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Wild sats lately


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I have noticed that I have been seeing very bad reception on my GPS receivers lately. At first I simply thought it was the device but lately I have been carrying two or three. All seem to be acting irratic though to different degrees. I carry two Magellans and lately I carry my PDA with a bt Pharos. Never to I get convergence.

 

I can stand in one place, under clear sky and watch my GPS drift over 100 feet!

 

For the most part, I have ruled out access to the sky. I insure I have fresh batteries. At this point, I have to believe it is coming from the sats.

I live in North Georgia though last week I was in the Shanandoa Valley and it was no better.

 

Possibly we are in a time of increased sun-spot activity.

Is anyone else seeing this?

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I'm so reluctant to admit this, because I fear it will start a firestorm of Magellan-haters, but yes, I have noticed it.

 

I have an Magellan Explorist 210, but I use it differently than most. Rather than using the compass w/ feet to destination, I use the navigational page that shows the cache (looks like a treasure chest). I just walk until it looks like I'm standing on the chest (the triangle is over the chest). That's the area I look in. I've never had really good luck using the compass portion and this is only MY opinion.

 

That being said, I was caching over the weekend and noticed that the unit was sluggish in reflecting my movements. Then, it'd catch up and the triangle would 'jump' to my location. This is usually not the case. I'd been caching earlier in the week and everything was fine. Not until Saturday & Sunday did I notice some unusual activity.

 

I thought to myself "Gee? Sun Flares?!" Funny that you thought the same!

 

Also, I have a Garmin Nuvi for the car and this weekend it was taking much longer for it to acquire satellite reception. Normally, it acquires it in about 15-20 seconds and it was taking a few minutes.

 

P.S. I'm in Indiana though and not close to you.

Edited by Jenischmeni
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Old Sol has been very quiet recently, as we are at solar minimum. No major outbursts, flares, spots etc. I'm an avid amateur astronomer and solar observer, and I'm waiting for more solar action! On the other hand, earth has intersected a light solar wind stream (chance of aurora for Canada and Alaska) which could have some effect on the satellites.

 

Current solar conditions and events are reported at www.spaceweather.com.

 

Cheers,

 

- Craig

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Actually the solar activity has been quite for the last few days, but it has picked up right now. Check it here: http://www.sec.noaa.gov/rt_plots/kp_3d.html

 

Yes two WAAS sat have been decomissioned but there are still 2 active which both cover all of the US, and you only need data from one.

 

Haven't had my GPS on today so I haven't seen the problem.

 

By the way I was getting 51 and 48 just fine yesterday with great accuracy. I don't think there is any problems there.

Edited by EraSeek
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For what it's worth...I fly for the military out in the Pac. Northwest. We flew a lot of training flights most of last week, all of last weekend, and today. Nothing unusual and there were no Notices to Airmen in regard to any GPS anomolies...if someone sneezes at GPS central they let us know.

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...I have an Magellan Explorist 210, but I use it differently than most. Rather than using the compass w/ feet to destination, I use the navigational page that shows the cache (looks like a treasure chest). I just walk until it looks like I'm standing on the chest (the triangle is over the chest). That's the area I look in. I've never had really good luck using the compass portion and this is only MY opinion...

If your Magellan has a satellite page that shows your current position, use that page to get you to ground zero. The coords go up numerically when heading north and west; so, it helps to know your north so you can move accordingly. This technique compensates very well for not having an electronic compass.

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It's funny because I recently hid a cache in an area that is very wide open with little tree cover and had complaints about coords being 50-100 ft. off. But one finder thought I was spot on. So I went back last weekend and this time I got the "complainers" coords. So I guess it's something.....

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May I suggest that there are times when things will go funky, and people automatically think "government messing with thing, sunspots, screwed up unit" but in fact it may simply be lousey sat configuration at the time and place of usage.

*

*

*

*

 

equals lousey configuration, but

 

* *

* *

* *

will get you a much better position and thing will seem to function better with less drift.

(Well, that didn't show correctly! The idea is that the sats need to be spread out for good solid fixes.)

Edited by EraSeek
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Just a quick comment - I have several notifications set up for geocaches in a few local areas of interest and I have been seen tons of logs stating that there has been a lot of "bounce" when trying to locate a cache! This is mostly occuring in the Northeast (NJ, PA, NY). I have not been looking in other areas of the country. My own GPS is back at Garmin for another reason so I don't have any first hand experience to offer. The last time that I used it (about two weeks ago), I noticed that it was in fact bouncing but I thought that was due to some of the other problems that I was having.

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Just a quick comment - I have several notifications set up for geocaches in a few local areas of interest and I have been seen tons of logs stating that there has been a lot of "bounce" when trying to locate a cache! This is mostly occuring in the Northeast (NJ, PA, NY). I have not been looking in other areas of the country. My own GPS is back at Garmin for another reason so I don't have any first hand experience to offer. The last time that I used it (about two weeks ago), I noticed that it was in fact bouncing but I thought that was due to some of the other problems that I was having.

 

I have a Garmin 60CSx and I was noticing that in the last few days it was taking a long time to acquire satellites. Plus, after I did get satellite reception, there did seem to be more bounce.

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I did some reading up on WAAS, and found this on Wikipedia:

 

The original two WAAS satellites, named Pacific Ocean Region (POR) and Atlantic Ocean Region-West (AOR-W), were leased space on Inmarsat III satellites. These satellites ceased WAAS transmissions on July 31, 2007. With the end of the Inmarsat lease approaching, two new satellites (Galaxy XV and Anik F1R) were launched in late 2005. Galaxy XV is a PanAmSat, and Anik F1R is a Telesat. As with the previous satellites, these are leased services under the FAA's Geostationary Satellite Communications Control Segment contract with Lockheed Martin for WAAS geostationary satellite leased services, who is contracted to provide up to three satellites through the year 2016.[7]

 

As of August, 2007, the new satellites are in an operational mode, mode, however
they are not yet full replacements.
While both new satellites transmit correction messages, their GPS-like signals are still being improved. Galaxy XV's ranging data is flagged as "Not Monitored" and Anik F1R's is flagged "Non Precision Approach." Both are expected to improve to "Precision Approach" during the second half of 2007.

 

http://en.wikipedia.org/wiki/WAAS#Space_Segment

 

Paul

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All that would explain a thing or two I've noticed as well.

 

This month, for the first time ever, I've been driving one of my regular routes between Montreal and Ottawa Canada to find my 60CSx completely loses lock...over a year of the same drive and never a hiccup. This month, speed goes to "0" for a short time for no explicable reason. Chalk it up to satellites!

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I did some reading up on WAAS, and found this on Wikipedia:

 

The original two WAAS satellites, named Pacific Ocean Region (POR) and Atlantic Ocean Region-West (AOR-W), were leased space on Inmarsat III satellites. These satellites ceased WAAS transmissions on July 31, 2007. With the end of the Inmarsat lease approaching, two new satellites (Galaxy XV and Anik F1R) were launched in late 2005. Galaxy XV is a PanAmSat, and Anik F1R is a Telesat. As with the previous satellites, these are leased services under the FAA's Geostationary Satellite Communications Control Segment contract with Lockheed Martin for WAAS geostationary satellite leased services, who is contracted to provide up to three satellites through the year 2016.[7]

 

As of August, 2007, the new satellites are in an operational mode, mode, however
they are not yet full replacements.
While both new satellites transmit correction messages, their GPS-like signals are still being improved. Galaxy XV's ranging data is flagged as "Not Monitored" and Anik F1R's is flagged "Non Precision Approach." Both are expected to improve to "Precision Approach" during the second half of 2007.

 

http://en.wikipedia.org/wiki/WAAS#Space_Segment

 

Paul

That won't really mean anything.

1. The ranging availability on the old ones was spotty at best since the move of 122(35).

2. Looking right now, 138(51) does have a usable range accuracy.

3. 138(51) and 135(48) are both out of test mode now, so their corrections are good (not that they weren't before).

4. The SiRF core doesn't range off the GEOs anyway.

 

With the higher power of the new GEOs, WAAS should be better than ever on a 60C(s)x.

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That won't really mean anything.

1. The ranging availability on the old ones was spotty at best since the move of 122(35).

2. Looking right now, 138(51) does have a usable range accuracy.

3. 138(51) and 135(48) are both out of test mode now, so their corrections are good (not that they weren't before).

4. The SiRF core doesn't range off the GEOs anyway.

 

With the higher power of the new GEOs, WAAS should be better than ever on a 60C(s)x.

 

How can we tell if 138 has useful range accuracy? Is there a way on the GPSr to see which satellites are accually being used?

 

I have an eTrex Vista HCX.

 

Thanks,

 

Paul

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In Sweden here, using a Tom Tom ONE and today when I switched it on it took over a minute to obtain a lock and I've noticed the past couple of weeks that it's been very slow to get reception and that just isn't "normal" for it! Usually it's very quick and we rarely have accuracy issues with it.

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How can we tell if 138 has useful range accuracy? Is there a way on the GPSr to see which satellites are accually being used?

 

I have an eTrex Vista HCX.

 

Thanks,

 

Paul

 

You can see real-time sat status here http://www.nstb.tc.faa.gov/RT_WaasSatelliteStatus.htm

The best way to tell if you unit is using a satelitte is if you have a filled in bar on your unit's sat status page. As GPSlug says, the sirf units do not use the WAAS sats for rangeing (as far as I know) but you will see the waas sat with a filled in bar, but no "d" correction. This is because they are only being used as WAAS sats and not ranging sats. This in my book is good because the WAAS sat ranging is never up to the true rangeing of a GPS sat anyway. Different units will do things differently. The Vista HCX has a different manufacturer's chip in it than the 60cx does.

Both 48 and 51 are out of test mode but 48 is at non-monitored for ranging and 51 is at non-precision for ranging. These both will improve to precision in the future. Want to know if you are getting good accurate ranging? It will have the WAAS "d" corrections on the sat bar. Then you know.

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