good morning everybody my name is Malia Kennedy or in introducing coordinate systems and map projections with me is I'm boyish outage excuse me we are both members of what's called the projection Engine team at ESRI we deal with coordinate systems map projections transformations so first off we're gonna set up a problem that a lot of people encounter when they're working with this this area of the software where is my data so here in art Pro I have an orthophoto image of Palm Springs area and I would like to map the Palm Springs town border so to my map I add a polygon layer that kind of marks basically it's a polygon layer of Palm Springs and when I turned the polygon layer on nothing shows up so but when i zoom to the layer for example I see that the layer actually actually draws on the map but probably it's on the wrong location so if i zoom out on this map to the whole world view I can see that this is the error location of my orthophoto image and here is the location of my polygon so pretty much it is clear that data doesn't line up and the reason that some what is wrong is probably wrong something about coordinate system and or missing transformation so in order to understand that so to know and figure it out what exactly is happening let's go back to Malita and she will explain all the details before we fix the problem so we're going to have three main sections to this talk we'll talk in general about coordinate systems we'll talk more specifically about map projections the algorithms used within the coordinate systems and finally we'll end up with talking more about transformations so we have a couple we have two different types of supported horizontal coordinate systems Geographic and projected and what does a coordinate system tell us well it tells us distance between points it tells us location and finally it can tell us direction so for instance how far is it from San Francisco to Los Angeles and we've got four different answers up here none of them are equivalent and why are there so many different answers to this and of course it depends on what coordinate system we use to measure that distance so what what are the coordinates for downtown Los Angeles and again we've got another four different answers these are in various different coordinate systems well which one is correct well they all are depending on what coordinate system you're using finally you know maybe you want to know what direction the North Pole is because you want to find an azimuth between two points well it depends on your coordinate system it could be down it could be to the right could be to the left it could be not on the map at all so as I said we have geographic coordinate systems and projected coordinate systems very quickly geographic coordinate system you're on a 3d model of the earth three spherical surface and in this case we've got a point P on the upper right and it's got the coordinates of longitude 80 degrees east and 50 degrees north those are angular units if you've got a 2d display we throw that Geographic quarter system data up on there we basically are projecting it into a flat plane it's called a pseudo plat car a projection again there's point P again up there in in Russia and again we're still at 80 degrees east 80 degrees north but right now we're treating these angular units as if they're dis linear and just displaying them projective coordinate system it's instead you're using linear units you're going to be using probably x and y or eastings and now it's look at the parts of a coordinate system as is defined at ESRI so geographic coordinate system again Earth model is a sphere or spheroid ellipsoid and working from left to right we've got a prime meridian an anger unit a datum and the datum is based on a spirit or an ellipsoid so let's say we now we have a projected coordinate system we're gonna inherit that an entire geographic coordinate system and then again we're gonna have a projection which is basically just the name linking to an algorithm any parameters needed by that projection and then finding a linear unit so there's two ways you can specify a coordinate system what's called a well known ID or people call a wicked and then or by one on text which is a string ASCII string that gives you information about the coordinate system we'll look at both of those so when you're in Maine software desktop or pro you can actually search by the wicked or look what buy things by name and so when you look at the the core system property page down the bottom you can see in the current coordinate system we've got highlighted there there's where the W key ID is so in this case it's W just 1984 four three two six and it has an authority from a group called the epsg psg the name is European Petroleum survey group it is actually under the the aegis of the i/o GP it originally started out as an oil and gas industry standard because people weren't using the same information they were using very variations of the same information and so basically now they have the status set that they publish online and you can download it as a access database as well I'm a member of the committee that helps maintain that and it's gone way beyond the oil and gas industry now so basically any coordinate system or transformation someone is using and you can prove that someone's being using it you can go into this registry and then everyone if they use that that it's much more easier to interupt between different companies to between different definitions on the one on IDs if you see a number that's below three to seven six seven it's defined by epsg that's the range of codes you see numbers above that generally of course in our software it's going to be defined by ESRI but there are other authorities as well we may change an ID over time for instance if we put in a definition we'll give it an ESRI ID in this case originally the current definition for web Mercator we hit we put a definition in basing on what we knew about how it was being used and in Google and Bing for instance and Yahoo and then later epsg added it so they of course that'll it with their own number so we did what we call a code change so right now either of those IDs 102 100 or 3 8 5 7 will work in the software and you'll see us occasionally slip back and forth between to two numbers one reason when we do that if you're working in a server client environment a server may be older and it's possible it only knows 102 100 so for instance the client may say ok I'm gonna go ahead and I'll ping a server with 3 3 @ 5 7 if it doesn't know it you'll switch over to the old ID and try that again to try and make sure that it gets the answer so here's the well-known text this is for a geographic coordinate system and you can see we've got there listed the geographic coordinate system the datum the spheroid primering and the angular unit so it tries to be as complete as possible so you don't need to go look anything it up if we now on add on the projected court system information again we've got that whole geographic coordinate system now we have projection the parameters and finally the linear unit the only thing you're gonna have to look up is the projection name itself so a system would have to implement that projection in order to be able to support this coordinate system so one of the tools that we have available is the defined projection tool that updates the information on a data set that's all it does it updates the metadata so one thing we see people do a lot is they say ok all my all my data that I'm working in it's all in web Mercator I've got this new data coming in I'm just gonna define its web Mercator and then suddenly doesn't line up because basically they've overwritten the metadata and that data was not in web Mercator it was actually in latitude and longitude for instance or it was in the state plains in our UTM zone so only used to find projection till if the data has no coordinate system which I'm sure most people have seen show up or possibly someone else is to find it incorrectly and you need to fix it can you I'm going to talk briefly about vertical coordinate systems so vertical coordinate system how high is not Everest and again we've got four different answers for that including two that are pretty close just over 29,000 feet they're not exact and again that's strictly on what vertical coordinate system is being used so the VFC spherical coordinate system just defines where the origin is for your height or depth values in this picture you can see that in in the ocean area those depths which are positive down are relative to what's called mean low water and that's just a case where you you want a really low surface so that ships don't go aground no matter how high the or how the depth changes over time I'm sure you generally have something closer to mean sea level and again in this case now our Heights are positive up so we have two different types of vertical coordinate systems one is a geometric model in this case we've got their surface all lumpy and bumpy and then you've got an ellipsoid that dashed blue line is an ellipsoid surface and that's weak that's our geometric model of the earth and you can see it fits pretty well everywhere the other type that you'll see people use is some sort of gravity related system those are tidal levels those are basically the vertical coordinate systems for our country they have some tie to gravity and you can see that the solid Green Line is also lumpy and bumpy not as lumpy as bumpy as their surface but again not as smooth as the geometric model so gravity related earth model generally is related to something called the geoid which is this really kind of lumpy bumpy surface it's a geopotential surface which basically means gravity is about the same everywhere on that surface so it's called a level surface it's complex shape which you've got underneath the ground can affect it can pull it down and away people model it is they generally have a file of offsets between it and the geometric model so you'll see a joy detroyed model Waffen of a file and the values in that file or the difference between the joy height service and the ellipsoid surface so here is a model of egm 2008 that's the current world wide joyed model and it's been exaggerated 12,000 times so it really is if you really look at it it's it's smoother than an orange surface but we've wound it up so you can really see where the the geoid is going higher and lower than the geometric surface so there's goes South America around the corner so a vertical coordinate system has these pieces and again working left to right there'll be a datum or a vertical datum a vertical shift a direction and a linear unit so that whether it's a datum a vertical datum tells us immediately whether that vertical coordinate system is using the geometric model oops little heights or some sort of gravity related surface and in the literature generally you see if it's an opioid of height you'll see a lower H used for it and then for some for a joy service a joy height you'll see a capital H used but we don't need to set roaming the software we have two parameters that are built in the bcs definition one is Direction it tell us whether the divide the Z values are positive up or positive down that's the direction and then there's a vertical shift where you could put in an offset to an existing VCs for instance you might be working locally and you're working on any VD a t8 which is a u.s. vertical coordinate system but for your particular area everything's a metre and a half off so you could code that into the definition so here's the one on here's an example of one on text ID at one on text and a one on ID for any VD 88 which is again the US current US vertical coordinate system north american vertical datum of 1988 and again you see there there's the two parameters there's the V datum and there's those in your unit and in this case the wicked for that is 5703 so now we'll talk a little bit about map projections that's converting from our bulb soil surface our spherical surface into a 2d representation here's a few of the map projections we support some of the more funky shapes we do like to start on the upper left is brick house star and here's a list of basically the unique algorithms that are in there these are 68 right here there's another 30 that are that are basically variants on these these lists so for instance codeine and wick Mercator has four different ways you can define it in this case you can define it with a point and then an azimuth and then and then where your origin is it can either be at the center at or at what's called a natural origin and ignore or you could define it with two points and again you could have the center of natural origin so this is what I mean by a variance so why are there so many map projections well if you think about it when we try and flatten that opioid 'el surface that surface you can't do it without tearing or ripping or really crushing it to the ground as this graphic shows so you end up distorting shape or distance or area or direction on it so let's look at a definite example so how many people use web Mercator yeah you know pretty much every web services using web Mercator so between Greenland South America and Antarctica this is what it is in web Mercator which one is biggest well in Arctic is one Mercator but you see by if we actually look at the areas of those three the these three areas Antarctica is actually the second-largest South America is the largest in Greenland which looks even bigger than South America is actually by far the smallest of these three areas now we take Greenland and actually map it against Africa which is 14 times bigger if you look at the correct area as you can see it's it's not even close to being right and wimmer hater so which map projection is the best we listed for very common wind here albers equal-area stereographic azimuthal equidistant transfer Kader and of course it depends on what you're doing so albers equal-area conic preserves areas or preserves relative areas I should say so for instance if we look here and we look at Greenland you can see that it looks pretty small it does not look like it's this large as Africa and if you look over on the east sorry on the west side or the left side for for Australia you can see it looks like it's the shapes a bit distorted but that area is being preserved now for some reason maybe you want to preserve angles and so this is a stereographic map so basically if you're going from the centre and you you measure from north over to your angle you're gonna get a correct azimuth here's another one as we go equidistant this maintains directions and distances but only from the centre so pretty much there's no map projection that I'll maintain all distances if you have to do other things to help minimise that distortion in that so for instance if we're going to measure a distance you know from say London over to Tokyo because it's not going through the center of the map it's not going to have the correct distance so if you're working more large-scale for instance in a topographic map some sort of cylindrical projections often pretty good like a transverse Mercator or Cassini because they minimize they don't they don't completely correct distances or or areas but they're not too bad if you're working locally so what kind of projections are more or better for larger scale maps one would be an azimuthal if you're working in polar areas a conic for mid latitudes or cylindrical for for an equatorial area and again a transfer so it cylindrical like trans Mercator is good if you have a north-south extent if you're working in like more of a hemisphere for half the world then azimuthal projection not only is about good for polar areas but it could also be good for a hemisphere so some of the ones listed we have stereographic which maintains shapes as Weil equidistant again distance through the center glamor equal area or orthographic which at orthographic is actually like if you had a satellite what it looks like for this kind of light you're working for world maps there's pretty much any what they call a pseudo cylindrical so it's sort of like a cylinder which is rounded edges most of these are equal area so for instance here's two of them the one on the left is he is a new projection from last year Cody fourth on the right is another an older one called Eckert for compromise projections are also used for world data Robinson on the lower left has been used for quite a while including by a National Geographic Society we sing with winkel Tripel also used by National Geographic Society for some of their Maps so the project tool is what actually converts your data between different coordinate systems and so here we have just showing you the tool and then showing you what it looks like an arc PI as well so what happens when we actually project data so in this case we've got an input data that's in a protected coordinate system and we want to put it out to a different projected coordinate system but with the same GCS same datum so we're not going to do a transformation on just a reprojection so if we're starting in the on the left side with a1 and the PC s the first thing we do is we unprojected a lot long values the last longitude values then we project forward into a to the output pcs now let's say we're actually going to change our GCS as well so we need to do a transformation so again the first step is a1 pcs down to the GCS a apply geographic your datum transformation to get GCSB and then finally reproject back to B to our output pcs okay now under our final section of transformations so why do we need to transform our data in this case our base map is an older a GCS called 8050 European date of 1950 and we've got a route and wgs84 and you can see the routes running through buildings is running through yards definitely not lining up with the street network if we now apply a transformation to get from W say T for T d50 now suddenly their routes lining up with their base map so when I rise the term transform or transformation I mean we're changing the data and we're changing the geographic coordinate system excuse me so again we've got our lumpier surface we've got an opioid a model the blue ellipse and axes and we've got our data over the upper-left so that's the Earth's center datum W say T 4 so that datum is centered on the Earth's center of mass [Music] older datums and what I like to call local datums when they redefine people only cared about the local area they weren't trying to match the entire world so 8050 or European European datum 1950 you can see works really well on the upper left portion of the map at the diagram looks terrible everywhere else so older datums were just fine for a local area and that's we need to convert them into generally a world based or a more recent coordinate system defined by the country so we've got two different kinds of transformations we support Geographic or datum transformation that converts between the two geographic coordinate systems and we've also added support for vertical transformations so Geographic or dam transformation so here's an example of the one going from IDI 1950 to WC nineteen eighty four eighty nineteen fifty two w eighty-four number one so pretty much when we name a transformation will tell you the source and target so this transformation is defined as going from 80 50 to W 84 so you might ask well how do we get back how do we go from difference 84 back to 80 50 well right now every transformation we support is bi-directional reversible it'll go either direction and we'll handle that for you transformations are always defined for a particular area as well and they'll have their own extent a general extent generally extent and the general accuracy assigned to it as well so right now between w s-- 1984 and edy 50 we have 24 different transformations that convert between the two of them and some of them are here on this diagram you can see they have all kind of different kinds of extents different countries different areas so how do you figure out what transformation to use well we'll try and help you so generally you'll either see and some of the apps will be something like affine transformation or if you're working in desktop or Pro if you use the projector or you're in the map or scene and you go to the transformations dialog there'll be a list and we're sorting that list for you so we look at the data X we look at the gym put it out put coordinate systems you want to use and we try and put the best one at the top of that list so going between two vertical coordinate systems again normally you're going between and sometimes you're going between an opioid Heights to gravity related Heights for instance you might be going from Natick 1983 little total Heights and you want to convert to any bt 88 which is the gravity related system for the u.s. so I've got an example of one of those in between it's the blue and green boxes nad 1983 to ne VD 88 CONUS joy 12 B height and again I'm trying to code in some information there so we have the source and target CONUS is continental US that means the lower 48 states joy 12 B is the model of the joy we're using and then we're gonna will work on Heights its opt-in on the tools so in the project tool you have to click on the vertical checkbox and or it's for us to know you want to convert your Z values as well as your XY values or your legend longitude values so parts of a vertical transformation there's a source of target vertical coordinate system there may be a geographic coordinate system as part of that definition a lot of the vertical transformations may have actually use a file on disk of offsets and we need an interpolation GCS to figure out were they off what the office that's supposed to be so some of the transformations will have this GCS associated with it to also be a method and then any parameters needed by that method so right now the methods we support we support several chiid model formats EG m 2008 EG m84 96 or world ones that were defined by NGA we have four con files for the US and then we have vertical offset and vertical offset and slope methods which are used a lot in europe one thing that we had that started starting with desktop 1041 and pro 1.4 is that's when we started to put in data for the vertical transformations and some of its really big so we just could not put it into the core setups so if you if you or whoever in your organization works with my ESRI to get your your setups if you go to my organization's and then look at downloads and then you can either search on coordinate systems or look under data and content you'll see that there's an arc GS coordinate systems data set up now so basically any new data we get that is needed by transformation is going into these setups they are tied to a release but there usually is only a few things out of every release so like let's see you installed desktop 10 seven you installed pro two point three and then you we want to go to two point four and pro when it comes out if we haven't add anything to that data setup you could leave it right now with this setup it works for a desktop server and pro if you install per machine for everybody so the all the three of those software packages could all use that same setup if you're installing pro per user which I know some organizations do that gets installed to your user location and you have to have a data set up that also installs to use your location so just be aware of that right now it's about 1.6 gigabytes you can't install parts of it you don't install the whole thing there is data for the US from geo con version 1 and entity 2 files from Australia Belgium Canada Spain Switzerland UK for the vertical transformations there are files for vert con on the joy 12v joyed model for the u.s. there's Japanese New Zealand and Switzerland and then for the world there's egm 2008 model so now we'll look at the solution for where is my data so rescue me so we know what the data is we just find out a lot about coordinate system and transformations from Malita so is anybody here interested guessing what is wrong no okay let's take a look what is wrong okay so if I go to we know something is wrong with coordinate systems and let's take a look what coordinate system the orthophoto image is using so I go to the properties and two source go to zoom in and open spatial reference and I can see that orthophoto image is defined in that a three UTM zone 11n it uses transverse Mercator projection has predefined coordinate system using predefined coordinate system therefore has wk ID from epsg here we have the full definition and we see the geographic coordinate system which is north american datum 1983 also predefined so this source basically looks everything fine let's go back and take a look what is happening with the polygon the same thing let's go to special reference Oh undefined coordinate system unknown coordinate system so pretty pretty much it becomes clear what is the issue the issue is that because for our data that we add for polygons we do not know what the coordinate system is therefore the data doesn't show up on the right location so if I go and take a look at the extent of the data I can see that they basically the values are just less than one point unknown unit pretty hard to believe that Palm Springs would span less than a meter or less than feet so and from the numbers we can basically start assuming that the data is actually passed in geographic coordinate system so now this is a little kind of like a trick but because I know the source of my data I know who provided data and I know what kind of data they provide I know that this data is provide probably in wgs84 geographic coordinate system so I can take this assumption because I have a knowledge and I also or if I do not know I contact them and ask them hey your data you gave it to me does not have a coordinate system specified please give me the definition and the answer in silica is jobless just before which usually you're lucky if you get the answer actually so in order to kind of like now fix that Malita told us that when the coordinate system is unknown the tool we should supposed to use is yeah thank you're up yes fine projection tool right so I go and I select the polygon and I specified the coordinate system of course as soon as I select the polygon it shows the coordinate system that the data is already in and it is unknown coordinate system so one way what I can do is I can go and search for the coordinate system here in the window and find it out here by simply searching wgs84 I'll just use WGS and I already basically filtered the whole existing coordinate systems I can just go to world and here's my coordinate system that I can I would like to use ok let me go out so I can change that this is one way how we can also find the coordinate system in impro like if I turn on turn off the filter and I take a look to full folders I have way more options available here so these are all the possibilities for geographic coordinate systems that we have and you can search and you can browse through the files do the people in the back here that okay okay so like yeah as you see like as soon as I select it actually to kind of jump to the favorites folder as well like if your coordinate system is in the favorites already when you select it is going to not go through the whole file system and kind of located there if it is in the favorites is going to pick it up in the favorites right away so it's going to be there for for sure so those who you were probably in deep dive tour submission demo theater probably you know that I use a lot of Slovenian coordinate systems in that case that's why I like my favorites here has playing accordion so I actually I'm using your example it's actually here so I follow that another way that like you can also do that in our case is not going to work but I just want to show you that it is possible and you can do it is you can also use the spatial filter so like for example if you have your data that is specified in particular coordinate system or like particular coordinates you can take those coordinates and you can use the spatial filter to find out what coordinate systems covers that so order to do that you go here on quite right side and you can basically set the spatial filter and then you can basically basically set it up in different ways you can set it up by the date that you have usually it's like you already can special specified it by visual visual current visual extent that you have on your map so there are different ways or you can just manually put it in whatever coordinates you would like to what what you're using and then it's going to automatically do that for you so in my case I'm going to just use the current extent which is automatically selected here I have with me zooming here I have the values that are kind of like approximately to the extent but what I can also do is like I can change the units so for example I can say like okay I want to see that in the degrees and here are the decrease values and if you can see like these degrees are pretty much very similar to what we were seeing in the data extent okay so let me apply this filter I just want to show you how this works as soon as I apply the filter most of the coordinate systems but basically disappeared I don't see anymore Australia I don't see anymore Africa Asia I'm not sure why the Europe is here but probably there's a reason for it so yeah this way like you can basically filter different coordinate systems based on the coordinates you have and maybe you can start guessing or help you to figure it out what is happening so now like just for fun we can take a look what we have in North North America of course Canada we're not going to look but like for geographic coordinate systems these are the coordinates we have coordinate systems we have and one of them that shows up is also like specific California coordinate system similarly from geographic coordinate systems you can also have projected coordinate systems I think right now how much I see here there is no let's take a look continental like yeah Continental doesn't have Europe doesn't have Africa doesn't have anything so it's already sorted so if I'm kind of like it shows North America of course because we are in North America another interesting thing is like it really in UTM and just let's say we are double just before the folder has northern hemisphere does not have South hemisphere because South hemisphere is not part of our extent but if you look up on if you open the northern hemisphere there's only one zone that shows up and this is the zone 11 n which our data is actually in so this way you can filter your coordinate systems based on the extents in order to do that you cannot like once you're found whatever you're looking for you can also like clear the spatial filter as well so that you can get back to what you previously have so now I'm going to clear it and as soon as I do that I see way more options out there available again one thing that is also very useful and military showing different projections most people think that the projected coordinate systems that we have here that's the only thing what we support but it's not quite true you can select and this design any projected coordinate system you would like to have and the same is valid for geographic coordinate systems and vertical coordinate systems so if you have something custom that the customer is using it is not defined by Hazari it's not defined by epsg you can still use it in the pro no problem no issues at all by clicking here the new new coordinate system as a new coordinate system you have options new geographic coordinate system you projected coordinate system and/or 30 new vertical coordinate system you zoom in you can also like import the coordinate system from some prj file that you have in certain data and you can add it to to it so I'm just for funsies I'm going to add trying to just to show you a coordinate system projected coordinate system how you basically specify it yes you set it up the name like my CS you can set it up the different units these are the units that we are supporting there a lot of units so you're not just link to the limit you're not just limited to defeat you can use others as well and of course yes there are different projections as Melissa mentioned there are six to eight projections all of them are listed here as well as all the thirty variants like for example polar serve graphic we have stereographic projection but we also have Polarstern graphic version of it so that's example some projections once we add them we usually don't add the projected coordinate system in sight but you can still use them normally and this is basically quite a list and every single projection has its own parameters for example for that I just select has fallacies thing false noting in option so if I go to for example sorry all right so a rectify skew or morphic Center for example I get the way more parameters right so every projection has its own parameters so you can switch whatever you want and you can use it one that is kind of like a very interesting one since I have time I'm going to talk about it it's a Lambert conformal conic so Lambert conformal conic has like two ways to specify the coordinate system you can do either by using a false easting false northing central meridian and latitude origin but then besides those you can you have two combinations you can specify the coordinate system by two standard parallels or you can specify it by one standard parallel and the scale factor so those are kind of like most commonly ways to define that if you have for example two standard parallels you specify two standard parallels whatever you want and then you keep the scale factor to be 1.0 if you want to use the scale factor and one standard parallel you specify both standard parallels to be the same value and specify the scale factor those two definitions are pretty much basically the same they're just different ways how to specify it instead of adding two different variants into the software we just merge everything together because it's easier and it's pretty much the same mathematical algorithm that goes along with that okay so these are a few ideas that you can find in a pro but I already select the coordinate system I'm going to show you one more trick so I'm going to cancel that selection and return back to the defined project tool if you know your ID of your geographic coordinate system you don't have to go and search you can just type it in so for example W city for ID is 4 3 2 6 as soon as I confirm that the system is going to search for it and add it automatically so like in the tools when you have some particular coordinate system you're always working on you just don't have to talk like search for it and browse it and stuff that I've just type the ID inside and and you it will find the coordinate system so I set it up I'm going to run the tool tool as soon as to finish my data suddenly magically lines up and I resolve the issue one of the things also like if you notice my orthophoto image was defined in that 83 geographic coordinate system using projected one as well and my polygon is defined in that'll just before so I'm basically mixing two geographic coordinate systems in order to make sure everything is correct and it's aligned I also have to have specified I must specify transformation so because we're in the pro pro pro probably in the background already did the work but still let's go and verify that everything is what's supposed to be so I go to the map return back to the properties here I have two options first option is coordinate systems this way is just like what coordinate system of the map I'm using this is the one here and you can see it's constantly defined I could add it to the favorites show up there the reason is custom define is because I'm using a new definition of a transverse mercator when by NGA from 2014 because the other definitions are usually done on regular algorithm and the transformation of course I have to go and take a look yes you cancel ready see the transformation is specified we can just take a look the list shortly there like a lot of options as usual but what I'm doing is I'm picking up the first on the list which I'm kind of assuming it's probably the best one so yeah a transformation is set up so I'm good to go and I can start doing my analysis or just print up the map of the town okay that'll be pretty much it let's switch back to later so some resources for you don't forget that knowledge online knowledge base or technical articles there's a tiny URL here that has a link to some of them don't forget GeoNet I'm not on there as much as I like to but if we get a really tricky question on there for coordinate systems someone will usually at me and I'll pop it in a day or so there's and there's actually some some customers on there who are really knowledgeable as well and generally tend to get questions answered before I can get to them again EPS G not only do they have this online registry where you can look up and search by area to see what coordinate systems or transformations are available there's a guidance note you can get as well if you want to learn more about coordinate systems and transformations the algorithms behind them it's about a hundred and fifty pages I think yeah but that gives you a lot of background on what's being used and speakers bath yeah the secret math and there's we also have a public github repo with some documentation about the coordinate systems things you can download if you wanted to do some sorting yourselves or that you might want to use so that link is there and finally there is two versions and actually I think we've had three editions now for Margaret's book market mayor works and tech supports if you get someone named Margaret and when you call in she is like the tops for coordinate systems and transformations so she is a book on lining up data in ArcGIS particular if you're dealing with CAD data there's a whole chapter and chapters on how to get that data to work with your GIS data please take the survey give us some feedback on this presentation and everyone else is as well we do get the information and I do take a look at it to try and figure out how we want to change these coordinate these presentations over time we want to where we work this for user conference this year so please feel free to give us some tips or if you want to see more in-depth stuff how many people went to the deep dive into transformations anybody yes one they kind of messed up our order because they did the more deep dive on Tuesday Wednesday Wednesday and then this one on Friday which is kind of terrible user conference we managed to get them swapped to the end of the right order anyway please fill out the surveys for our stuff and that's it we have plenty of time for questions if anyone has any questions or even just go bolt for coffee yeah okay [Music] [Music] and I've seen I found like a twenty page which ones are good for right yeah yeah so you know how do you figure out that like the list is giving us money the best transformation what are these transformations where do they come from yeah there's there's PDF there's a PDF file cut geographic underscore transformations that PDF in desktop it's in the documentation folder or even linked to it for the via the help it's online as well yeah there's these humongous tables of stuff so it shows the extents it shows the accuracies I think if you go and you most of those could do come from epsg if you go to that registry it'll tell you the information source it'll tell you it it'll have comments about by the way this was replaced by this one in this year or you know you or or this replaced another one from it from a previous I do have action item on me to do some more documentation particularly for areas where it's very complicated like in the US and Canada and give more details on what these transformations are and what they really mean so hopefully I'll get that done this year and into the doc in the next releases so and the PDF as a also has aerial views so the parameters is also there but like what this is the most like what you can rely on it's like a curious information so smaller accuracy accuracy of your data better transformation is more precise there is like I mean a longitude and latitude and Max mean longitude and latitude values in that table so it kind of gives you the geographic extent of the data it is specified in wgs84 so this is kind of gives you idea you can help yourself with the with the thing that like if your data isn't more it's not so much on the edge of this extent it's more on the middle that would be probably better one to use and of course you follow the area like don't use my no for Gulf of Mexico transformation that is valid in Canada so we'll make sort of hang on sec yeah when we sort that list we take a look at your data extent and we compare it against the transformation extents and the coordinate system extents did you grab it course system extends so you know first thing that's gonna things are gonna sort it higher things that have full coverage for instance so the transformation fully covers your data extent that's going to get higher in the list if we have multiple transformations that have full coverage or even the same partial coverage percentage then we'll start tiebreaking by looking at the data accuracy and the transformation accuracy and we'll start sorting by that at that point it's easy to fool you can fool it by putting having extra data in occasionally even a base map will throw it off and think you want the world or not what your little data is so you just have to kind of watch out for that if you're doing a lot of that kind of work so is this on this or something else okay [Music] [Music] yeah don't agree okay did you still have a first [Music] [Music] yeah so so this is the particular this production the data is actually in in a database so it's an Oracle and it's sto GG o med geometry format and so so right now he's working on the Oracle side to fix the coordinate system rather than on the ESRI side my personal opinion is whatever works so if it's working then that's perfectly good I mean I mean this one thing you can do is is do that and then check it in ArcGIS for instance you can you the measure tool will allow you to calculate geodesic lengths so you could use that to do a quick quick check on it okay I fixed it you know make sure our chest is looking at the most recent version of it and then check the geodesic link does it agree with what I'm seeing in in Oracle and and the same thing there is you can double-check and say okay this is things show up in the right location with random base map that I get from ESRI then again that's another double check against that yes this was the right thing to do but but yeah particularly when you're working with and that's one issue with the one on texts and the way we define the coordinate system is that everybody has like their own little way to do it so when you're working like an Oracle or you're working in Intergraph or whoever you've got there's there's reasons why you might want to use them on the first edge to get third definition correct and then see how is Ria's going to respond to it so particularly with working with Oracle I think I would agree with you I would try to fix it in Oracle first and then double check and just make sure okay we're good to go it's working fine in rjs yeah yeah and then the second thing is when we have a leader that right so so pretty much in in both desktop and pro once you set up the map or scenes coordinate system and and like Pro definitely has a default right that desktop doesn't but when you add that data in and you keep adding in more layers if they're in a different coordinate system we're gonna reproject it to match whatever the map or scene is in one thing that could happen is that there might need to be a transformation but we sometimes we won't apply it automatically so that's one thing to check particularly desktop does not set a transformation automatically and you get that warning message right there's a you know difference Pro has the same warning message but it's turned off by default so like if you really rely on that or you think you think people you work with should be worried relying on that you could turn on for them there's a way and the options to deal or know where you just actually were I know where it is I don't know where it is I've seen it in the in the options for Pro but there's a way to turn on so but in Pro like as you saw when he did his demo when he went to check the transformation it was already set so Pro in general tends to go ahead and set the transformation for you because it doesn't have that warning message and they usually also pick up the transformation it comes first on the list yeah so like if you have like Melissa mentioned before that you can mess up your transformation with base map right so like for example in my case when I'm working on Palm Springs area there's going to be different transformation available than when I have a full map right so if I if I have all the data in the Palm Springs and then I later on I decide to add the base map which is in a web Mercator for whole world is going to take oh the extent of the world is the base like this the full world so the pro is going to behind the scene might switch to the transformation that covers the most possible data it's not not necessarily even though you're using it for just a small area of the Palm Springs right it's going to actually use the worst not so the best Meishan for your area but he's going to try to kind of compensate for the whole for the whole dataset so oh yeah yeah yeah yeah you can always go write it in it yeah yeah and actually I've I've had an I've had a bug and action item to try and change that possibly like to ignore the basemap when you're working with your data because normally that has a much bigger extent than the area you're interested in and and the guy who's kind of in charge of the the map side of both desktop and pro we're like yeah we should really look at that so like my action item when I get back to the office it's a goof make sure there's bugs in the system basic enhancer requests and to try and lick it relook at that and see do should we really be dropping the base map to try and get the transformation list a little more accurate well I'm sure that would be one thing that would show up in like what's new by the way we've changed this you make your transformation may have changed if you drop base Maps okay so I was able to find where the you can put up the warning on so if you go to the Pro options and you select under applications select map scene there's a settings set default options for new maps and new scenes so here you can specify some stuff but one ones that I can I want to show you is like here under the spatial reference usually you use the spatial reference of the first operational layer so when you create a new map and you first at the first layer besides the base map the the coordinate system of your map is going to switch to that coordinate system you can also specify that you always want to have particular coordinate system so here's the option you select this option and you will specify to you and here is this warning that you can check in/check on so worn worn if the transformation between geographic coordinate system is required to align data sources correctly so you cannot check that box and you will have that option in your pro yeah I don't think we pick up MapInfo once but I don't know I'm not I'm not sure come get a card for me and I can I can check for you yeah email me and we can check out him okay no I definitely seen people ask about it like on another good resources Stack Exchange anyone use Stack Exchange SEC overflow there's a G is one and and there's all kinds of answered questions there and people ask can ask about stuff like that and someone will know pretty much so yeah anything else yeah oh yeah so that's it so the quarter system data set up yeah yes [Music] right transmissions right yeah then right that's so the comments about having that separate data set up is is risky because a lot of customers won't know to install it or won't realize you need to install it if if a transformation requires data that's in that file we won't actually even show it it won't show up in the list so so you won't have the possibility where you set the transformation thinking it's doing something and not happen and then not have it work so we do we do sort that list and if we would check and make sure is this a usable transformation or not if it's not usable it won't show up as a possibility so at least we can't ruin your data that way but again you're right you might not see that you might not even know that that's a transformation you should use because not showing up in the list yeah it's it's kind of a battle between making the core set up like you know a 25% bigger by adding in the data or more or having a second set up the goal was actually maybe even even the data that's in the core set up because there's a bunch of data there as well as move that out into the secondary set up like move everything out I know one of my colleagues who works on the server side thinks that it should be required set up like you install server it immediately pings over it makes you like basically opt out of installing it instead of an opt-in also with a current version of Pro like I notice when you do the update and if you have the coordinate system set up already there is going to ping you and then say like hey I see you have a coordinate system set up do you want to install the latest one as well and it's kind of like you kind of query you and like hey then you can just hit it's going to download it again and you can install it so if you already have it is going to kind of pick it up and update it with your the same time I noticed that yeah so I'll talk to them I'll talk to the the groups that involved in that and again if there's ways we can kind of bring it more to the forefront that we need to do something you need to do yeah yeah well thank you guys so much for coming really appreciate it thank you