Question for GPS Owners

Posted by: dougwalkabout

Question for GPS Owners - 01/14/20 06:35 PM

For those of you who use car and handheld GPS units:

For a North American location, does your system ask you to enter longitude as a negative number (-xx.xxx), or as a positive number with the West designation (xx.xxx W)?

I'm writing a guidebook for end users, and trying to explain how different GIS systems designate the coordinates in comparison to car/handheld units.

Thanks!
Posted by: pforeman

Re: Question for GPS Owners - 01/14/20 08:14 PM

I have an old Magellan Meridian Plus and it uses positive numbers. I've got a GPS in our 2008 Prius and it uses positive numbers for input.

I looked at my iPhone (11) and none of the three map apps had an option for longitude/latitude entry. They all expect you to use a 'street' style map or to use landmarks to locate spots I guess.

This is making me think I need to do some serious research on this as it never occurred to me that putting in this information would be problematic.
Posted by: pforeman

Re: Question for GPS Owners - 01/14/20 08:41 PM

Did my 'research' - thank goodness for the internet!

To get the coordinates on smartphone map apps you just have to pick a spot and put a 'pin' on it (usually just touch the map spot for a bit and the pin will come up). The information is then listed in the 'pin' when you touch it and scroll around in the properties/data part of the 'pin' information.

This works for the Apple iPhone map app, the maps.me app and the Google map app too.

This is good to know now and not sometime in the future when I really need it... Thanks for making me think and learn something.
Posted by: KenK

Re: Question for GPS Owners - 01/15/20 12:14 AM

My Garmin's Nuvi automotive gps use N and W. My Garmin GPSMAP 60csx uses N and W. Google maps uses + and -.
Posted by: BruceZed

Re: Question for GPS Owners - 01/19/20 02:35 AM

Lat and Long in North America will always be either have Hemisphere as a Letter, i.e. N/S or North as positive and South as Negative for Latitude and E/W or East as positive and West as Negative. Lat & Long on Wikipedia
Posted by: dougwalkabout

Re: Question for GPS Owners - 01/19/20 03:35 AM

Thanks everyone for your responses -- much appreciated.

I understand how the coordinate system works: I'm just asking for a heads-up on the quirks of the GPS systems you own and use.
Posted by: haertig

Re: Question for GPS Owners - 01/19/20 03:39 PM

Personally, I don't use Lat/Long if there's another choice. UTM is better, but still is not very user friendly IMHO. I have recently discovered something called what3words. Three words are used to uniquely define a location down to (I believe) a 9'x9' square. So you can communicate a very specific location. Put into perspective, if you were describing the location of a parking space, you would be able to specify the front half of the space or the back half. That's pretty good resolution. It's easier to remember and transmit three words than a string of numbers like you have to with Lat/Long or UTM.

e.g., If I wanted to tell someone specifically where to meet me at the Denver Zoo (the front ticket gate in this example), I would say "go to ozone.prop.wasp"

That would be commonly written as ///ozone.prop.wasp or as a link https://what3words.com/ozone.prop.wasp

You can access this via a web browser, or as an app on your smartphone. You can zoom in and switch to satellite view to really see where you are going. It links to Google Maps for directions.

Anyway - I slid a bit off-topic here - it's another alternative to Lat/Long that I think is much more user friendly.
Posted by: chaosmagnet

Re: Question for GPS Owners - 01/19/20 06:31 PM

That is so cool, haertig!

After a *long* time in ham radio Im putting together my first HF rig. Recently I learned about a ham radio specific location coordinate system used for contesting and propagation measurement called Maidenhead Grid Squares (http://www.arrl.org/grid-squares). Ozone Prop Wasp would appear to be DM79ms60. While Maidenhead Grid Squares can be very precise, Im given to understand that they are usually used with eight or fewer characters of precision.
Posted by: haertig

Re: Question for GPS Owners - 01/20/20 02:59 PM

Originally Posted By: chaosmagnet
After a *long* time in ham radio Im putting together my first HF rig.

What a coincidence you mentioned ham radio. I am starting a class to get my Technicians license this evening. Then immediately thereafter I am enrolled in the next class, for my General license. How many years now have I been threatening to do this? I sputter along, reading books (many of which I got from a fellow Colorado ETS member!) but just never closed the deal and went and took the test. I finally figured attending an actual class, with actual real people in it, might get me off my butt. Countdown to that starting is 10 hours from now. I'm excited!
Posted by: unimogbert

Re: Question for GPS Owners - 01/20/20 03:10 PM

Lat/Lon seems to be the standard while UTM is better for estimating distances between points.

Go git'em Haertig :-)
Posted by: chaosmagnet

Re: Question for GPS Owners - 01/23/20 02:52 AM

Welcome to the hobby haertig!

Im a competent operator with around thirty years of experience on VHF and UHF voice, Im planning to do more listening than transmitting for a while on my HF rig.