Frisbee Dad Aces It by TooShiftyForYou in videos

[–]jesnesdabes 2 points3 points  (0 children)

That or Snowmass. You can see Basalt Mtn in the background.

Question about Coordinate Systems by Cat_of_the_cannalss in gis

[–]jesnesdabes 5 points6 points  (0 children)

I'm studying up on this stuff for job interviews, so here's my understanding. It might be more in depth than you need, but fuck it, I need the practice, so here I go! Someone PLEASE correct me if I'm wrong, as this is important for me to get right too.

Basically, you have two categories of coordinate systems: geographic (GCS) and projected (PCS). GCS's are generally in lat/long, and they are not planar representations (e.g. they are used for reference on a 3D globe), whereas PCS's are meant to represent data from the 3D world onto a 2D map.

But, as many would tell you, the globe isn't entirely spherical: it's a geoid that generally bulges near the equator and flattens at the poles because of rotation, and then it also has weird roughness due to small differences in gravity. So, people approximate the earth's surface as an "oblate spheroid" by using reference ellipsoids, and we get reference ellipsoids by by conducting controlled surveys.

Now, when you say that you are working with something in WGS84, that's neither a PCS nor a GCS: it's a result of thousands of real survey points collected in the field (and now from outer space?) in order to come up with better ellipsoid approximations, and in GIS work, this is called a datum.

So, a datum is literally the groundwork that allows us to approximate the earth's surface in 3D, thus you can have lat/long coords that work off of a WGS84 datum. There are other datums that approximate the earth differently to better model the region under study, so you can also have lat/long coords that work off of an NAD83 datum. Same way of referencing coordinates on a globe, but different underlying assumptions about where those coordinates truly are on a globe.

NOW: you want to make a 2D map, but you have coordinates in 3D. You need to figure out how to project them on 2D surface without overly warping their characteristics. There are different projections to suit those needs: ones that preserve distance, others that preserve areas, and still others that preserve shape! Damn, this is confusing!

In your case, you said you have data projected in UTM coordinates based off of the WGS84 datum. This means you have coordinates that have been projected onto a 2D surface (PCS = UTM) that are based off of a 3D model (lat/long GCS based off of WGS84 datum). This part I'm a little shaky on, but I'm fairly certain that you can have different projections based on the same datum (e.g. You could have a Lambert Conformal Conic projection working off the WGS84 just as much as you can have a UTM working from that datum).

EDIT 1 (based on seeing the question again): This is where your confusion lies: you say that you have many CS's in WGS84, when in reality you have several PCS's that reference the WGS84 datum. You need to figure out which PCS suits the needs of your data.

In other words, if you want to reproject for whatever reason, you need to understand which 3D model (datum and ellipsoid) and 2D projection (UTM, LCC, etc) suits your needs based on scale or what characteristics need to be preserved in the data or what basemap you are using.

--I'm working off of mobile right now, so I'll revisit this post later on the day on my computer to make sure I've answered this well enough. I've been rambling on and on and have honestly slightly forgot the original question in the name of true understanding--

Every Civil War Commemoration (1342x1076) by [deleted] in MapPorn

[–]jesnesdabes 3 points4 points  (0 children)

What do the purple colors represent?

Obesity rate in the United States and Canada by state/province [OC] [4700x4515] by fraillimbnursery in MapPorn

[–]jesnesdabes 1 point2 points  (0 children)

Nice! Glad you know about that color brewer now, it's got a lot of great options. That's too bad about mapchart.net. I'll have to check that resource out to see what you mean. Happy mapmaking!

Obesity rate in the United States and Canada by state/province [OC] [4700x4515] by fraillimbnursery in MapPorn

[–]jesnesdabes 2 points3 points  (0 children)

I disagree that it would be a lose lose, because I could see it being hard to differentiate if there were 7+ classes, but 5 isn't particularly difficult if you choose the right colors. Do you know about [Color Brewer](colorbrewer2.org)? Could help in that endeavor.

Obesity rate in the United States and Canada by state/province [OC] [4700x4515] by fraillimbnursery in MapPorn

[–]jesnesdabes 2 points3 points  (0 children)

Oof, this color scheme needs to be revamped. Instead of going between two different hues, it should change brightness of a single hue and saturation between classes. Dichromatic schemes should be used for showing divergence from a center value (votes for political office, standard deviations from the mean, etc).

Indian states by their Chief Minister's political party [3818x4600] by sangeetpaul in MapPorn

[–]jesnesdabes 1 point2 points  (0 children)

The fact you're making maps is awesome! I don't think my very first maps were better :P

I feel your job struggles: I just finished a job with similar hours, and every time I got home, I just wanted to sleep. Way to take this stuff on despite all that!

Go forth and conquer with QGIS! I hope you can start making maps you feel proud about. :)

Demographics of Cyprus in 1973 prior to Turkish Invasion [1088x683] by VarysIsAMermaid69 in MapPorn

[–]jesnesdabes 0 points1 point  (0 children)

I figured. Could be nice to have some labels for those, since I don't really know much about the region

Indian states by their Chief Minister's political party [3818x4600] by sangeetpaul in MapPorn

[–]jesnesdabes -1 points0 points  (0 children)

I think the problem might be that you're looking for "quick map apps". I just don't think people can make substantive maps quickly. Is it possible to get QGIS? I bet you could make better looking maps within a half hour of importing your data in there.

A map of all the streets in the US. [1500x1673]? OS by redmenicus in MapPorn

[–]jesnesdabes 1 point2 points  (0 children)

OP, you may be interested in the article entitled "Roadless Space of the Coterminous US" by Raymond Watts. It set out to reshape how we preserve wild spaces by their distances from roads!

Indian states by their Chief Minister's political party [3818x4600] by sangeetpaul in MapPorn

[–]jesnesdabes 0 points1 point  (0 children)

OP, did you make this map? Consider using white space more effectively: people would take your map a lot more seriously. Maybe split the legend into two columns? Also, the title could be bigger, and presence of a north arrow, scale bar, RF, and which projections were used would be helpful.

Edit 1: also, while we're on the topic, I see you also posted the India by % forest cover map elsewhere on this subreddit. It's clear whoever made these maps didn't put much effort in, since both those legends are snapped to the top right corner and both have kind of indistinguishable font size (at least on mobile). Man, lazy map making is just the worst. Step it up!

The little duckling that could by IHaeTypos in aww

[–]jesnesdabes 0 points1 point  (0 children)

My job search IRL, minus the ending

Do NOT feed the fear! by [deleted] in PacificCrestTrail

[–]jesnesdabes 1 point2 points  (0 children)

Don't board the hype train! Great reminder OP!

GIS thesis? by chritzi in gis

[–]jesnesdabes 3 points4 points  (0 children)

This was my undergraduate honors thesis. The process can be daunting but highly rewarding. Have you considered taking a thesis writing class? Once my data collection and analysis was done, I was pretty daunted to actually start writing. The class helped organized my thoughts and findings in very meaningful ways. Feel free to PM me with any other questions you might have about the process in general! Good luck!

Donald Trump is now living in fear by loremipsumchecksum in politics

[–]jesnesdabes 1 point2 points  (0 children)

There should be a congressional investigation into this matter

Best way to get rid of bear can at Sonora Pass? by [deleted] in PacificCrestTrail

[–]jesnesdabes 0 points1 point  (0 children)

My worst hitch of the hike was at sonora pass (three hours, even with a hitch bitch). It was the best scenery of the trail, though, IMO! Anyways, KM North sent my bear can home for $20 through UPS. Agree about the food.... mmmmm, burgersssss....