Waypoint accuracy
Submitted: Monday, Apr 30, 2007 at 12:17
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greydemon
Hi all, I have been loading some
Pilbara waypoints into my GPS software prior to a trip in July. Looking at any particular
junction there is a noticeable difference between the
track junction shown on my software (just the Mapsource software that came with the eTrek GPS), the data from the Hema map, and the data from the Exploroz trek notes. The difference is over 2 kms in some cases, an appreciable error. The Hema map does miss the last digit and states that the accuracy is limited but I expected better than 2kms.
Can I safely assume that the Exploroz waypoint data was provided by an Exploroz user actually there on the ground with GPS in hand and therefore far more reliable than the other two sources?
Nick
Reply By: ExplorOz Team - David - Monday, Apr 30, 2007 at 13:18
Monday, Apr 30, 2007 at 13:18
Yes it was recorded by me - along with over 70% of the other waypoints available in ExplorOz treknotes. If they differ please let us know so that we can adjust them however these were updated and tested on our last trip in the area a couple of years back - aside from some possible minor road re-alignment they should be 100%.
AnswerID:
236840
Follow Up By: greydemon - Monday, Apr 30, 2007 at 15:04
Monday, Apr 30, 2007 at 15:04
Thanks David, I am perfectly happy now and will go with the exploroz waypoints - I have just purchased the credits to download them. Of course, if I get lost it is now completely your fault and nothing to do with any failing on my part! 8-)
Knowing that you have been to 70% of the
places marked on the trek notes does not make me feel any better about my job. Anyone want waypoints for the coffee machine or photocopier? Perhaps for the car
park - that is at least out of doors ?
FollowupID:
497906
Follow Up By: SA_Patrol - Monday, Apr 30, 2007 at 19:15
Monday, Apr 30, 2007 at 19:15
Hi greydemon, I wouldn't trust the Base maps that comes with the Garmin units. you could download Tracks4Australia which will give you tracks in the area. You also must make sure your using the same Datum as what is listed. Most maps are at WGS 84 .
Grid is also important. I also set my GPS to Lat/Lon hddd' mm.mmm others have it at hddd'mm'ss.s and hddd.ddddd.
Make sure you have the degrees and dot in the right place.
FollowupID:
497956
Follow Up By: greydemon - Wednesday, May 02, 2007 at 01:14
Wednesday, May 02, 2007 at 01:14
Thanks SA Patrol. I am a complete novice at this. Evidence: I bought credits to download the waypoints from here without realising that the download only works on Oziexplorer ... which I do not have. Fooled by the phrase "download these wayponts to your mapping software" ah
well, $10 contribution to running this site which is a bargain!
I have followed your advice and downloaded Tracks4Australia, updating from Mapsource version 2 up to about version 6 in one hit. I now have a file containing a large number of .img files. Can you guide me on the next step - how do I get Mapsoure to use these files ? I am searching for the user manual which presumably came with the software but haven't found it yet. Up until now I have only used my GPS for a few local hikes and geocaching and the old mapsource was adequate for that without having to bother much about whistles and bells.
Thanks
Nick
FollowupID:
498328
Follow Up By: greydemon - Wednesday, May 02, 2007 at 01:21
Wednesday, May 02, 2007 at 01:21
OK SA_Patrol, cancel that - I have worked it out. Thanks
FollowupID:
498329
Reply By: Sand Man (SA) - Monday, Apr 30, 2007 at 18:03
Monday, Apr 30, 2007 at 18:03
Nick,
Have you set your GPS with the correct Datum to match the Mapsource software.
If you are using an incorrect Datum, this will produce an error.
Not being a Garmin/Mapsource user I don't know what is the correct one to use, but the Garmin Website should have this reference.
AnswerID:
236899
Reply By: SA_Patrol - Wednesday, May 02, 2007 at 08:26
Wednesday, May 02, 2007 at 08:26
Hi greydemon, if you go into the GCA site you could ask for a copy of Shonkymaps for your Garmin they are better than the T4A pro version and it's free, if your in WA you could ask everlasting for a copy.
AnswerID:
237345