In my last blog post, I referred to Portvision CEO Dean Rosenberg’s blog post which clearly articulated the benefits and limitations of terrestrial and satellite AIS. In today’s post, I wanted to look at the limitations that were outlined for satellite AIS and how the launch of ORBCOMM’s next generation OG2 satellites is going to change these.

According to Dean’s blog post, satellite AIS has three limitations…

1. Lower Reporting Frequency

“While terrestrial AIS can report vessel positions in near-real-time (with multiple updates each minute), satellite AIS has significantly higher latency and lower frequency of reporting. Current satellite AIS service providers typically provide position updates on specific vessels only a few times each day. While this lower frequency of reporting still provides compelling value to track the progress of ships at sea, it does not allow for many of the advanced alerting and reporting features that are available with terrestrial AIS.”

What Changes with the Launch of OG2 Satellites?

Latency of the AIS data delivery is affected by the size of the satellite constellation and the ground station infrastructure. When the satellite receives an AIS message, it stores the message internally until the satellite becomes connected to a ground station. The satellite then downloads all the messages received since the last ground station connection.

With the launch of 11 more next-generation OG2 satellites and ORBCOMM’s existing network of 16 ground stations, data latency for some areas is expected to go as low as 1 minute!

2. Limited Detection of Vessels

“The ability to detect AIS signals from space is currently an imperfect “art”. Electromagnetic interference (particularly in dense areas) often limits the ability to detect vessels in congested areas, even when vessels are transmitting their AIS signal.”

What Changes with the Launch of OG2 Satellites?

The laws of probability come into play when looking at the likelihood of detecting an AIS message via satellite. The probability of detecting an AIS signal increases as you spend more time over the vessel or more satellites pass over a vessel. With the launch of 11 more next-generation OG2 satellites, ORBCOMM will offer more satellite passes which will increase the detection rate of vessels.

3. Cost

“It is expensive to launch a satellite, and the commercial satellite operators need to recoup that investment. As such, satellite AIS typically carries significantly higher licensing fees than terrestrial-only AIS providers.”

What Changes with the Launch of OG2 Satellites?

Since AIS is just one of the services offered by the ORBCOMM satellite constellation, we are able to offer more flexibility in our plans and services compared to other satellite AIS providers.

If you would like more details about how ORBCOMM addresses satellite AIS limitations, I recommend you download our latest white paper. You can also contact me – I would be more than happy to answer your questions.