Extended Ephemeris CBEE

[redrock3]

I have checked several XL and XXL models updated through Home. Why do some ephem folders have the CBEE (extended ephemeris) file and some do not? Some also have the long term orbit LTO file but not all.

 

[dhn]

I think it has to do with which specific model and how long since the user got an updated quickgpsfix file using Home to 'update my unit'.

Frequently, when a user posts here problems getting a gps fix, the first suggestion is to delete anything in the ephem folder on the unit and, as well, any sub folders found here:

c:\documents and settings\yourname\my documents\TomTom\Home\Downloads\Complete\ephemeris\

and then connect to Home to get a new file.

 

[canderson]

We have recently heard that the cbee.cbee data is "calculated" ephemeris data. Well, isn't it ALL calculated unless it's a current almanac dump from one of the satellites? The LTO is only a projection of where things are expected to be.

While interesting, that bit of news from another source still doesn't help us understand these files, either. The cbee.cbee files didn't used to appear at all. They began to appear on some devices just AFTER the 9.400 code release. Seems all with 9.430 code now have these files.

Will be interesting to see what others may decipher. The file is very specific to the Broadcom chip that TomTom and others are using (it is showing up on other non-TomTom devices as well) and is a recent bit of data that is being provided by or for Broadcom. I'm guessing it's some sort of new 'prepackaged' ephemeris file that requires less computation than trying to use the lto data.

 

[redrock3]

Just an update. I acquired an XL 4ET0.002.03 today (newer black face model). Had 875 maps and a 9.061 navcore. (I paid $5.83 for it from the Bay.) But I looked at the ttgo.BIF file which showed it had been connected to something on June 13 which I thought was weird with the older Navcore. I connected it to Home but declined the offered update to 9.43 (that was all that was offered.) I then closed home and looked at the system files. I found an ephem file with the CBEE dated today! Yet Tomtom Home never asked nor indicated it installed anything. I went ahead and updated it to the 9.40 Navcore from my PC and not through Home. I am not sure what I think of files being installed without a prompt or an option to decline. Sort of a stealth install. The maps are correct and keyed to the unit.

 

[redrock3]

Just an update to the update, without any prompt at all, I saw where Home today installed a 192k CBEE file to a 350XL unit with a 9.43 Navcore.

 

[canderson]

Now that's strange. (I think that XL could actually be the XL335SE, BTW - the similarities are considerable).

You didn't accept any update from Home, but you found the device had a new cbee.cbee anyway?!?

 

[redrock3]

It had the current Navcore and Home did not prompt to install any updates at all. Yet after I disconnected, I looked at the files because I have been following this issue some, I saw a CBEE file dated (today) in the ephem folder. Later, it did prompt to install a mapshare update.

 

[canderson]

Thanks for that information. I will keep very careful track of this myself, now. Given recent history with ephemeris data issues, it would be a very bad thing to discover that ephemeris data is being 'pushed' to Nav2 devices. Or perhaps they are doing this intentionally just for a little while to assure they have flushed out for all users the bad ephemeris data that was being sent on 30 June?

 

[dhn]

But the gps chipset for that model is NOT a SrfIII so it wasn't affected by the issue, was it?

 

[canderson]

No, it wasn't. SiRF vs. Broadcomm. I'm just wondering if TomTom got paranoid.

And in spite of redrock3's presentation of the details, something still seems wrong about this. As bad as Home can behave at times, I have NEVER seen it NOT inform a user about a pending download and installation, if for no other reason than to avoid the disaster of disconnecting during a transfer.

 

[redrock3]

XL 350 - 2GB TTS

units serial starts with a GK.

I had recently purchased this unit (looked new) and it struggled to get a sat lock. I then checked the files and did not see an ephem folder. I connected to Home but declined to log in on the acct, which is linked to another unit I have. I just wanted any basic updates that Home would offer in default mode. The newest Navcore was already installed. It prompted me for nothing. I checked the unit after and found that ephem folder and file because it has happened to me once before on another unit. I don't have pirated maps and I have no real concerns about what files are put on my unit as long as it helps get where I am going rather than somehow track where I have been ! I connected again and got a tiny mapshare update and that was the end of it.

 

[Andy_P]

Interesting... I have a friend on another (non TomTom) forum who had rthe "off track" issue on a Go300.
He too said he didn't have an "ephem" folder on his device when I told him to delete it.. I'll see what happens when he connects to Home....

 

[canderson]

I'll see what happens when he connects to Home....

... and before he accepts any updates!

 

[redrock3]

Without a doubt it pushed this file on an xl 340 yesterday. I brought another used one off eBay. Had 845 series maps and a 9.061 navcore. There was no ephem folder. I updated to the 9.43 navcore and that was the only prompt. I checked after the update and a ephem folder and a CBEE file were sho nuff there.