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Author Topic: let's talk gps stuff...  (Read 6893 times)

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Offline kylepeterson

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let's talk gps stuff...
« on: November 30, 2017, 07:59:58 AM »
so, you want a shiny new GPS to .... do something for your motorcycling/outdoors adventures ?

OK, here are some things to understand:
tracks - are generally like gold nuggets of wisdom. someone actually recorded hundreds or thousands of track points as they canoed (yes  boats too!) hiked, biked, motorcycled, glided (gloed? lol) or otherwise traversed the planet. sometimes they include waypoints, which are like diamonds in a gold mine, for free. tracks CAN be generated by a computer /Program also, but generally they are recorded wonderful things you can trust to be good /reliable in every way.

waypoints- these are diamonds. someone recorded a locations' coordinates, along with (if you're really lucky) a description, photos (geotagged) , videos, audio (from the river babbling along) , or even typed out some history of the location, hours  of operation, gas stations near by,  river levels (for crossing/fishing) or maybe even a URL link to the local happens/Facebook pages in the area. again, waypoints are diamonds !

routes - are the devil. they lie. they deceive. the flirt. they cajole. they sell you a beautiful dream, but deliver a sandy crack. these are computer generated GUESSES that some evil scientist created an algorithm years ago, to produce more lies spun off from previous lies. routes are generally a way that MIGHT work, but haven't been tried/tested yet. the road might be there, or once was, but more than likely you will have a u turn out twenty to complete before your destination.

maps-  are not tracks, or routes ! maps are simply the background that entertains your mind and orients your soul as you look at squiggly lines on the screen. maps can be topographic, photographic, simple, or very complex. you might can build a route you want to follow via that map, if it has enough roads and trails on it. more than likely you'll want.....

routing data- routing data is what most people confuse with maps, tracks and routes. it's none of those, but plays a role in all of them. routing data are the trails, roads, passes, etc that mapping programs use to draw those imaginary routes (and sometimes tracks) on the screen. routing data -can- be included in, or tied to, a map, but lots and lots of maps do not have routing data included. this frees up a lot of space for smaller file sizes, or higher detail in images...

which leads us to vector vs raster...

vector maps-  are tiny in size but broad in coverage and detail. these are maps that the GPS creates from math, on the fly. it's data that tells the programs where a steam/clubhouse/road is, but doesn't depend on images being stored to produce what you see. it builds the images, as you all for them in your panning and zooming around the screen. for instance, the entire USA is about 4gb in size, which is tiny for the amount of detail it has.

raster maps- are images. compressed or not, they depend on the level of detail in each image as to whether it will give you a good zoomable map, or just a basic over view of the land. the entire USA of a similar detailed view to the vector map  in raster (image based) format would be around 100-300gb, or more.

poi- points of interest, were nuggets of gold once.... back when their information was relative, to whatever company thought they were important. or were paid to say they were important. or some group of folks thought they needed to be distributed across the globe. these are similar to waypoints, except they are usually ten times removed from your current hobby/activity, created by someone who might have ridden a motorcycle once, at aunt Emma's birthday party.... but they didn't include food info like waypoints usually do. pois can be great, but they usually are dated.

.....
just give 'er the berries !

Offline kylepeterson

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Re: let's talk gps stuff...
« Reply #1 on: November 30, 2017, 08:33:50 AM »
map overlays.....


the base map is what your eyes like to see, behind the tracks/waypoints/overlays/weather radar/traffic layers, that are on top of it.

the base map can be raster (image) or  vector (computed on the fly). your additional layers can also be vector (computed) raster (image) based also.

map overlays are very useful for displaying local maps from trail head information stands at parks, online sources like forums, aviation charts, marine charts, or anything you want to have ovelayed on your map.

the first image is an example of osm (open street map) showing land based roads only.

the second shows a local chart at the bar that I snapped a picture of and created an overlay, so I could see where the lighthouse wreckage should be.

the third shows just how large an image can be overplayed onto a map, this covered several miles.

it takes about five minutes to snap that picture, Geo reference it, and overlay it on whichever base map you're accustomed to using...
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Offline Fencejumper09

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Re: let's talk gps stuff...
« Reply #2 on: November 30, 2017, 08:46:50 AM »
Now that is something new to me! What a cool idea! Thanks for sharing Kyle!
2013 KTM 690 Enduro/Sumo
2011 KTM 990 SMR (Oh Yeah)
2002 YZ250 (EG295)
1985 Goldwing (ish)
Remember, a boss doesn't always do smart things, but he always does them like a boss. - Paebr332

Offline kylepeterson

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Re: let's talk gps stuff...
« Reply #3 on: November 30, 2017, 10:30:32 AM »
creating a park map overlay....

lots and lots of parks and trail heads have maps on display. unfortunately their websites are usually decades behind the times, and have little to no mapping functionality. thanks to modern tools, you can create a map overlay, that is Geo referenced, and actually follows your base map as you pan and zoom. this is extremely helpful for hiking parks, and events that are large.

so, you take a picture or download the map from their website....

then add reference points that match both the landm marks on the downloaded image and your own base map.

finally, a kmz (Google earth uses kmz as their file format for overlays) is created, which is overlayed.

this layer can be exported and shared with other folks, very easily.

here is an example of the process....
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Offline kylepeterson

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Re: let's talk gps stuff...
« Reply #4 on: November 30, 2017, 10:41:55 AM »
OK, everyone doesn't hike. I know this. just about everyone here has been to our plans to go to Barber vintage fest at some point. here's another example of what a map looks like overlaid for an event. it's a lot easier to find bathrooms, first aid, food, and basically anything you need in the event area.

just give 'er the berries !

Offline kylepeterson

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Re: let's talk gps stuff...
« Reply #5 on: November 30, 2017, 10:46:55 AM »
in the previous post I attached the event map that was in the screen shots.

you can download that to your phone or computer.

Google earth, Garmin basecamp, gps visualizer (this one is online only), and if course several android/iOS applications /handheld GPS can display this kmz file , as you walk/drive around.

I won't get into the file location here, as there are so many applications and gps manufactures that it changes too much to cover them all.

just give 'er the berries !

Offline kylepeterson

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Re: let's talk gps stuff...
« Reply #6 on: November 30, 2017, 10:53:50 AM »
file types.... everyone dreads this part because they have to convert stuff, before using it.

normally the most widely accepted file type for tracks (and routes) or waypoints is GPX.  yup I spelled it right, that's an X n the end. lots of gps manufacturers have tried to push their proprietary formats (to prop up their own business and stifle competition) but thankfully most of them have died because open file standards rule the electronic world.

so..... gpx is your friend. you can download, import, export, edit, upload, and share with just about every modern mapping device, if you're using GPX.

yes, even Google maps, Google earth, android applications, iOS applications, stand alone hiking/biking GPS units can handle this file type.

attached is a screen shot of some of the other popular file types, and the applications that normally use them. eventually they will fold, and succumb to the gpx standard, give them time. ;-)

just give 'er the berries !

Offline Fencejumper09

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Re: let's talk gps stuff...
« Reply #7 on: November 30, 2017, 10:57:58 AM »
Are you going to go through the process of making reference points? Are they latitude and longitude points?
2013 KTM 690 Enduro/Sumo
2011 KTM 990 SMR (Oh Yeah)
2002 YZ250 (EG295)
1985 Goldwing (ish)
Remember, a boss doesn't always do smart things, but he always does them like a boss. - Paebr332

Offline kylepeterson

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Re: let's talk gps stuff...
« Reply #8 on: November 30, 2017, 11:04:28 AM »
"that's all fine and good Kyle, but I really just want the file I can download and USE in my bike. how about just shutting up and giving me a ride loop, already ? "


I totally dig this. nobody wants to read a book to decipher a recipe  , they just want the dang recipe !

here, attached is a very simple gpx file for you to download and try out. either in Google earth, sine stinking phone app, your stand alone GPS, or just commit it to memory and go for a ride. totally up to you.

attached file is a fun street ride.

just give 'er the berries !

Offline kylepeterson

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Re: let's talk gps stuff...
« Reply #9 on: November 30, 2017, 11:28:31 AM »
Are you going to go through the process of making reference points? Are they latitude and longitude points?

sure can.

there are lots of ways to do this.

google earth can take an image (I believe jpeg /png are the only accepted image types) and allow you to stretch/skew it to fit the background behind it. I'm not a fan of this method because it takes so much time to stretch and skew the image, and each time you do so it effects the rest of the image, making your previous skews off, just a little bit.

basecamp can do this also, but for sanity, I'll just say it "can" , and leave it at that.

probably the easiest and fastest way, is with an application. yup, simple applications are jumping ahead of the game with each update.

basically, you pick a landmark on your image , like the point of a lake, end of a road, edge of a building, or similarly easy-to-identify landmark, and push a pin in it . then you swap to the basemap layer and select the same location on it. this creates a reference point. after creating 4 (or more) reference points, the image will be Geo referenced by the application.

... but what does Geo referenced mean, anyway?

Geo referenced images are basically just images that have a grid of points stretched across them. each of those points correspond to your maps points, so the two grids line up (behind the scenes, invisibly) and the image appears to float on top of your preferred base map. since the image is covered to a kmz file, all those points and the image itself can be shared in one file. it's very handy, very fast, and the number of applications that can display is many.

I'll do a screen capture of the process in a free minutes and upload it to YouTube.
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Offline kylepeterson

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Re: let's talk gps stuff...
« Reply #10 on: November 30, 2017, 12:02:42 PM »
here's a quick n dirty screen cappture of the process.

sorry, no audio, you probably don't want to hear the Yankees arguing about which pizza to order for lunch ... that are next door in the hospital waiting room. :-(


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Offline Nice Goat

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Re: let's talk gps stuff...
« Reply #11 on: November 30, 2017, 12:08:53 PM »
If we had a "Most Amazing New Thread" award, this thread would win.   :-*

Goes directly to sticky status....


« Last Edit: November 30, 2017, 12:09:48 PM by Nice Goat »
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Offline kylepeterson

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Re: let's talk gps stuff...
« Reply #12 on: November 30, 2017, 12:31:12 PM »
more GPS stuff....

it doesn't matter what your preferred device is in this day n age, wrist watch, smartphone, stand alone, paper map, or all of them at once, it's just coordinates on a screen.... OK paper in some cases.

for instance, N 32.37113° , W 088.69923° will show you were I'm sitting right now. give or take 100 meters, since I'm sitting on the first floor of a four or five story building, there is a lot of "bounce" of the satellite pings, in between floors.

which leads us to ....
"how does that stuff work, and where does it work?"


it's really really simple:

the satellites (personally I think it's really just ground based, the world is flat, and the moon is a floating boobies) send a time stamped "ping" of data. if you have 3 or more pings to compare, your GPS antenna wool receive those pings and compare how long it took to get from each originating satellite, to your phone.

ahem, oops, I meant "gps unit". not phone. phones can't do GPS stuff in the middle of the dress.... hold on we'll get to that in a second.

so easy of those pings has a little bit of info, including the satellites position in the sky, and the time  , when it was sent.

your GPS unit compares the time lapse between the ping being sent vs your GPS device receiving it, and then does some simple triangle math to decide where you probably are. each time you get another ping, you get a better guesstimate of your location. add more satellite pings and you get more accurate guesses.

" why are you calling it guesses, idiot? "

I'm calling it guesses because there are lots of things that effect the radio wave pings, to speed then up, slow them down, reflect, refract, and bounce them around.

think about a spotlight shining down on the length of a shiny sky scraper. the windows will reflect some of the light, some if it will be direct also. your GPS has to choose which one of those reflections is the "real" signal, unaltered by the reflections. each "bounce" of the signal lies to the GPS, because the elapsed time is not exact anymore. keep in mind we're not talking seconds, but splits off fractions of seconds. each one matters and throws off the math in the process.

a big lake can give you extra "bounces" on the original signal.

sky scrapers too.

large canyon walls , yup.

if you happen to be under a few stories of a building, yup, lots of bounce if you have a usable signal at all.

.... lunch time .....


just give 'er the berries !

Offline kylepeterson

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Re: let's talk gps stuff...
« Reply #13 on: November 30, 2017, 12:32:33 PM »
If we had a "Most Amazing New Thread" award, this thread would win.   :-*

Goes directly to sticky status....


there will be a reference to sections when I'm done.....


and then prime can skip all the crap and go to the gpx files to download ;-)
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Offline Fencejumper09

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Re: let's talk gps stuff...
« Reply #14 on: November 30, 2017, 12:55:26 PM »
Awesome! I never realized the capabilities of Locus! I just used it to record super fun singletrack!
2013 KTM 690 Enduro/Sumo
2011 KTM 990 SMR (Oh Yeah)
2002 YZ250 (EG295)
1985 Goldwing (ish)
Remember, a boss doesn't always do smart things, but he always does them like a boss. - Paebr332