The Great Big SPOT Thread

[crazybrit]

Originally Posted by SpotMaker

Thank you so much!

Boney's post made my head spin, it was so chock full of wrong information.

Your corrections of his erroneous info are all correct. Thanks!

This week is unbelievably busy both from a work and personal standpoint so I didn't have time to answer him as thoroughly as you did.

As for DangerMoney's poor track performance, it looks like a view of the sky problem, but it is unusually bad. I probably can't tell why without seeing how he's carrying his SPoT.

SPoT-I typically gets about 70% of it's track point's through in typical terrain and typical mounting. This is a "laws of physics" thing resulting from line of site to the Globalstar satellites and such. That's why "Check In" transmits three identical messages. The same unique message ID embedded in the three redundant "Check In" messages does cause those duplicates to get dumped; but in "Track" mode there are no "duplicates" (all messages have different embedded message IDs), the back office won't dump any of them that it actually receives. Simply being in the same physical place, GPS speaking, does not constitute a "duplicate".

SPoT-II transmits some additional info in track mode (at some expense of battery life) that permits missed messages to get reconstructed on the back office, making it appear that far fewer messages were missed. So SPoT-II has better effective track performance.

Apologies if I missed this, I went back and skimmed all posts but didn't find this (if it's been answered maybe someone can give me the post#).

BTW SpotMaker, there is so much good info here, it would be great if you could condense all of the "how it really works' answers into one post and attach that post to your advsig line).

I'm curious how the ability to receive a GPS position factors into the sending of various messages? If I recall correctly the LEDs will blink out of sequence (gen1) at the end of an unsuccessful 'ok' which implies the unit could not get a UPS fix. Not sure about what happens in tracking mode, I expect it just stops sendiing position info? Or does it send some filler message saying it lost gps?

It seemed to me that the main advantage of the gen2 was a much more sensititive gps antenna which presumably increases the #successfully sent messages -> maybe receiving a solid gps location is more of an issue than being able to transmit position???? Not sure. Question.

[Adventure Trio]

Spot 1 mounted in a Spot cradle on a ram mount on the handlebars works great. A recent trip showed a 90% or better tracking rate which made my 8 year old son more relaxed when he could see I was moving. It does not work as well in my tank bag, only 60% success rate because my body is blocking most of the skyward view.

My 2 cents.

-Terry

[SpotMaker]

Originally Posted by crazybrit

Apologies if I missed this, I went back and skimmed all posts but didn't find this (if it's been answered maybe someone can give me the post#).

BTW SpotMaker, there is so much good info here, it would be great if you could condense all of the "how it really works' answers into one post and attach that post to your advsig line).

There's so many questions, but when I have time, I could work on a FAQ.

Originally Posted by crazybrit

I'm curious how the ability to receive a GPS position factors into the sending of various messages? If I recall correctly the LEDs will blink out of sequence (gen1) at the end of an unsuccessful 'ok' which implies the unit could not get a UPS fix. Not sure about what happens in tracking mode, I expect it just stops sendiing position info? Or does it send some filler message saying it lost gps?

It seemed to me that the main advantage of the gen2 was a much more sensititive gps antenna which presumably increases the #successfully sent messages -> maybe receiving a solid gps location is more of an issue than being able to transmit position???? Not sure. Question.

The correlation between "being able to get a fix" and being able to get through the Globalstar network is a weak correlation at best.

There is a slight correlation there, insomuch as if you can't see any of the sky, or can see very little of the sky, you can't either get a GPS fix or get a message through to Globalstar.

To get a GPS fix, you need a clear view of 3 or more GPS satellites, to get a fix with decent accuracy, you need 4 or more.

To get through to the Globalstar network, you need a clear view of at least one Globalstar satellite and that satellite must also have a view of one of Globalstar's ground stations.

(Assuming you're in Globalstar's coverage area, to start with), on average, due to the number of satellites, number of ground stations, etc. it's a little more difficult to get a message through the Globalstar network than to get a GPS fix.

So, there are conditions where you can get a GPS fix, but not get a message through the Globalstar network. But, because the satellites are moving in the sky, the conditions for getting a message through are constantly changing. Even if you can only see a little bit of the sky, eventually a satellite will be in the right position for a message to get through. This is why we transmit every 5 minutes in SOS mode. If you have any view of the sky at all, SOME of those messages will go through!

There are also conditions where you cannot get a GPS fix, but occasionally CAN get a message through to Globalstar! An example of such a condition is where you can see a tiny crack of the sky, such as at the bottom of a narrow crevice. The crack is not large enough to ever see 3 or more GPS satellites, but from time to time, briefly, you may hit a Globalstar satellite. Such a condition is more unusual than the other way 'round (can get a GPS fix but not get a message through Globalstar), however.

GPS fix indication SPOT-1: After a few minutes into the mode, if the LED's blink together, you got a fix and transmitted the last time you tried, (in track mode, you (try to) get a fix and transmit it every 10 minutes, for instance) if they blink out of sync you didn't. Same in all modes. (Although in SOS/911 mode and Help mode it transmits without GPS coordinates even when it doesn't get a fix.)

GPS fix indication SPoT-II:

• GPS LED off, Message Sent LED Off - Unit has just powered up the GPS subsystem and is searching for satellites. (All modes.)
• GPS LED Green, Message Sent LED OFF - Unit sees 3 or more GPS satellites and is calculating it's position from them. (All modes.)
• GPS LED Red, Message Sent LED OFF - Unit has been trying to get a GPS fix for 15 seconds or more but sees fewer than 3 satellites. If possible, try getting a clearer view of the sky. If not possible, the LED may well flip to green soon, it will just take a while (due to the imperfect view of the sky). (All Modes).
• GPS LED Green and Message Sent LED Green (blinking together). Unit got a GPS position fix and transmitted it to the Globalstar network within the last few seconds. (All modes).
• GPS LED Off and Message Sent LED Green. The last time that the unit got a fix, it was successful and was transmitted. In a "repeating" mode, like Track, the LED's will stay this way until the next cycle (every 10 minutes in Track), then the sequence above will repeat. In one of the single message modes (e. g. OK/Check), the LEDs will blink in this configuration for an hour. You know when the OK/Check or the Message 2 cycle is done (and it's safe to power down the unit) when the OK check or Message 2 light stop blinking. The "message sent" LED blinks for a while longer as a confirmation that it worked.
• GPS LED Red and Message Sent LED Green (Help and SOS modes only). The unit didn't get a fix, but in these emergency modes, it transmitted an emergency message anyway, without GPS coordinates. It will attempt to get a fix again on the next 5 minute cycle.

[boney]

I really screwed the pooch on that one didn't I?

I have some questions then.

Originally Posted by HogWild

Boney, you're responses are full of incorrect information.

Wrong! I have a pile of track marks right here at my home at this very moment.

Why is it that when I used the Spot Shared page I never saw more than one tracking point in a location even though I had been there for many tracking cycles? It appeared as if a bunch of them were dumped, with only the latest numbered tracking point shown?

Originally Posted by HogWild

Wrong satellite system. Spot uses Globalstar, which makes a big difference when you look at number of satellites and coverage.

Yes, yes, Globalstar.

Originally Posted by HogWild

Depends on if you have the Gen 1 or Gen 2 unit.

Yea for improvements!

Originally Posted by HogWild

It can work at an angle. But the more you tilt it, the less sky it can see. So, a little tilted may give you slightly fewer tracking points. If what you said was correct, the Spot would be horrible on an often leaning bike.

You said the same thing I did only you worded it differently.

Originally Posted by HogWild

Wrong! It can jiggle all day long and still work fine the whole time. Hard mounted might even make things worse in a rough off-road situation, as hard shocks and vibration can cause battery connection problems, as I've already experienced (RAM mounted).

Sure it can jiggle around all day, but if you don't have it placed securely you run the chance of it changing position on you and losing it's ability to get the signal out, thus defeating the point of carrying it.

Originally Posted by HogWild

Wrong! The manual says 20 minutes, not 15. And if you're "mother" isn't watching for your "Okay" text message, then you DO need to wait the full period to be sure that message gets through. Then, you don't just ride, you have to make sure it's out of Okay message mode, then put it into track mode.

You sure like to make mincemeat out of a quote, if I didn't know any better I say you were a journalist... I'm under the impression that it's 15 minutes, but having not made reference to my manual today, I cannot make further comment.

Maybe you couldn't see over your overeagerness to jump on my mistakes to read the post correctly... I clearly said:

Originally Posted by Boney

If you have the spot mothership text you your own location, then you'll know when the Okay message goes through and you can go straight to tracking and get your ride on.

What this means is that no matter how much time has elapsed since you put your unit on Okay mode, once you get the text, your Spot has it's own location and is functioning correctly. There would be no reason to wait the rest of the 15 or 20 minutes for the full Okay message cycle because like you and SPOTMAKER confirmed, the redundant signals from there on out would be dumped. It's working correctly; put it in tracking and get going. Perhaps SPOTMAKER can clarify this one.

Wrong! "Never" is incorrect unless you can't see any of the sky at all, or in a few special cases near the edges of the coverage areas. It's more of a statistical thing, when the signal may not get to the moving satellite at one moment, but it may get through from that same tough location another moment because the satellite(s) moved.

Please, you're splitting hairs. If I put an "almost" in there, I would have said the same thing as you.

If you read their material carefully (they don't say it's 100% perfect), and FOLLOW THE DIRECTIONS, then it works pretty much just as advertised. It's nearly impossible on a bike to mount it where it has a full view of the sky all the time, so you're likely not to get near perfect results.

For the record, I'm satisfied with my Spot. I'm one of the people who did read the directions (it's been a while, so I'm sure you'll show me some slack on a point or two). Then I experimented with it, putting it in different locations on my bike, mounting it differently, hanging it on my belt (why on earth does this thing come with a belt clip when they don't work well mounted vertically?). "They" don't say it's 100% perfect, but then again, the material included in the package when I bought mine glossed over a lot of the key details to it's use. If one goes to their web site or reads the email newsletter, one might get the impression that it does work flawlessly. Perhaps better information on it's correct usage and limitations would have prevented all those 1 & 2-star ratings from people who were completely dissatisfied.

Needless to say, I apologise to those I confused.

[sector]

Originally Posted by crazybrit

BTW SpotMaker, there is so much good info here, it would be great if you could condense all of the "how it really works' answers into one post and attach that post to your advsig line).
.

crazybrit, that's a nice idea. And anyone who would like to hurry that project along could compile the FAQ from this thread themselves and send it along to SpotMaker to apply final edits on and post. Don't you think? Shoot, I'm still hoping my question will get answered by somebody!!

[SpotMaker]

Originally Posted by boney

I really screwed the pooch on that one didn't I?

I have some questions then.


Why is it that when I used the Spot Shared page I never saw more than one tracking point in a location even though I had been there for many tracking cycles? It appeared as if a bunch of them were dumped, with only the latest numbered tracking point shown?

Leaving a SPoT lay out on a table, or a rock, or a sidewalk outside in Track mode is exactly how we check both throughput (how many messages get through) and accuracy (what's the radius of the "clump" of points we get when the SPoT actually lays in one place).

The back office does not dump points simply because they are "close" to one-another. Assuming it's TRACK mode, as opposed to OK check, you will get a small "clump" of points (all at the "same" location with up to a few feet of error each) if you leave it in track in one place.

Originally Posted by boney

What this means is that no matter how much time has elapsed since you put your unit on Okay mode, once you get the text, your Spot has it's own location and is functioning correctly. There would be no reason to wait the rest of the 15 or 20 minutes for the full Okay message cycle because like you and SPOTMAKER confirmed, the redundant signals from there on out would be dumped. It's working correctly; put it in tracking and get going. Perhaps SPOTMAKER can clarify this one.

The stats work out something like this:

• Odds that any one message will get through: ~75%
• Odds that at least one of two consecutive messages will get through: ~90 - 95%.
• Odds that at least one of three consecutive messages will get through: ~99.5 - 99.9%.

So, this is why we send 3 messages on a check-in message. The randomized wait of 5 to 10 minutes between the messages is very important too; this wait is allowing the Globalstar satellites in view to change position in the sky between messages. This change, depending on how much of the sky is in clear view, can make a huge difference as to whether one of those messages gets through.

If you are in cell phone coverage, and you've set your SPoT account to send check in messages to your cell phone (along with others), indeed most of us set up our account that way, mine is set up that way... Then, yes, if you receive the text message on your cell phone, the message has gone through and you may go back into track mode.

BUT... If you're sending check-in messages via SPoT it's probably because you're somewhere in the boonies outside of cell phone coverage! (That's one of the main things the SPoT is for!) So, if you're outside of cell phone coverage, your cell ain't gonna get the text (until you come back into cell coverage).

So.... waiting for the OK/Check cycle to finish (OK/Check LED stops blinking) is the only way to be 99.5% sure your message got through.

Of course, one reason some people send OK/Check messages is to mark a point of interest so we can go to our SPoT web page and find it easily on Google. (I do this). If you're doing something like this inside of Cell coverage, indeed, once your cell jingles with the message, you can flip back to track and move on.

[drewjb7]

Originally Posted by SpotMaker

Or vice versa.

>Some GPS units will interfere with the SPoT. The SPoT will interfere with >some GPS units.

>Two different models of GPS units may interfere with one another.

>Some combinations have no interference issues at all.

>To be on the safe side, SPoT should be 12" from another GPS based >device, like the guide says.

Interfere how? What would be the effect on either the SPOT or the GPS?

It's not that unusual for me to have my SPOT, GPS (Etrex), cell phone and radar detector (Solo2) within less than 12" of each other. Signal overload? They all seem to work OK other than the occasional unexplained beep from the radar detector.

Drew

[boney]

Leaving a SPoT lay out on a table, or a rock, or a sidewalk outside in Track mode is exactly how we check both throughput (how many messages get through) and accuracy (what's the radius of the "clump" of points we get when the SPoT actually lays in one place).

The back office does not dump points simply because they are "close" to one-another. Assuming it's TRACK mode, as opposed to OK check, you will get a small "clump" of points (all at the "same" location with up to a few feet of error each) if you leave it in track in one place.

I must be confusing your interface with the Jason Jonas site. Actually, it looks like that has changed also, or somewhere some of the data is missing. Or somewhere along the line the track becomes truncated.

If I go back and look at a trip from last June there are clearly data points missing from the track where they would have stacked up at a break. Even the numbers jump a few digits(this is on the Jason Jonas site). However a track from August has each and every one, even when they're stacked up on each other. I have to admit though, that I stopped using and sharing maps that are generated by spot- so now that I have my Spot sitting outside "testing" I do see that the tracks are stacking up in one place on the spot page, as they are on the Jason Jonas site.

BTW, the time from turning on my spot and setting the okay mode to the time I got a text for it's location was about 4 minutes.

[Pedro Navaja]

http://www.spotadventures.com/trip/view?trip_id=181994

Just testing out the SPOT Adventures blogging website. Not sure I like it yet. Seems like it's just easier to post the ride report here at ADVrider. Editing the blog seems cumbersome and it seems to post things that I don't want it to post, like dates. I don't think that each entry needs to be the date that I actually make the entry. I should be able to write the diary retroactively like I can here at ADVrider after the ride. That way I don't have to be in internet cafes while I am on the ride, unless I am weathered-in like today. It's supposed to be a blog, not a ship's log. I would also like to parse my way points retroactively as I see fit. I'll spend more time looking at the site after I finish my leg back to Houston as I might not be giving SPOT Adventures a fair shake. But for now, I think I just like the screen captures of the way points from the shared page and just dropping them into an ADVrider RR.

Yes, I have read the manual and have had the unit over a year. Still I got bitten by the OK/Tracking snafu, i.e., tracking won't start if the OK message hasn't completed yet. Now I just go straight to tracking. I'm not waiting around for 10 minutes for the OK to go through at start-up. Note on the blog how the OK went through from Houston, but no way points down to Laredo even though I had two blinking lights at every gas station stop. So don't give me the two blinking lights for tracking if OK hasn't completed. And no, I am not running back inside to log on and see if the OK went through and I am not waiting for a cell phone test message. It's time to ride. Capisce? Next day I just went straight to tracking, and dumped the suggestion to start the day with an OK message that you SPOT people suggest in the manual. It tracked fine from Laredo to Parras de la Fuente without doing the OK message first, and tracked back to Laredo the same. Put that in the manual why don't ya.

Work on the switching logic here SPOT people. Stop with 2,3, and 5 second counting nonsense on the buttons. How fast do you say 1-Mississippi? And how do you even spell it? And also, instead of letting the credit card expire, send out a fricking e-mail message of the expiry before the lapse instead of leaving the warning internal to the SPOT account. I mean how hard would that be, since you have the e-address tied to the account?

Nevertheless, I still support the use of the product, and my wife likes that she can track me on the web.

Cheers,

Mike

[TomW]

Originally Posted by boney

Quote:


Sure it can jiggle around all day, but if you don't have it placed securely you run the chance of it changing position on you and losing it's ability to get the signal out, thus defeating the point of carrying it.

Not to flog the dead, but I'm curious. When you say 'changing position', I assume you mean flipping over so that the antenna is not oriented properly (face up), right? I think we're all agreed that jiggling isn't going to affect SPoT's performance as long as its antenna is right side up.

Cheers.