Below is an graphical overview of Marine-B, an Ethernet based Multi-Channel Inmarsat-B decoder.
Overview of Multi-Channel Inmarsat-B Decoder
Below is a more detailed block diagram of multi-channel decoder with a few screenshots of operational logging and FFT waveforms.
Marine-B is a fully automatic frequency agile Inmarsat-B multi-channel decoder. The decoder supports BPSK for NCS call logging/directing, OQPSK for APC voice demodulation, real time audio output and automated MP3 audio file archiving. It can handle as many voice decoders as CPU capability allows. Initial testing with multi-core i7 Intel CPU comfortable supports 6-12 parallel channels.
The decoder only supports RFSpace SDR-IP or NetSDR SDRs.
Here a a couple of short sample voice decodes (these are generic and do not violate any privacy).
I have been working on some new decoding software that directly interfaces to RF Space SDR-IP or NetSDR. These SDR’s provide wide-band IQ data over Ethernet and are ideal for plug and play operation. All the new decoders are multi-channel and offer simultaneous decoding in real time for multiple protocols, including voice, data and fax for multiple Inmarsat services. More to be posted soon.
Comet ISON is getting closer. Here is an image I grabbed in the early morning hours before sunrise. This image was taken October 18th at the KESA Observatory in Colfax CA. I am in the process of imaging ISON again as it is much closer now (but it’s been cloudy).
A final look at ISON before it’s too close to sun to image anymore. I will take another look in the second week of December assuming it survives the Sun encounter, but with wider angle camera instead of telescope.
There are some nice wide HRPT signals coming from NOAA 15, 18 and 19 (others too, but these are the ones I looked at today). NOAA 15, 18 and 19 are LEO satellites and therefore require real time tracking. Since it’s been a while since i have tracked any LEOs it took some time to get the tracking software operational, not to mention getting the dish calibrated. The signals are pretty good and stable for most of the 10-15 minute pass – suitable for decoding software.
NOAA 18 on 1707 MHz.
NOAA 19 on 1698 MHz.
Not a bad signal from NOAA 15 with it’s omni-directional antenna.
NOAA 15 on 1702.5 MHz.
The signals coming from NOAA 18 and 19 are RHCP and look to be 665.4 kbit/s split phase PSK. I could not confirm this because of the government shutdown.
Here is a quick look at the Lunar Reconnaissance Orbiter (LRO) signal. Even though NASA is shutdown as part the US government shutdown, there is still a good signal coming from the LRO. I was doing a quick 1.2m dish calibration and grabbed this screenshot of some nice doppler just as LRO was passing to far side of the moon. This is pretty weak compared to the larger 2.4m dish. Also, this was using the L-Band Feed and LNA so not very optimal considering LRO is on S-Band.
Inmarsat STD-C is a data or message-based system used mostly by maritime operators. An Inmarsat C terminal transmits and received on L-Band to various geosynchronous satellites that service each major ocean region (POR, IOR, AOR-E, AOR-W). The information rate is 600 bits/sec. The channel is modulated with BPSK at 1200 bits/sec. The ship-based (or aircraft-based) Inmarsat C terminal is called an MES (Mobile Earth Station) while the land based ground stations are called LES (Land Earth Station).
In the Pacific Ocean Region (POR) there are nine different LESs which the following IDs and Frequencies.
201 1539.655 Telenor Satellite Services Inc
202 1539.625 Stratos Global New Zealand Auckland
203 1539.515 KDDI Yamaguchi Japan
204 1539.595 EIK Telenor Norway
210 1539.605 Sentosa Singapore
211 1539.665 Beijing MCN China
212 1539.505 Stratos Burum Netherlands
217 1539.635 Nudol Morsviasputnik Russia
221 1539.615 France Telecom MSC
There is a main Network Coordination Station (NCS) that assigned signaling channels (used to uplink) to the MESs.
The main NCS frequency for POR is 1541.450 MHz.
The NCS channel is also where you will receive Enhanced Group Call (EGC) messages. There are two types of EGCs, SafetyNET and FleetNET; SafetyNET is used for anything related to safety, such as SAR, navigation, coast guard, etc. FleetNET is typically used for distribution of news, weather, incidents, etc.
There is also various data services such as 2-way messaging, email, polling, position reporting and distress alerting.
Here is an example EGC Navarea message:
NAVAREA XI WARNING
NAVAREA XI 0706/13
SOUTH CHINA SEA, SOUTHERN PART.
231415Z SEP. 04-52N 104-05E.
EIGHT PIRATES WEARING MASKS ARMED WITH A
HAND GUN AND LONG KNIVES IN A HIGH SPEED
CRAFT APPROACHED AND BOARDED AN OFFSHORE
TUG UNDERWAY. THEY TOOK HOSTAGE ALL CREW
MEMBERS, TIED THEM UP AND STOLE THEIR
PERSONAL BELONGINGS. AFTER ABOUT THREE
HOURS, THE PIRATES LEFT THE VESSEL. CREW
MANAGED TO FREE THEMSELVES AND THE
MASTER REPORTED THE INCIDENT TO THE
OWNERS. VESSEL RETURNED TO THE PORT OF
DEPARTURE WHERE THE AUTHORITIES BOARDED
THE VESSEL FOR INVESTIGATION. MASTER
REPORTS A POSSIBILITY OF A MOTHER VESSEL
IN THE VICINITY.
VESSELS REQUESTED TO BE CAUTION ADVISED.
Here is an example EGC Distress Alert:
Eik LES 2-OCT-2013 22:25:07 676140
SUBJECT: **406 MHZ DISTRESS ALERT**
MESSAGE: AT 022143 UTC OCT 13,
A 406 MHZ DISTRESS BEACON HAS BEEN DETECTED IN
POSITION 27-37N 139-57.8W.
NO FUTHER INFORMATION HAS BEEN GIVEN WITH THIS ALERT.
VESSELS IN THE AREA ARE REQUESTED TO KEEP A SHARP LOOKOUT,
ASSIST IF POSSIBLE AND REPORT SIGHTINGS TO RCC HONOLULU, HI.
TELEX 392401 ANSWERBACK CG14 UD;
MF/HF DSC 003669993 OR 003669990
Here is an example of email in response to SSAS ALERT test message.
Email addresses and confidential information have been removed.
Date: 10/02/2013 06:23:49 AM
Subject: SSAS ALERT REPORT
Good day Capt,
Well received your SSAS test alert message.
Sent: Wednesday, October 02, 2013 2:22 pm
To: Operations Singapore
Subject: SSAS ALERT REPORT
Inmarsat STD-B service is still active, even after all these years. On STD-B you will find voice, data and fax services Here are a couple of examples of recently received faxes via Inmarsat 3F3 Pacific Ocean Region (POR) at 178°.
NCS Frequency: 1538.230 MHz
Sample FAX via STD-B
Sample FAX via STD-B
Inmarsat Mini-M is also still active, you will also find voice, data and fax services. Mini-M is much more active than STD-B as it is a less expensive service and uses a much smaller antenna/dish. Here is an example of a recently received fax.
NCS Frequency: 1537.330 MHz
Sample FAX via STD-mM
Ever wonder what a food order looks like for a ship at sea?
Each month i’m amazed at the total energy spend, so I think it might make sense to start monitoring things to understand where all the power is going. I settled on a Brultech ECM-1240 system. The system is made up of many strategically placed current transformers (non-invasively track current flow) within the service panel as well as a small controller box that eventually makes the power information available over my intranet.
It took about half a day to install and setup everything. Most of the time was spend carefully attaching the CT probes in the crowded service panel.
Here is a shot of the final install, the main service panel is on the exterior of the building opposite of this wall.
Energy Monitoring Setup.
Here is the ECM-1240 used to collect the current data.
Since the ECM-1240 has no ethernet capability it was necessary to use a ZigBee to ethernet gateway as a means to provide the raw data to server running the software.
Not all the power here is consumed, we have solar power generation that is tied through an inverter back onto the grid.
Solar Power Inverter.
The Solar System can generated about 5-6 KW of power.
Below you can see the raw instantaneous data. Not the “Radio” tap is showing over 1 KW. Solar generation is 4KW and total energy being supplied is about 235W. This is because air conditioning is not running, otherwise the supply would be quick more.
Another “gauge” view of the data.
Any finally, the preferred output via web browser.This is live real time view, but you can also look at historical data.
Web Browser Data.
After about a week of operation, I decided additional channels where required to get the full visibility into all the power consumption, so another ECM-1240 was added.