Comments for Ask the GPS Expert http://blog.expertgps.com/blog Expert answers to your questions about GPS, Mapping, GIS, and CAD Fri, 01 Jul 2011 16:52:09 +0000 hourly 1 http://wordpress.org/?v=3.3.1 Comment on How to Survey Your Property Lines using a GPS Receiver by Tom Arneson http://blog.expertgps.com/blog/2011/06/how-to-survey-your-property-lines-using-a-gps-receiver/comment-page-1/#comment-283 Tom Arneson Fri, 01 Jul 2011 16:52:09 +0000 http://blog.expertgps.com/blog/?p=413#comment-283 Dan, Bearings are most often assumed, based on one line of a section, being a cardinal direction. They are almost never "true". There are many versions of "North", geodetic, grid, astronomic, besides magnetic. Magnetic north varies over time (see: http://www.ngdc.noaa.gov/geomag/). To say that a navigation grade GPS should get one within a few feet of a corner is misleading, as at times it may be much worse. I see 50 feet at times, rare, but it happens. Tom Arneson, Minnesota licensed Land Surveyor N0 12682 Dan,

Bearings are most often assumed, based on one line of a section, being a cardinal direction. They are almost never “true”. There are many versions of “North”, geodetic, grid, astronomic, besides magnetic. Magnetic north varies over time (see: http://www.ngdc.noaa.gov/geomag/).

To say that a navigation grade GPS should get one within a few feet of a corner is misleading, as at times it may be much worse. I see 50 feet at times, rare, but it happens.

Tom Arneson, Minnesota licensed Land Surveyor N0 12682

]]> Comment on Creating custom map symbols and markers with ExpertGPS by Dan Foster http://blog.expertgps.com/blog/2008/12/creating-custom-map-symbols-and-markers-with-expertgps/comment-page-1/#comment-224 Dan Foster Wed, 01 Sep 2010 14:38:23 +0000 http://blog.expertgps.com/blog/?p=109#comment-224 You need to put your custom symbols folder somewhere on the Web so that ExpertGPS can grab the symbols when someone else opens one of your GPX files. You put the URL to this location in the first line of Readme.txt Because the NPS_Buildings symbols live at http://www.topografix.com/Symbols/NPS_Buildings The first line of that Readme.txt file is: http://www.topografix.com/Symbols/ You need to put your custom symbols folder somewhere on the Web so that ExpertGPS can grab the symbols when someone else opens one of your GPX files. You put the URL to this location in the first line of Readme.txt

Because the NPS_Buildings symbols live at
http://www.topografix.com/Symbols/NPS_Buildings

The first line of that Readme.txt file is:
http://www.topografix.com/Symbols/

]]> Comment on Mapping PLSS / TRS Coordinates in ExpertGPS Pro by Dan Foster http://blog.expertgps.com/blog/2008/10/mapping-plss-trs-coordinates-in-expertgps-pro/comment-page-1/#comment-223 Dan Foster Wed, 01 Sep 2010 14:32:47 +0000 http://blog.expertgps.com/blog/?p=68#comment-223 Unfortunately, the author of the PLSS/TRS component that ExpertGPS Pro uses will not be adding any new states or meridians. Unfortunately, the author of the PLSS/TRS component that ExpertGPS Pro uses will not be adding any new states or meridians.

]]> Comment on Mapping PLSS / TRS Coordinates in ExpertGPS Pro by Michael Lussier http://blog.expertgps.com/blog/2008/10/mapping-plss-trs-coordinates-in-expertgps-pro/comment-page-1/#comment-221 Michael Lussier Thu, 26 Aug 2010 17:56:52 +0000 http://blog.expertgps.com/blog/?p=68#comment-221 Any idea when Virginia maybe added ? Any idea when Virginia maybe added ?

]]> Comment on Creating custom map symbols and markers with ExpertGPS by Karl Hogard http://blog.expertgps.com/blog/2008/12/creating-custom-map-symbols-and-markers-with-expertgps/comment-page-1/#comment-50 Karl Hogard Tue, 10 Aug 2010 10:22:18 +0000 http://blog.expertgps.com/blog/?p=109#comment-50 I've got directed to the'creating map symbols... http://blog.expertgps.com/blog/2008/12/creating-custom-map-symbols-and-markers-with-expertgps/ page, but I do not know which URL to put into the 'NPS-Buildings', etc folders, as they only contain a thumbnails file. I’ve got directed to the’creating map symbols… http://blog.expertgps.com/blog/2008/12/creating-custom-map-symbols-and-markers-with-expertgps/ page, but I do not know which URL to put into the ‘NPS-Buildings’, etc folders, as they only contain a thumbnails file.

]]> Comment on US National Grid (USNG) Map Overlays and Grid Lines by Al Studt http://blog.expertgps.com/blog/2009/03/us-national-grid-usng-map-overlays-and-grid-lines/comment-page-1/#comment-99 Al Studt Wed, 30 Dec 2009 02:16:27 +0000 http://blog.expertgps.com/blog/?p=208#comment-99 Dan, here is a link to a USNG article: http://www.floridadisasterengineers.org/USNG_Files/FDE_posting1/USNG_GENERAL/Start_using_US-National-Grid.pdf Dan, here is a link to a USNG article: http://www.floridadisasterengineers.org/USNG_Files/FDE_posting1/USNG_GENERAL/Start_using_US-National-Grid.pdf

]]> Comment on Using a USB to Serial Adapter by Michael Rowell http://blog.expertgps.com/blog/2008/10/ask-the-gps-expert-using-a-usb-to-serial-adapter/comment-page-1/#comment-2 Michael Rowell Tue, 01 Sep 2009 19:03:14 +0000 http://blog.expertgps.com/blog/?p=4#comment-2 I have a Garman 76S, everything seems to work ok till I try to download from my GPS. Then it will turn off around a second after it starts. What can I do? I have a Garman 76S, everything seems to work ok till I try to download from my GPS. Then it will turn off around a second after it starts. What can I do?

]]> Comment on Mapping Legal Land Descriptions in ExpertGPS by Brandy G. http://blog.expertgps.com/blog/2008/11/mapping-legal-land-descriptions-in-expertgps/comment-page-1/#comment-39 Brandy G. Fri, 21 Aug 2009 16:10:33 +0000 http://blog.expertgps.com/blog/?p=87#comment-39 When can we expect the legal land description import to be available? When can we expect the legal land description import to be available?

]]> Comment on Geocaching Puzzle Caches: How to find the Orthocenter of a Triangle by Anthony http://blog.expertgps.com/blog/2009/03/geocaching-puzzle-caches-how-to-find-the-orthocenter-of-a-triangle/comment-page-1/#comment-101 Anthony Mon, 10 Aug 2009 19:55:47 +0000 http://blog.expertgps.com/blog/?p=220#comment-101 I'd like to set this up in my area, but to implement it, doesn't it have to be worked in reverse? In other words, hide the cache, get the coordinates, and then find a way to make 3 waypoints forming a triangle, with the orthocenter being the coordinates of the cache? To do so in reverse of that would be more difficult I would think, getting 3 waypoints, and then projecting lines to get the orthocenter, and then hide the cache at the center. But what if the orthocenter is not a suitable location for the cache? It would be near impossible to manipulate the triangle so that the orthocenter would be the coordinates you want. So I guess the main question here is, can this be done in reverse? Generate 3 waypoints based on one set of coordinates in the middle? I’d like to set this up in my area, but to implement it, doesn’t it have to be worked in reverse? In other words, hide the cache, get the coordinates, and then find a way to make 3 waypoints forming a triangle, with the orthocenter being the coordinates of the cache?

To do so in reverse of that would be more difficult I would think, getting 3 waypoints, and then projecting lines to get the orthocenter, and then hide the cache at the center. But what if the orthocenter is not a suitable location for the cache? It would be near impossible to manipulate the triangle so that the orthocenter would be the coordinates you want.

So I guess the main question here is, can this be done in reverse? Generate 3 waypoints based on one set of coordinates in the middle?

]]> Comment on Mapping and Updating Golf Course Designs in the Field with a Garmin GPS by Peter Mariani http://blog.expertgps.com/blog/2009/04/mapping-and-updating-golf-course-designs-in-the-field-with-a-garmin-gps/comment-page-1/#comment-113 Peter Mariani Wed, 29 Jul 2009 00:19:28 +0000 http://blog.expertgps.com/blog/?p=234#comment-113 I work at a golf course that was GPSed a few years ago as part to a renovation. I have the data in a CAD file. Can you recommend a hand held GPS that would be good for collecting way points for updating changes made made since the GPS work was done. It also would be nice if the same unit could import the cad file. I work at a golf course that was GPSed a few years ago as part to a renovation. I have the data in a CAD file. Can you recommend a hand held GPS that would be good for collecting way points for updating changes made made since the GPS work was done. It also would be nice if the same unit could import the cad file.

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