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Author Topic: Track Record Log Method Dakota 20  (Read 8256 times)

Yenalom

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Track Record Log Method Dakota 20
« on: May 13, 2011, 04:23:31 AM »
There are 3 choices on how to record track logs on my Dakota 20:
        -Distance
        -Time
        -Auto

If I select distance, the shortest distance I can input is 0.01 miles or about 53 feet. Is there any way of entering a smaller amount say something like 0.003 miles? The input screen has enough places but I cannot enter anything beyond the hundredths place.

All help is appreciated.

Bob M 

Boyd

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Re: Track Record Log Method Dakota 20
« Reply #1 on: May 13, 2011, 04:36:33 AM »
I think "it is what it is". If you want the maximum amount of track data you should set it to record a point every second. That is the speed at which the gps updates its position so you will get everything. Of course, you will reach the 10,000 point tracklog limit in a little under 3 hours though.

What happens if you set your units to metric? Will it let you record a point every .01 kilometers? That would be 10 meters or about 33 feet.

IF you could set it for .003 miles (~15 feet) like you want, I think you'd get a lot of questionable data because the GPS just isn't that accurate, especially when it's moving.
« Last Edit: May 13, 2011, 04:43:49 AM by Boyd »

Seldom

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Re: Track Record Log Method Dakota 20
« Reply #2 on: May 13, 2011, 05:27:12 AM »
With my OR300 (think DKs are suppose to be the same) I can set the record units to yards and then set the record by distance to 0001.00 yards.  Can't move the decimal point though.  I don't recommend this setting though because it will generate serious spider webbing when the unit is on but not moving. and the added accuracy isn't that helpful in map making.  I suggest 10 yards or meters as a good record by distance setting.

Set up Units, Select Distance, Select Yards.
Setup Tracks, Select Interval, type 0s until you get to the decimal position you want.

Yenalom

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Re: Track Record Log Method Dakota 20
« Reply #3 on: May 13, 2011, 06:34:29 AM »
Thanks for the replies.

 I never thought of changing the measurement to metric. I just did and I was able to enter 0.01 km (about 33 feet as Boyd mentioned).

 I have been using every 10 seconds on both the Dakota and my Magellan when I hike. I pick up a track point somewhere between  15 to 25 feet with the 10 second interval. I wanted to set one of the machines to a fixed interval of about 20 feet so that I could compare the tracks based on a fixed time and a fixed distance. Unfortunately neither the Magellan nor the Dakota go below 50 feet.

 I do believe that some older Garmin units could go down to about 5 feet. The Dakota is the first Garmin I have owned. with my older Magellan I could only go down to 50 feet and could not select by time. My track length was consistently about 10% shorter than a friend using a Garmin. When I obtained a copies of his tracks, the big difference  between them was my interval of 50 feet and his of 5 feet. Whether the 10% longer track from the Garmin is real or due to the spider track phenomena is a good question.     

   

Seldom

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Re: Track Record Log Method Dakota 20
« Reply #4 on: May 13, 2011, 08:34:08 AM »
See my message above.  On my OR, I was able to set the interval to 1 yard.  Not a realistic setting, but possible.

Re: Spider tracks.  If you can set your DK to 1 yard and let it sit stationary where it can get a signal you will generate some great spiderwebs.

maps4gps

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Re: Track Record Log Method Dakota 20
« Reply #5 on: May 13, 2011, 08:34:55 AM »
There have been may posts on various forums about tracks being overly long compared to other sources (printed maps, trail guides, etc.).  True for both horizontal and vertical distances.

Boyd

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Re: Track Record Log Method Dakota 20
« Reply #6 on: May 13, 2011, 09:53:00 AM »
I did some comparisons between my Oregon 400t and GPSMap 60csx awhile ago and had both units set to record a point every second. The 60csx seems much more prone to "wandering" than the Oregon (which has the same chipset as your Dakota). I walked over the exact same narrow trails on my property multiple times with the Oregon on one hip and the 60csx on the other.

You can see that the Oregon track points are clustered together much more tightly than the 60csx. To get a sense of the scale, each of the dots in this screen shot are one second apart, which might be the equivalent of about a meter at walking speed (?).


Yenalom

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Re: Track Record Log Method Dakota 20
« Reply #7 on: May 13, 2011, 02:52:08 PM »
The previous messages got me thinking.

 Wednesday I was hiking. From a few minutes to noon until about 12:25 we stopped for lunch.  I had 2 gps's attached to my pack, a Magellan Triton 500 and a Garmin Dakota 20. Both were picking up track points every 10 seconds.

I decided to look closely at the trackpoints. I then realized I no longer had the track from the Garmin(I had deleted the file because the battery went dead (my fault) before the hike was completed).

In any case, I did plot the trackpoints for the Triton. They are shown in the attachment Spider Plot 1.jpg.  This shows the track with a UTM grid.

Honestly, I was surprised there was so much false movement in the 25 minutes. Total measured distance moved was about 0.12 miles. total elevation change was about 50 feet!

The next time I am out, I will capture the points from both the Dakota and the Triton  so that I can compare them.

Bob M

Boyd

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Re: Track Record Log Method Dakota 20
« Reply #8 on: May 13, 2011, 06:36:48 PM »
I think the Tritons use the same SiRF chips as the 60csx - I have a Triton 1500 that I rarely use myself.

Yenalom

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Re: Track Record Log Method Dakota 20
« Reply #9 on: May 14, 2011, 05:57:17 AM »
I  realized this morning that I had deleted the Garmin track from my computer but probably still had it on the GPS itself. I checked and there it was.

Attached is Spider Plot 2.jpg which shows both the Triton and Dakota spider plot for roughly the same time period (155 points for the Triton, 163 for the Dakota. Clearly the Dakota is superior. It probably makes little practical difference. The Triton will  overstate walking time, distance and elevation gain and understate waiting time by some small amount. Practically this makes little difference.

Some history, my first GPS was a Magellan 315 about 15 years ago, along the way I then upgraded to a SPORTRAK Map and then to a SPORTRAK Color. When the Triton series came out, I considered upgrading. Luckily, I did not and I avoided all the initial Triton problems. About 2 or 3 years ago when I heard the it was easy to install custom raster maps on the Triton, I bought the 500. I then built custom maps for hiking trails in the NYC metropolitan area. I was happy with them and impressed other hikers with them. I then bought a Triton 1100 primarily to run OZICE on it. Frankly, i was not happy with OZICE. I then used both. I did prefer the 500 over the 1100 because I did not like the hybrid touch/button system.  By this time, Garmin came out with their custom map system. I then made kmz files for Garmin units. Several people bought new Garmin units and loaded my files.Not owning a Garmin, I was unable to help them with their problems. I finally picked up the Dakota on e-bay and sold my Triton 1100.

My impressions of the Dakota are positive. it is much more intuitive than the Triton line. The 100% touch screen system makes more sense than the hybrid Triton system. However, the Magellan system for custom maps beats the Garmin system hands down. As you know there is no limit on custom maps for the Magellan line  and individual maps can be enabled separately. If or when Garmin will do something like that is questionable.

Bob M
« Last Edit: May 14, 2011, 08:37:53 AM by Indrid Cold »

 

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