Waas 138 (51)

[+GPSlug]

Anik F1R is now transmitting corrections on PRN 138 (Garmin 51) in test mode. So you on the northern east coast should have something to use for the time being.

 

135 (48) has been coming in and out recently. It's out at the moment.

[RubiconJW]

I've seen it on & off for a few weeks..

My question is: How depednable is the info it's providing?? Considering it's in a "test" mode raises a lotta questions on my part... Are the airlines using its data when it's available?? Do they have a means of over-riding the data feed ?? do we??

trudge..trudge..trudge..YAHHHH..thump..

I guess they moved that vertical drop

 

..jw

[+zahadoom]

I've seen it on & off for a few weeks..

My question is: How depednable is the info it's providing?? Considering it's in a "test" mode raises a lotta questions on my part... Are the airlines using its data when it's available?? Do they have a means of over-riding the data feed ?? do we??

trudge..trudge..trudge..YAHHHH..thump..

I guess they moved that vertical drop

 

..jw

 

Ive never seen it yet. Im in southwestern ontario. But I was up near 80deg. today and I was noticing on the sat map, there were no birds north of me.

Is that true?

[+GPSlug]

I've seen it on & off for a few weeks..

My question is: How depednable is the info it's providing?? Considering it's in a "test" mode raises a lotta questions on my part... Are the airlines using its data when it's available?? Do they have a means of over-riding the data feed ?? do we??

trudge..trudge..trudge..YAHHHH..thump..

I guess they moved that vertical drop

 

..jw

In practical terms, the source of the corrections should be the same as the older sats. So if it's there it should be fine as long as you don't use it for safety-of-life applications.

[+PDOP's]

Love these new satellites high in the sky in the south.

 

[+whitecrow]

How far south?

No see here in Eastern Pennsylvania.

[+Red90]

All WAAS satellites are over the equator.

[+whitecrow]

"How far south was tongue-in-cheek", heh.

I can see 33 now & then here on the east coast but 33 works better for Europe as I understand it (or not).

We have no waas sats for the east coast.

[+Red90]

You should be able to see 51.

 

http://www.lyngsat.com/tracker/anikf1r.html

 

It is at W107.3 and easily covers the entire US.

 

edit: I see you have a Cx...... They don't like to see the new WAAS birds..... You need a non "X" model....

Edited May 4, 2006 by Red90

[+whitecrow]

Well, I had an Etrex Legend.

[+Red90]

It should see it fine. No problem with my Vista.

[+zahadoom]

It should see it fine. No problem with my Vista.

 

I have a new Cx model! I sometimes see 33. But thats it. Don't tell me the new Cx's don't see the new waas birds period,please no.

 

I never got any answers about birds north of 80 here in Ontario. Seems weird the East coast doesnt have a WAAS bird. New York State is a large chunk of population.

[planewood]

35 is still winkin and blinkin in the ESE out here west of Houston. Haven't seen any other WAAS birds flying around.

 

Still no D's with 35 but with a 8'-9' EPE it surely is sending out some kind of corrections. But, I'm get an 8'-9' EPE with WAAS disabled??? Go figure. Actual accuracy is that, or better, and sometimes worse.

[Twilight Error]

It should see it fine. No problem with my Vista.

 

I have a new Cx model! I sometimes see 33. But thats it. Don't tell me the new Cx's don't see the new waas birds period,please no.

 

I never got any answers about birds north of 80 here in Ontario. Seems weird the East coast doesnt have a WAAS bird. New York State is a large chunk of population.

The east coast did have a WAAS bird - #35. It was moved by its owner to the west coast to provide better coverage over the pacific. The replacement bird is apparently in orbit and sending test signals, it is expected to be fully operational this fall. From southeast Ct, I see #35 and 48 on occasion, never get a signal lock on them though. #33 shows up frequently and I do get a lock on that one. 51 is new, I've seen it listed on the northern horizon, but have yet to recieve a signal.

[+PDOP's]

The replacement bird is apparently in orbit and sending test signals, it is expected to be fully operational this fall. ... 51 is new, I've seen it listed on the northern horizon, but have yet to receive a signal.

51 (PRN138) would be the new WAAS sat for the east coast. As for seeing it on the northern horizon that also happened initially with the other new WAAS sat as discussed in this thread.

 

From the FAA website WAAS Inmarsat GEO Coverage Starting in Fall 2006

[+GPSlug]

51 went away again, came back unhealthy, and is now gone again; with maybe some other events in between I didn't see.

 

I never got any answers about birds north of 80 here in Ontario.

At 80 degrees latitude, you should see some of your sats from over the other side of the North Pole. The GPS orbits only go as far north as about 55 degrees, if you're any farther north than that, you'll never see any that are at your same latitude and are north of you.

 

If you look at PDOP's's's image about 10 posts up, you can kind of see a circle above the zenith point where there are no satellites. The farther north you go, the more that hole will move to the middle. If you look at a sky plot like that with some software that shows you all of the satellite tracks for the whole day, the circle is very obvious.

 

The question that remains, though, is how you can be north of 80 and still be in (or anywhere near) Ontario?

[+Red90]

 

I have a new Cx model! I sometimes see 33. But thats it. Don't tell me the new Cx's don't see the new waas birds period,please no.

 

I never got any answers about birds north of 80 here in Ontario. Seems weird the East coast doesnt have a WAAS bird. New York State is a large chunk of population.

 

I'm sure they will see them when they are out of test mode. I can get 35 and 47 with my 60Cx, but it mever looks for the newer ones. Garmin says that they are working on changing the search method for these new models. The two new satellites PanAmsat at W133 and Anik F1R at W107.3 will cover the content fine. They just aren't in full operation yet.

[indygpser]

35 is still winkin and blinkin in the ESE out here west of Houston. Haven't seen any other WAAS birds flying around.

 

Still no D's with 35 but with a 8'-9' EPE it surely is sending out some kind of corrections. But, I'm get an 8'-9' EPE with WAAS disabled??? Go figure. Actual accuracy is that, or better, and sometimes worse.

 

Well, #35 is currently located at 142 degrees west; therefore, #35 is located SW of Houston and not ESE. Apparently, your GPSr is searching for #35 at its old position which was ESE of Houston. My 60CSx is also searching for #35 in the SE direction from here in Indianapolis. Hopefully, Garmin will fix this problem with the next firmware update.

[planewood]

35 is still winkin and blinkin in the ESE out here west of Houston. Haven't seen any other WAAS birds flying around.

 

Still no D's with 35 but with a 8'-9' EPE it surely is sending out some kind of corrections. But, I'm get an 8'-9' EPE with WAAS disabled??? Go figure. Actual accuracy is that, or better, and sometimes worse.

 

Well, #35 is currently located at 142 degrees west; therefore, #35 is located SW of Houston and not ESE. Apparently, your GPSr is searching for #35 at its old position which was ESE of Houston. My 60CSx is also searching for #35 in the SE direction from here in Indianapolis. Hopefully, Garmin will fix this problem with the next firmware update.

 

Yep, I'm aware of that. I did a hard reset of the 60cx and it still shows up in the ESE. When I went to northern Oklahoma, it even moved down a little on the horizon. There was one day about a month ago where it showed up in the SW and I even got D's on that day. But, never since.

[+Timpat]

I got a solid lock on #35 today in Albany, NY and got corrections on all my SVs. I was using my 60C and from my location it was WSW at a low elevation of less than 10°, but it gave me all Ds. (I was on a downtown rooftop to get such a good view of the horizon.)

[+Red90]

I have a 60Cx. After it holds 35 for a few minutes and gets the "Ds", it then shows the satelite in the correct location.

[+TeamCNJC]

OK - here's my theory on the "x" series, WAAS corrections, and why sometimes it's in its old position, sometimes it's in it's new... Any input is welcomed.

 

1) WAAS SVs are not part of the "standard" GPS almanac. Doing hard resets to enable a new almanac will not make PRN 35 show up in the "west" as opposed to where it used to be in the "east." Save yourself the time of reloading waypoints and resetting preferences.

 

2) Since PRN 35 has moved, the "x" SiRF chip can't verify that the signal is "correct," since the SV isn't where it's supposed to be. Therefore, it ignores what it sees from PRN 35, including the WAAS almanac.

 

3) Since the SiRF chip doesn't have any expectations from the new WAAS SVs, or the older WAAS SVs are where they are supposed to be, it obtains information from them, including the WAAS almanac.

 

4) Once the WAAS almanac is obtained, the position of PRN 35 is updated, and you can then see it in the "west" where it's supposed to be. The SiRF chip is then happy receiving and utilizing signals and corrections from PRN 35.

 

5) If the unit is turned off, it the SiRF chip will revert back to expecting PRN 35 in the "east," and without a secondary WAAS lock, you won't be able to repeat the experience of PRN 35 offering correction.

 

6) If the firmware is updated with a new "baseline" WAAS almanac, showing PRN 35 in it's new position, we won't have this issue anymore. Also, if the firmware is updated to update the WAAS almanac despite not being able to find a WAAS SV in it's "proper" position, we won't have this problem anymore.

 

This theory explains why PRN 35 can "jump" around on an x-series, and why you can get corrections one day, and not another day. In any event, WAAS behavior in the Garmin implementation of SiRF is not what we're expecting, based on our collective experience with non-SiRF Garmins or non-Garmin SiRFs...

 

Thoughts?

[+GPSlug]

(TeamCNJC has snuck in a post while I was typing and being interrupted, but this kind of addresses that too.)

 

35 is still winkin and blinkin in the ESE out here west of Houston. Haven't seen any other WAAS birds flying around.

 

Still no D's with 35 but with a 8'-9' EPE it surely is sending out some kind of corrections. But, I'm get an 8'-9' EPE with WAAS disabled??? Go figure. Actual accuracy is that, or better, and sometimes worse.

 

Well, #35 is currently located at 142 degrees west; therefore, #35 is located SW of Houston and not ESE. Apparently, your GPSr is searching for #35 at its old position which was ESE of Houston. My 60CSx is also searching for #35 in the SE direction from here in Indianapolis. Hopefully, Garmin will fix this problem with the next firmware update.

 

Yep, I'm aware of that. I did a hard reset of the 60cx and it still shows up in the ESE. When I went to northern Oklahoma, it even moved down a little on the horizon. There was one day about a month ago where it showed up in the SW and I even got D's on that day. But, never since.

So it must have a default WAAS almanac hard-coded in.

 

Either way, it should be irrelevant where in the sky it thinks 35 is. The only relevant factors for searching are PRN and Doppler frequency offset. For the WAAS GEO's the Doppler will always be zero(ish) no matter what the longitude. Even when 35 was moving it would still have been close enough to consider it to be zero.

 

Anyway, my point is that 35's new placement shouldn't be the reason some x's are having trouble getting it if it still has decent elevation. It must be more related to WAAS tracking in general.

[+GPSlug]

I can't remember, have Southern California users had any problems with 47?

[+Red90]

Either way, it should be irrelevant where in the sky it thinks 35 is. The only relevant factors for searching are PRN and Doppler frequency offset. For the WAAS GEO's the Doppler will always be zero(ish) no matter what the longitude. Even when 35 was moving it would still have been close enough to consider it to be zero.

 

Anyway, my point is that 35's new placement shouldn't be the reason some x's are having trouble getting it if it still has decent elevation. It must be more related to WAAS tracking in general.

 

Except, what I think it does, is that after you location is determined (seconds with the 60Cx), it then assumes that only certain WAAS birds are visible at that location and ONLY searches for the ones that it should be able to see. It NEVER tries to search for the new birds even after the WAAS almanac is loaded.

 

The STRANGE thing is that 35 shows as a weak signal until the WAAS almanac is loaded. After it is loaded, the signal shows strong (normal). That seems very weird.

[planewood]

 

6) If the firmware is updated with a new "baseline" WAAS almanac, showing PRN 35 in it's new position, we won't have this issue anymore. Also, if the firmware is updated to update the WAAS almanac despite not being able to find a WAAS SV in it's "proper" position, we won't have this problem anymore.

 

Thoughts?

 

So, is 6) above, regarding a baseline WAAS almanac in firmware, fact, or theory?

 

If fact, then wasn't that a rather stupid thing for Garmin to do? And, since issuing a firmware update for an updated 'baseline' almanac should be a fairly simple thing to do, why hasn't Garmin done such before now?? Could it be that their waiting for all the WAAS birds to settle down at their permanent roost?

 

Don't the WAAS birds continuously transmitt their almanac data?

[+TeamCNJC]

So, is 6) above, regarding a baseline WAAS almanac in firmware, fact, or theory?

 

 

It's a theoretical fact.

 

OK - based on the behavior of these units, when you do a hard reset, all data is gone. But if you select a "new location," you'll get a constellation that moves around a bit until the unit finds itself. If there were no baseline almanac, you wouldn't see anything on the satellite screen until a full almanac had been downloaded. So programming in a baseline almanac into the firmware, which is updated periodically, makes cold starts faster. I'm positive that Magellan units have this feature. I don't think that it's stupid, as there's really no downside to doing this, as the new almanac data will quickly overwrite the older data from the firmware.

 

My guess here is that this way of speeding up a cold start doesn't jive with SiRF, and is simply a growing pain. There's probably some sort of error detection/correction that's preventing PRN 35 information from being used, except that the error "detection" prevents the data from being downloaded that provides the correction.

 

Like I said earlier, it's my theory. I'm just trying to understand why my cool new toy won't use correction data at home (W93), but worked fine when I was in NYC and in Europe...

[+PDOP's]

51 went away again, came back unhealthy, and is now gone again; with maybe some other events in between I didn't see.

It's back. Nice strong signal too. Looking forward to this fall when we'll be able to use the ranging signals from these two.

 

[+Geo Knot]

So, is 6) above, regarding a baseline WAAS almanac in firmware, fact, or theory?

 

 

It's a theoretical fact.

 

OK - based on the behavior of these units, when you do a hard reset, all data is gone. But if you select a "new location," you'll get a constellation that moves around a bit until the unit finds itself. If there were no baseline almanac, you wouldn't see anything on the satellite screen until a full almanac had been downloaded. So programming in a baseline almanac into the firmware, which is updated periodically, makes cold starts faster. I'm positive that Magellan units have this feature. I don't think that it's stupid, as there's really no downside to doing this, as the new almanac data will quickly overwrite the older data from the firmware.

 

My guess here is that this way of speeding up a cold start doesn't jive with SiRF, and is simply a growing pain. There's probably some sort of error detection/correction that's preventing PRN 35 information from being used, except that the error "detection" prevents the data from being downloaded that provides the correction.

 

Like I said earlier, it's my theory. I'm just trying to understand why my cool new toy won't use correction data at home (W93), but worked fine when I was in NYC and in Europe...

 

I think you are correct. It appears that many with the cx or cxs in the central portion of the US/CA are usually only able to receive signals from WAAS 35. For some reason these units are not getting their almanacs updated from 35 and therefor never get a lock on it. The exception appears to be persons that can also receive from a different WAAS satellite and obtain a good almanac allowing then to get info to lock on 35. Hopefully when all the satellites have been tested and stabilized, the cx units in the central portions of NA will be able to utilize the WAAS corrections.

 

Also, I found this info on WAAS GEO status

 

-BW

[Twilight Error]

#51 has been showing a full length hollow bar for the past week up here in New England, with occasional hollow bars on 35 and 48. The signals drop under heavy tree cover, but I'm only using a 76CS. When my Gilsson shows up, I expect that'll improve somewhat. Number 33 shows up often, and I do get a solid bar, but never more than half strength.

[Guyute1210]

I'm in western PA, and I only ever see 35, it never looks for any other one. I have a 60CS...anyone know why i never see any other WAAS birds?

[+PDOP's]

Have you upgraded your firmware to version 4.10?

 

Changes made from version 4.00 to 4.10:

 

* Adds support for Topo Great Britain maps.

* Correctly handles apostrophes and prefixes when displaying European city names and streets.

* Fixes occasional shutdown on highway page.

* Uses updated search process for WAAS and EGNOS satellites.

* Presents only relevant cities as choices given during address or intersection searches.

* Preserves stopwatch lap distance if user goes off of the stopwatch page.

* Corrects profile plot for tracks and routes that cross the Prime Meridian.

* Prevents long idle times during power save GPS mode.

* Sounds anchor drag alarm until reset by the user rather than sounding just a single tone.

* Shows proper units on the map page when reviewing depth contours on the map page.

* Applies map datum only to the Location (selected) field and not to the Location (lat/lon) field.

[indygpser]

* Uses updated search process for WAAS and EGNOS satellites.

 

Shouldn't Garmin be doing this for the 60 and 76 C(S)x units? I would think so, IMO.

Edited May 12, 2006 by indygpser

[+Red90]

The problem is (I suspect) is that the search process is built into the Sirf chipset and thus is more difficult to get changed as they need to get Sirf to do the reprogramming.