Recording Track Log vs Sonar Files

I'm getting re-energizing my efforts to make my own maps and have a few questions. I'm running a (2011 or 2012) Humminbird 898c HD SI and Autochart (not Autochart Pro). It's very unlikely that I'm going to upgrade to Onyx or Autochart Pro.

The "Autochart Getting Started Guide" states this, "The track log will result in smaller files than sonar logs, but will not include data to get bottom hardness. To get bottom hardness you must record sonar data."
1) I do not believe that Autochart has bottom hardness capability, i.e. only Autochart Pro does. Should I just record the track log? Will recording just the track log produce depth maps?
2) How much smaller are track logs vs sonar data, i.e. bits, bytes, etc.? If it's incidental, I'll just record sonar data. If it's significant, and I get the info that I need from the track log, then I'll record the track log. Just trying to save space on my Zero Line Map Card.
3) I recorded sonar logs for a couple of hour on an SDHC card, then forgot to "stop recording" and "save" the information before I shut down my unit. Will this corrupt the data, or will I be able to produce an initial map from this recording?

Appreciate any answers that anybody can provide.

Hey Jeff,
1) My own limited experience and personal preference is Sonar over Track. I'm looking for the best possible detail for my maps as there are no charts for the lake I fish. My learning is that greater detail is obtained from the sonar recordings. I'm running pro and the hardness is nice but, not as critical as knowing the depth.

2) I suspect track logs are smaller than sonar but someone else will have to tell you as I don't record tracks. My sonar files from a day on the lake (6-8hrs) range from 600MB to just over 800MB. (Roughly 1MB/hr) That's times 3 as my RECORD folder will have 3 files per recording. I think B001 is depth and B002 & B003 are side imaging. I'm out in the middle of nowhere for 4 days so I have an extra SD card for recording just in case. That said, my ZeroLine Card is 32GB (Probably the same for regular autochart) and with my maps on it I have 17GB available. That's 17,000/3= over 5600hrs of recording room. Your mileage may vary.

3) I'd say: "If you've got any data, that's better than none." I really like the editing feature in Autochart. You can review and obliterate anything that's suspect. (I forgot to shut off my unit when I pulled up and was able to negate about 50 yards of pavement from my logs) If you still have the recording, it's worth having a look at to see what can be salvaged if anything looks wonky.
Have fun!

TheGooly,

Thanks for coming up on the net with the reply. I've got some issue as 15.3 GB of space on my ZeroLine Card are used up after loading about 24 hours of sonar readings. I saw the presentation on deleting maps, and I'll follow that so that I don't delete one of the "wrong" files.

v/r,

Jeff

P.S. If anybody else has any input, I'd appreciate you weighing in.

Don't delete your maps. You need to save your sonar recordings off of your zerolines sd card, and copy them onto your computer. Your zerolines sd card does not need to be used to save sonar recordings or tracks. I have two card slots in my unit, so I usually save my sonar recordings to a blank sd card, rather than the zerolines sd card.
Either way though, when I get back, I copy my RECORD folder from the sd card over to my computer, and then delete it from my sd card.
Just like you would with digital pictures from a camera.

You will not be able to store all of your recordings or track files on an sd card, or you would run out of room on any sd card.

1.) I would use sonar recording also. The point intervals are a little closer together versus .ht hummingbird tracks. Sonar recordings do take up a lot more storage space though. You DO need to remember to save the sonar recording, before turning off the unit though. But you should do that with track files also.
I actually use both though, I make sonar recordings and plan on using them, but I also save my track file at the end. That way, if something were corrupt with one of my recordings, I'd still have something useable by also saving the track file.

3.) You might have some useable data (.son files) inside folders inside the RECORD folder, but you likely won't be able to import the .dat file. That was likely not saved if you shut off your unit before you stopped the recording.