Showing posts with label expedition. Show all posts
Showing posts with label expedition. Show all posts

April 30, 2015

The Russian Navy gave me an idea, and it uses morse code.

I'm not sure this is going to make any sense without some background information, so let me put things into perspective and maybe it'll be more obvious to you where I'm coming from.

The Russian Navy has a military presence all over the world, working with their allies, in joint operations, exercises, underwater research missions, etc. Several of these missions are not combat missions, and aren't covert at all. Russian Navy ships include oilers, research vessels and tugs; feeding, doing underwater research, and towing their armed military vessels around. As the Russian Navy auxiliary chugs along, they use Morse code (YES!) every six hours to report back to Mother Russia (Россия-Матушка) their location, sometimes the water's salinity, the weather, and other interesting information. These transmissions are mostly unencrypted and can be listened in on by anyone with an HF radio who's tuned to the right frequency. Following these transmissions you can plot exactly where an auxiliary vessel is going, or has gone, unless they go silent during a rendezvous with a SIGINT vessel off the East coast of the USA, hypothetically...

Andrew Roos did a fantastic trip up to Labrador by car, and had the ingenuity to make his own GPS map app beforehand. I really like the project, and hope to have his app (Birdseye) installed before setting out to Goose Bay this fall. There is one thing it doesn't do tho, and I think it's something I should look into... interface with a transceiver.

I have a SPOT Satellite tracker, for my own safety as well as my family's piece of mind, but it also costs ~$170.00CDN every year. I guess safety and piece of mind is worth it, but I find it annoying at the same time. Satellite communication is available all the time, but it shouldn't be the only recourse when you are out of cellular range. Shouldn't there be another way beacon where you are? Especially if you're mobile and have an unlimited 12V power source (ie, the alternator of your vehicle?)

How about transmitting your position to everyone in radio range, over HF (or VHF?), at high power, hourly, using morse code, at a slow 40 CPM? This is modelled after the Russian Navy beaconing every six hours, or the SPOT tracker beaconing every 15 minutes. The message would broadcast vector, speed, height and coordinates, maybe even loop a few times, and use a minimalist format.

(PS, this morse recording was received by Tom, in the UK, while the Nikolay Chiker was about 7,000 km away)

An explanation of the Russian Navy morse format can be found here:
http://i56578-swl.blogspot.ca/2014/10/about-m32arn-morse.html

But WHY do you want to do this Stef?

For the same reason you'd have a SPOT tracker; to let your people know you're on the move, or stationary, as you travel. If you fall off the face of the earth, there would also be a documented route you had been taking, and people could retrace your steps. This sort of system would work pretty much anywhere because of the reach of HF (or VHF) signals. If you had a base station set up to receive these beaconed morse messages back home, you might be able to record and publish your progress on a blog or other dynamic social media facility.

Looking at how a GPS outputs NMEA data, it's probably easiest to embed the RMC output in morse and just send it along. The message contains the time, date, location, speed and track vector; that's everything I want to send in one neat and tidy package, except I'd rather it use typical Canadian units of road transit measure (Km/h, decimal coordinates, etc)

RMC - NMEA has its own version of essential gps pvt (position, velocity, time) data. It is called RMC, The Recommended Minimum, which will look similar to:

$GPRMC,123519,A,4807.038,N,01131.000,E,022.4,084.4,230394,003.1,W*6A

Where:
     RMC          Recommended Minimum sentence C
     123519       Fix taken at 12:35:19 UTC
     A            Status A=active or V=Void.
     4807.038,N   Latitude 48 deg 07.038' N
     01131.000,E  Longitude 11 deg 31.000' E
     022.4        Speed over the ground in knots
     084.4        Track angle in degrees True
     230394       Date - 23rd of March 1994
     003.1,W      Magnetic Variation

     *6A          The checksum data, always begins with *
     ( more: http://www.gpsinformation.org/dale/nmea.htm )

AIS Transponders work similarly, broadcasting positional data, vessel information, and destination data over "Marine" VHF frequencies; 161.975Mhz (87B) and 162.025Mhz (88B), but they only broadcast with 1W, 2W and 12.5W of power, having a maximum expected range of ~40km at sea.

Amp up the same idea using morse over 10M Ham bands (28.000-29.690Mhz) or 2M Ham bands (144-147Mhz), and I expect it would go much farther.

Bob Bruninga already came up with APRS, Automatic Position Reporting System, and it covers some of what I'd like to do, but relies on repeaters to bounce the traffic around to an internet gateway. It reminds me of Link 16 or some other military tactical radio network. Rather than using a network of peer transponders, I'd like to have more of a point-to-point or hub and spoke, along with the disadvantages that come with it, like spotty reception over long distances. Essentially, I want to mimic what the Russian Navy is doing in the ~8Mhz and ~12Mhz range. The Russians are broadcasting direct, without the use of repeaters, and without the vulnerability that comes with that crutch - after all, if your repeater fails, you can't communicate anymore. Conversely, if you're in a valley, you might not be able to get your signal out to the intended recipient either - that's the advantage of a repeater on top of a hill near that valley...

Stretching this one out to my own practical example, I hope to drive from Carp, Ontario to Goose Bay, Labrador this fall. Carp to Goose, as the crow flies, is ~1425km.


Can I put together a system, that I can use, to transmit automatic computer generated morse, from a mobile rig, at regular intervals, with a reasonably sized mobile antenna, and be received at a high point in Carp, at least a few times a day, along the whole journey? I'm going to need to discuss with some HAM enthusiasts.  This may be a project bigger than I'm able to tackle this year.

March 14, 2015

Old GPSes just keep on truckin'

Trimble Transpak II (c) 1993 P/N 19437-60 
I picked up a Trimble Transpak II and a Trimble Pathfinder a while back on eBay, and never did get around to sorting them out and getting them mounted in the Suburban.  I think it's time I took a stab at that again.  Maybe I should back up and explain how I got here.

First, the specifications:

Trimble Transpak II
Copyright 1993
v4.20 Firmware
6 L1 band (1575.42 MHz) receiver 
External Serial Data Port
Internal Antenna / External Antenna Port
9-32VDC 5W Power
P/N: 19437-60
Trimble Pathfinder Basic
Copyright 1990
v3.14 Firmware
6 L1 band (1575.42 MHz) receiver
External Serial Data Port
Internal Antenna / External Antenna Port
9-32VDC 5W Power
P/N: 14992-60


How many GPSes does a guy need?

It seems like all electronic communication or internet-ready devices are coming with built in GPSes these days.  On my last trip I had an iPad, a Playbook, a Blackberry, a Holux M-1000 data logger, and a Garmin dash-mounted GPS... all with built in GPS functionality. So why do I need another?  Well, maybe I don't, but I discovered most of the devices quickly lost functionality when I was out of cell/data range, and these old GPSes never had such a crutch.  They also dont have maps in them to get out of date, which is great - but navigating the roads with them isn't very handy.  What they are really good at is telling you when you're getting close to a pre-designated waypoint, OR tell you where you are within 10 feet.  Yes, these devices from the early 1990s, when the Seattle Grunge scene was at the top of the charts, and the first Iraq war, perform better now than when they initially hit the streets.  Why?  Well, at the time the US military, who control the GPS satellite constellation, were "fuzzing" the signal with a technique called Selective Availability; so it would wander and not be very accurate. They stopped doing so on May 2, 2000 - supposedly permanently.  These units are ruggedized, and look like they could be thrown out of a moving tank in the desert and keep on working. I'm not sure how waterproof they are, but they are at least water resistant.

For power, they take a lead acid rechargeable battery pack, 8 AA batteries (AA battery pack shown in the pictures above), or car-cigarette adapter for 12V power; but interestingly will take anywhere from 9-32V.  So, you can power these things off a 24V NATO power source, a 12V civilian vehicle, or... I don't know what would put out 32VDC..?

Another funny quirk came up; Y2K and planned obsolescence.  Both of these Trimble receivers are on the list on non-Y2K compliant devices, so why didn't they explode on January 1st 2000?  Evidently the GPS signal has at least three parts to it (I'm sure there are more than 3 but I haven't looked up the standard, if it's even published in sufficient detail) The coordinates are independent of time or date; they continue to be accurate down to 0.1 arc seconds (10 feet according to Brooke Clarke's web site - Thank you Brooke!) and I haven't noticed any issue with coordinate precision.  Then there's the time, which is accurate to the second, as far as I can tell.  However, the date is way off - I'm not sure when Trimble expected these units to last for in the field, but 2015 wasn't planned for.  On March 12th 2015 the date read July 27th 1995.  If anyone can explain this I'd really like to hear it.  I presume there's some math involved that can explain it and the date chosen isn't random.

So, why again?

Well, provided I can hard wire the power to it in the Suburban, and mount it in a tidy fashion on the dash, it will function as an interesting talking point, an excellent timepiece, and a backup GPS that will surely never fail.  It's lasted this long, it'll last through the apocalypse.