and communications cables
  • Marking areas where navigation conditions change frequently, including; sandbars, overhead clearance, ice, water levels, yacht race courses, etc
  • They can even be used to “throw up” temporary cordons around events such as no-go areas, hazardous spills, marine protected areas, etc
We have developed a range of devices designed to help vessels avoid collisions and in 2011 we extended our product offering by developing an innovative new AtoN transmitter called the Virtual AIS Beacon™.This is a natural extension for Vesper Marine as we are a marine electronics designer and manufacturer of safety devices based on the Automatic Identification System (AIS) standards. 

The Virtual AIS Beacon electronically marks hazards at sea in a low cost, environmentally friendly and easily deployable way.  Port authorities, oil and gas companies, offshore wind farms or any organization needing to protect their environment by making shipping hazards or AtoN more visible on ships chart plotters and AIS displays will be the main users of the Virtual AIS Beacon. A case study about how we are helping to protect marine environments in New Zealand can be viewed here or a video can be seen here.

Because of the relatively low cost and simple deployment of systems such as the Virtual AIS Beacon, these innovative products have enormous safety and environmental benefits to the world’s coastlines. Systems like the Virtual AIS Beacon are not a replacement for physical Aids to Navigation but a way to augment the safety and environmental protection infrastructure that is already in place. 

Between 2000 and 2010 there were over 1500 losses of commercial vessels alone. Nearly 20% of these losses were as a direct result of stranding.  This has come at an enormous cost to life, the environment, wildlife and commercial interests over the past decade; with technologies such as AtoN transmitters deployed it’s possible to have a positive impact on this situation.

Friday, September 7, 2012

Comparing & Selecting the Right AIS Transponder

We have compared two dedicated AIS Transponders with their own display (Icom MA-500TR & WatchMate 850)

When comparing consider how you will;


Remove the AIS screen clutter that you get on chart plotters

....and eliminate the unwanted AIS alarms that many systems generate.

In a previous blog (here) we wrote about the issue of clutter on chart plotters and how presentation of AIS information on chart plotters is not always useful especially when in highly congested waterways.  In summary it is about making the right choices for the type of boat you have, the location and distances you will be voyaging and in some cases the experience and number of crew you have.

The AIS Transponder comparisons below look at the WatchMate 850 and  Icom MA-500TR and highlight some of the key differences:

Our desire to make AIS information easy to use has lead us to develop the very unique WatchMate range of AIS displays that are unequaled when it comes to filtering the AIS clutter from displays and eliminating unwanted AIS alarms that only add frustration to your boating experience.  See this in action by watching the video here

Monday, March 12, 2012

Volvo Ocean Race - Welcome to Auckland!

We wanted to be the first to welcome the winner of the Volvo Ocean Race Leg 4 to Auckland. They were expected to arrive around midnight and that would mean getting out and away from the other boats that would be there to greet them.

So we decided to go out to Tiritiri Matangi Island which they would round on the seaward side. It's about 25 miles from Auckland. But we needed a fast boat to even stand a chance of keeping up with Groupama as it roared into Auckland.

Earlier in the day we spent about 15 minutes fitting a WatchMate-850 to our friend's boat. His boat is an old wooden speedboat with an interesting history but it's so dated looking and reminicent of something out of Miami Vice - so although I don't know if it actually has a name - we've always called it the "Don Johnson".

The WatchMate was connected to 12V and a VHF antenna plugged in. The hardest part of the install was finding a few screws on board to fix the bracket securely to the boat. Good thing we did because that WatchMate took quite a pounding as we bashed into the chop of wind against current late last night.

We knew the challenge would be finding the boat that far away from the city and getting close enough to it. It was dark and overcast but warm. Visibility was reasonable and we were able to see a few masthead tricolor lights in the distance. But how would we know which was Groupama? We also knew the Volvo Open 70 would be moving so fast it might be impossible to catch up to it if we weren't positioned well, especially in the swells which made it uncomfortable when going fast in the tiny speedboat.

We arrived in the lee of Tiritiri to wait but it didn't take more that a few minutes. Our timing was nearly perfect. We picked up Groupama on the AIS as it came along the other side of the island. We still couldn't see it but raced to the south end of the island to intersect. And there it came out of dark and from behind the island at 19 knots! We were barely able to keep up at times due to the sea conditions. Stu drove expertly and we had the most amazing ride all the way back to Auckland alongside this incredible sailing machine.

Today we were back out on the water to watch the next three Volvo boats arrive (Puma, Telefónica and Camper). This time it was during the day, a light drizzle, and we didn't go so far out. Instead, we joined the hundreds of other boats of all shapes and sizes chasing them into Auckland.

Tuesday, December 13, 2011

Latest firmware for WatchMate’s includes Digital Selective Calling (DSC)

If you have got a DSC capable VHF Radio or you are thinking of getting one you will want to know more about the latest WatchMate firmware release. WatchMate Firmware V5.04 is now available and it includes DSC calling capability allowing you to connect to a DSC compatible VHF radio.

Using the DSC function from your WatchMate allows you to initiate an “individual station call” to vessels that are displayed on your WatchMate screen. This feature makes it easy to message nearby boats, requesting them to switch to a specific channel for a VHF call.

As with all Vesper Marine firmware upgrades this release is free; you can request this new firmware as an upgrade here. It’s available for the WatchMate 850, 750 or the 670. Sorry it won’t be made available for the older WatchMate 650.

As can be seen in the screen shot to the right using the DSC feature is very easy. Use the arrow buttons to scroll up/down to the desired channel. The last used working channel is remembered and becomes the default for subsequent calls. Use the “Call” button to place the call or “Cancel” to return to the target display without calling.

To date we have verified this feature works with several Icom radios and we expect this feature will also work well with other brands of DSC enabled VHF radios that accepts the NMEA-0183 DSC sentence. We are interested in learning which other VHF radios support this capability. If you have tried this feature and found it to work, please tell us by contacting support@vespermarine.com or visit the support section of our website www.vespermarine.com.

If you want to learn more about the other benefits you get with DSC enabled radios your might like to review;