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Posts posted by TeamCNJC

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



    It's a theoretical fact. :ph34r:


    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...

  2. 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...



  3. Geognerd is 100% correct - I've used multiple models from different manufacturers in both the US and Europe. Getting a fix the first time takes a while (especially if you're on a moving train), both when you power up in Europe and when you get back to the US. Restarting or selecting a new location (depending on model) will speed up the first fix time.


    When I was using my Meridian Gold, I was able to change the basemap for US to Europe - I don't know if that's possible with the Explorist series or not...

  4. I wouldn't mind uploading it to just the SDmicro card, but not sure how to do that yet..... any help would be appreciated, or anyone else who has tryed this software and was successful would be nice to hear from you...



    When you "upload" to your x-branded Garmin, you're actually just writing the file to the SD card - there's no internal memory for user-initiated maps. I don't think that SendMap works with an SD card, but MapSource does - simply put your microSD card in a reader and you can write directly to the card.


    Try this - take an extra card and put it in your GPSr (if you've upgraded, you've got the original one floating around), then upload the custom map. If it doesn't work, you can just remove the card from the unit and format it with an external reader to returned it to baseline.

  5. Actually, on a side note I use a Lawrence, and my caching buddies use Garmin, I have noticed every single time, I had a better accuracy, I have never had my unit off by 4 meters on any cache so far (I have done about 60 of them).


    food for thought.


    Interesting observation - I wonder how many caches were placed with a Lowrence? I'm guessing the vast majority were placed with a Garmin or Magellan, and I would doubt any signficant difference between placing and finding a cache, at least in terms of GPSr accuracy. Then again, there's averaging...



  6. Just to add my few cents to this thread...


    I've been a loyal Magellan owner since 2002 - started with a Garmin Venture, bought a MeriGold as an upgrade. Like the interface, the reception was great, mapping was just "OK." Won a SporTrak Color in a Magellan contest, but the screen and the slow interface made it impractical to do anything but load a map once and let it sit in the car. Adding autorouting via a software/firmware update was a real plus, then the disappointment sent in... I don't have anything to add that hasn't been mentioned above.


    Actually, I do. My Gold is on it's second screen, and is showng blue spots yet again...


    I'll be upgrading - my decision is between the 60CSx and the 76CSx.

  7. YES - I did this with my STColor, but it's all for naught if you're using DirectRoute maps. The DR maps invoke a different "lawyer" screen. I believe that there are people who successfully changed that screen, but not with MyMeridian.


    You need to modify the MyMeridian.ini file to recognize the ever-so-slight differences between the Meridian-series and the ST-series firmware. My .ini file looks like this:




    ;Magellan GPS types supported

    ;  0 = Meridian Gold, Platinum, or Marine

    ;  1 = Map330 series

    ;  2 = Meridian Green (firmware split at V3.12 (April 17, 2002)




    Message=Craig Doerrmann\nAddress1\nAddress2\nPhone\nEmail\nThank you.










    English=All data is provided


  8. Is that a separate setting on that model?  On mine I have "mode" with chose of battery saver, normal, and WAAS so it's impossible to set wrong.

    Yes. It's a separate setting in the eTrex line. I wasn't aware that they combined the settings in the Geko.

  9. 1) Meridian Gold w/256mB SD card, SporTrak Color, DirectRoute software


    2) Palm Tungsten T (GPXSpinner and iSilo)


    3) I'm eyeing the 60cs, but it would be hard to change brands with the current level of investment (software, cradle in boat, cables in car, etc.) Would have to come down in price significantly.

  10. Assuming you can see more then 10 sats.


    Actually, if you're only receiving corrections for 4 sats, you'll only be calculating a position based on those 4 sats, no matter how many sats are visible. That implemention of WAAS seems to be particular to Garmin units, and may have been corrected in later firmware versions. There's also a concern that Magellan units may continue to use "stale" WAAS corrections, so it's unclear if any manufacturer has figured out WAAS completely.


    I just have to ask if you have a source for that


    There's a lot of good WAAS information at gpsinformation.net. If you don't agree with them, please don't flame the messenger. :rolleyes:

  11. I was wanting some second opinions.

    I'd have to agree with you - I'm not very impressed, but the difference between the STColor and non-color units is impressive. You may not know what you're getting until you miss it. I just got DirectRoute, which seems to use color better than previous maps. Make sure you're running the latest firmware (5.01), too.

  12. Yeah, I just picked up on that. It looks like we'll get one .img file with DirectRoute information on it, which will allow autorouting, but we'll need to switch to a different .img map to get topo data. Not a big problem with my new 256MB SD card in my MeriGold icon_biggrin.gif, but what about a unit with fixed memory, like the SporTrak series? I'm guessing that the new firmware will allow detail map switching (the current firmware does now, but I haven't figured out how to upload map files with different names).




    ... Two roads diverged in a wood, and I--

    I took off through the thorns, chest high, ...

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