Hi all, Does anyone have info (or a list) on what datum and projection aliases gdal (and by extension qgis) uses to identify coordinate systems as written in .ers files?

E.g. the below .ers coordinate system does not read into qgis as EPSG: 2393, instead it comes in as a custom projection, which I would like to fix.

Datum = "FINKKJ" Projection = "TMFIN3"

Cheers.

Just watched with my kids, they talked about and used the phrase “route optimization”! How can you deliver the presents to this neighborhood efficiently? Start em young, GIS is the answer!

Hi all! I work at a tech startup and am new to the GIS world. I'm looking for the best resources/courses to learn GIS fundamentals and also put together a brief survey to try and get some feedback on geospatial pain points/challenges. My startup is building data management tools and trying to get more insight into the geospatial world :)

I have an existing survey, with a related parent and child layer, this survey feeds into an experience builder published in Portal. I want to change the schema of the survey by adding several fields, easy enough. When I go to publish, Connect just hangs at the adding field part and just loads forever.

I think I’ve narrowed down the issue to a joined feature layer view created from the survey feature class in AGOL, this view is used for several widgets in experience builder. Before deleting the joined view and breaking my dashboard. I was wondering if anyone could confirm if this the cause of my publishing issues.

I have a BS in Psychology and I’m currently working at a college. I thought I’d give GIS a try since I have a tuition waiver and a friend who makes a great living from a career in GIS.

My professor told me today that this is usually a supplemental certificate, and wasn’t sure well those two degrees would transfer into a job.

I could go a lot of different ways career wise (masters in higher ed, a second BS in manufacturing, etc) so I’m feeling pretty uncertain at the moment.

If I do continue, then I would hopefully land an internship in the summer that would make me a much more desirable candidate.

Do y’all think this would be enough to be knowledgeable/competitive in the job market? Do you know anyone with unique career histories who have careers in GIS?

Yesterday, my ArcGIS Pro stopped opening existing projects. Sometimes it would give an unhelpful "failed to open project" error message, sometimes it hung. But none of my old projects would open. I went searching for solutions and found this: https://community.esri.com/t5/arcgis-pro-questions/arc-pro-project-will-not-open-and-is-hung/m-p/443703/highlight/true#M19564

Renaming my AppData/Local/Esri and AppData/Roaming/Esri folders worked - for a day. This afternoon, I got back from lunch and hit the same problem again. Which is very annoying - I had to re-import all my ribbon customizations. I would rather not have to do this every day. Or more often - it's broken again as I write this.

Can ribbon customizations (I just had one - a tab that opened when a map frame was Activated in a layout, something I do a lot) really permanently break my setup? Do I need to not ever customize the so-customizeable UI? Or is there a different cause that I need to fix? The thread above mentions sync with Dropbox, but I don't think that's the case here - my projects are stored on a network drive that I don't think is synced with any cloud.

Hello ! I've been working helpdesk at a Law Firm for about a year but I realized IT is not my passion but I still want to work in tech but also in the envoirnmental sector as im very passionate about conservation and the envoirnment. I've started learning QGIS( cant afford ArchGIS) & SQL. Is there anything else I should be learning ? Has anyone every gotta a GIS job without going to college/uni ? I want to post a couple projects to GIT and then apply for some internships.

Thank you !

Do I really have to remove all the attribute rules associated with a feature layer just so I can increase the character limit in 1 field??? It's branch versioned. I can't add a new field without replacing the service and I really really don't want to do that.

Im new to drone work but have worked alongside some persons doing RTK footprint work for various locations. Typically its a lot of marking on the asphalt etc etc that we take. Sometimes its very small embedded lights other times its raised lights. We manually walk over and take their location. Requirement is usually < 10-20cm level accuracy requirement

Would this be possible in a literal fraction of the time with an RTK drone and photogrammetry(or another method using a drone).

Anywhere I can see the output of a drone dataset / example dataset to visualise in qgis or anything? Is it similar to point/line/poly layers I would import into a GIS software?

What makes it different from using good maps or street maps? Why does NGA prefer it?

I’m an Earth Systems Science major, I was going to go for my BS in geology until I did the NCAS program for NASA and interviewed for a NASA Develop position (which I believe I bombed ugh). I’ve known since August I want to work with GIS data and RS. I have no experience. I am doing ESRIs MOOCs, done a tiny bit of nasa ARSET training, and NOAA QGIS tutorials. I realized quickly I need to learn python, but I have zero coding experience.

I’m just feeling overwhelmed with where to start and beginner friendly trainings. The professor for GIS at my small CC is out on sabbatical until next Fall so I cannot take coursework yet to explore it that way.

Any recommendations on what to learn first and free open source programs? I’m doing a ton of different trainings and tutorials but feeling I’m missing the computer science side of it (not sure how much of that is needed).

How did you get into GIS/RS? What does a day of your GIS/RS work look like?

Hey group, I am working on a project in which I am trying to find data/shapefiles for the state of Victoria in Australia. I am looking for vegetation type map/shapefile, topography, any known locations of aboriginal tribes and any past wildfire data. It is proving to be very difficult to find data and shape files for these things, where something actually exists or I don't need to pay for it. Am I looking in the wrong places, and where would be better to look? does this data actually exist?

Note: most of the time when I search for things, I am guided to Australian Census/Statistic sites and the Land.vic site, which has a lot of good avenues but I can't access anything.

Any help or thoughts are appreciated!

I have been a GIS Analyst/Specialist for the past 18 + years. I feel when it comes to ESRI/Pro I can “figure it out.” However, after over the years I have realized I could use more seasoning on the IT side of GIS.

I am particularly intersted in learning SQL, improving my knowledge of programming, Microsoft Server, etc. Does anyone have any reccommendations on coursework I could complete to help aid in this effort?

Hi Everyone!

I have a major issue I've been trying to solve in a project, and I just can't seem to figure out how to solve it.

As a back-end, we have a postGIS database running with a test dataset of about 220.000 points. On top of this, we have mapserver en pg_featureserv as middleware. Both provide in essence the same API: a WFS and OGC-API service. We have optimized mapserver and the postGIS database in the regular way: setting SRID, unique key, spatial index, etc.

Now comes the issue: When I use a regular python GET request on both services for both WFS and OGC API, It pulls all of the data in about 17 seconds.

When we use Qgis however, The request takes around 83 seconds! We have determined this is due to pagination. However, in our mapserver we don't even define a max features (but Qgis still assumes it) and of course, OGC-API makes it mandatory.

We have played around with some settings and actually got the WFS and OGC-API working with a page size of ~50.000 features, which brought the load time for Qgis down to 43 seconds.

Somehow it feels like Qgis doesn't optimally make use of both the WFS and OGC-API for both middleware options, and I can't figure out why it performs so sub-optimal when it comes to pagination.

Moreover: When the provided data is in geoJSON format, Qgis reloads the ENTIRE DATASET when you move your view window!

Oh and one more nail in the coffin: With a direct database query it loads within 1 second.

So all in all: I don't know what to do anymore. Qgis is a staple in my company, and this makes it difficult to implement the nice feeatures OGC-API standards bring. Users won't accept these downsides.

Any help to resolve this is greatly appreciated!

Hi, first post.

First and foremost I am not a GIS expert, I have picked up confidence in using GDAL through requirement and need.

I am trying to convert a DEM GeoTiff to an MBTiles format, I can get it all working fine if I export the image from QGIS using the render image export and then convert. No matter what I have tried I cannot get it to go the same way using just GDAL.

My current output is the file with a large black box around the actual data in this case a lidar image of a valley.

I need to remove the black box before it hits the mbtiles as it gets served onto a custom internal application.

Any ideas would be greatly appreciated!

Thanks

Edit - I should say this is using the CLI but I am extremely proficient in Python and other languages so if that is the route it’s all good.

(also posted to https://gis.stackexchange.com/questions/488480/how-to-efficiently-find-largest-geodesic-circle-centered-in-country-not-touching)

Just for fun, I'm trying to find the largest geodesic circle centered in a country (for example, Chile) that doesn't touch any other country's land. I've found a way to do it, but, because I've "learned GIS" through "AI", I'm worried my entire approach is wrong or inefficient and would like some advice. My method:

• I first downloaded all the country shape files from https://gadm.org/ and put them into a GADM subdirectory

• I then imported them into GRASS using commands like:

v.in.ogr --overwrite -o input=/vsizip/GADM/gadm41_CHL_shp.zip/gadm41_CHL_0.shp output=gadm41_CHL

v.db.dropcolumn gadm41_CHL columns=COUNTRY

since the COUNTRY column would create issues otherwise. The full list of commands I ran is in https://github.com/GroovyJeff/Streaming/tree/main/OffStream/20241204 under "gadm-to-shp.grass"

• I then glued (patched) them into one big 'world' vector map using a command that starts:

v.patch --overwrite -e output=world input=gadm41_ABW,gadm41_AFG,gadm41_AGO,gadm41_AIA,gadm41_ALA,gadm41_ALB,gadm41_AND,gadm41_ARE,gadm41_ARG,gadm41_ARM,gadm41_ASM,gadm41_ATA,gadm41_ATF,gadm41_ATG,gadm41_AUS...

The full command is in https://github.com/GroovyJeff/Streaming/tree/main/OffStream/20241204 under "superpatch.grass"

This did yield some errors which I ignored: I don't think these errors affected my results.

• I then decided to rasterize the maps so I could use r.grow.distance, which may be a fundamental error since I'd have preferred to use the more precise vector maps directly. Other issues with rasterization:

  • I ended up rasterizing at 2048 rows by 4096 columns which is very low resolution (about 10km per pixel). I did try and could use higher resolutions, but r.grow.distance slows down drastically. I understand there's a time-accuracy tradeoff here, but when I get to my preferred resolution of 1 km (21600 rows by 43200 columns), r.grow.distance is painfully slow

  • I used v.to.rast to stay within GRASS, but wanted to use gdal_rasterize since its -at option ensures even the smallest islands are given one pixel. I couldn't find a v.to.rast option to do that. It seems like -d (densify) might work, but I'm converting areas and it won't let me use -d with areas

The commands I used to rasterize Chile and "not Chile" are:

g.region n=90 s=-90 e=180 w=-180 rows=4096 cols=8192

v.to.rast use=attr attr=cat input=world where='GID_0 NOT IN ("CHL")' output=notCHL --overwrite

v.to.rast type=point,line,boundary,area use=attr attr=cat input=gadm41_CHL output=justCHL --overwrite

• I then used r.grow.distance to compute the nearest distance to a non-Chilean point:

r.grow.distance -m --overwrite input=notCHL distance=notCHLDistance metric=geodesic

• This yields the furthest distance from non-Chilean countries, but the maximum isn't itself guaranteed to be in Chile (and, in fact, is not). Therefore, we intersect with Chile:

r.mapcalc --overwrite "CHLDist = if(justCHL > 0, notCHLDistance, 0)"

• We can then use r.stats to find the point in Chile that's furthest from not Chile:

r.stats -1gn CHLDist | sort -k3nr | head

The result, -109.27001953125 -27.09228515625 1930072.156897064 is unsurprisingly on the remote Pascua Island of Chile.

Could I have done this more efficiently, more accurately, or better in some other way?

I've also tried doing something similar using the Julia programming language, but haven't found a notably better non-GRASS solution.

Hello All,

I wanted to see what other organizations are doing to help keep track of data collection and the Editor Tracking standard fields. Editor Tracking utilizes the UTC time and records as such. However, when viewing the layer for the created_date, last_edited_date, it is obviously different than my time-zone. How does your organization manage those fields to accurately show the local time-zone when the new record is created?

I'm working on a database where we store trips users have made. The trips are stored in a PostGIS database with 2 million entries, structured as follows:

• id
• start_point (geometry(Point, 4326))
• end_point (geometry(Point, 4326))
• route (geometry(LineString, 4326))

I have generated a vector tile from the routes by exporting them as GeoJSON and using Tippecanoe to convert it to vector tiles. But all routes appear the same.

I want to style the routes based on their frequency, with more frequently used routes displayed in darker colors. Additionally, I would like to create a heat map of the start points, showing areas of higher density in warmer colors, and combine this with the styled routes on the same map.

What i need is someone to point me in the right direction, what i tools or concepts that i need to look for to make this happen? below is an example similar to what I'm trying to make i found online

https://preview.redd.it/yuf74mf3ou4e1.png?width=4000&format=png&auto=webp&s=879d8121bf2bb4ccc101a19eca1ed60368bc7464

I resize the layout after adding all the map frames, usually around 7. They have to be at a specific scale and look evenly placed. So I use layout guides with 0.5 inch space between maps. After I add all the maps I need to resize the layout to have a 0.5 inch buffer all the way around, but the guides move with the layout resize. Resize elements is not checked because I don't want the maps to rescale to an odd scale, they need to stay at 1:100k (for example). Any ideas? Searching the internet has not helped.

I am curious to know if anyone else has such a limited number of pre-built styles in AGOL as myself (or our organization has). It seems odd that the default ESRI types would include more than just a few basic styles.

I would like to expand our style libraries to match our organization-defined colors by our marketing and communications department. I am curious if anyone else has gone through a similar effort in their org? If so, what should I consider going into this?

Thanks in advance!

https://preview.redd.it/ui8igqvxdu4e1.png?width=409&format=png&auto=webp&s=74e54c0e212da6ff4f76d283d5853f046174446d

Hi, I'm in the process of spinning up my Mapproxy instance in order to have a more central way to serve my own maps. My own maps are either XYZ tiles (tiles meant to be displayed as OSM layers, usually in 256x256px and start from NW), and in one case I want to use Mapproxy as a WMS -> WMTS/XYZ relay.

I am running Mapproxy as a docker container (ghcr.io/mapproxy/mapproxy/mapproxy:3.1.3-alpine-nginx).

A few questions:

• To avoid ending up with millions of tiles stored on drive, I want to use the sqlite cache type. For most of my tiles, the cache should be permanent (easy), and for some I want a TTL of 4 weeks. I understand I need to manually start (or script the execution) of a seed job with refresh_before or remove_before? What would be a clean way to do this?
• I have a number of tile sources that I would like to merge. I've tried having multiple sources in a same cache entry, but that results in just... nothing, at least when I try to load the tiles via WMTS/XYZ.
• Some tiles that have a XYZ source show up fine when loaded as WMTS/XYZ. However when I try to display them in QGIS via WMS, each tile is seemingly inverted vertically. I'm confused as to how to fix this.
• Can I easily create a coverage BBOX from a list of available XYZ tile files?

Thank you.

Hello, i am studying a masters in GIS and we have this assignment where your supposed to create network manually, i have tried it but i feel like i am doing something wrong.

Hello!

Anyone here tries using the MOLUSCE plugin of QGIS to predict future land cover? Everytime I set the sampling to "random", the plugin just stops responding. What maybe the cause and what could be a possible solution to this?

Also, MOLUSCE only requires that the geometry and extent are the same (same raster extent and pixel size). Do the rasters need to be of same type as well? (All must be float32? Or float 64?)

Thank you very much.

I’m an urban planner, and a hobbyist cartographer. Been doing a lot of solo trips this year. Just picking a place in the US and seeing any state parks along the way. Never been big on souvenirs, so I’ve been geotagging locations along my way. Thinking of making some maps of my trips and hanging them up, anyone have any experience on a good place to print them out. I could use a plotter at my job for anything big, but I’m looking for a good place preferably online to order thick paper prints.

Hello all, I have degree in Business Analytics. I had learned and did data analytics projects (on Python mostly). I came to realize that I don’t like business domain in general and want to find other domain. I briefly done some research about GIS and find it more interesting. My question is Can someone didn’t have degrees in Geography self-taught GIS and find a job in the industry? If so, what are your advices? thank you so much in advance. Sorry I feel like i’m so amateur here

I'm not sure what's going on, but when I search for the legend in the command search, I am unable to click on the legend (it's in a gray color). If someone knows how to fix this, that would be greatly appreciated.

I'm using this code in gee and using whole Banggladesh map as an area of interest.

Code :

var collection = ee.ImageCollection('COPERNICUS/S5P/OFFL/L3_O3') .select('O3_column_number_density') .filterDate('2023-01-01', '2023-12-31') .mean() .clip(table);

var band_viz = { min: 0.12, max: 0.15, palette: ['black', 'blue', 'purple', 'cyan', 'green', 'yellow', 'red'] };

Map.addLayer(collection, band_viz, 'Ozone Concentration'); Map.centerObject(table, 10);

Export.image.toDrive({ image: collection, description: 'Sentinel5P_Ozone_2023', scale: 10000, region: table.geometry(), fileFormat: 'GeoTIFF', crs: 'EPSG:4326' });

but when I run it to export the geotiff file it says, 'Request payload size exceeds the limit: 10485760 bytes' How can I solve it?