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22 votes
Accepted

Are there duplicate Zip codes in the US?

There are no duplicate ZIP Codes. There are some ZIP Codes that are multi-part polygons, but those polygons are usually adjacent. Source: I manage/update ZIP Codes for the USPS
Maksim's user avatar
  • 6,926
17 votes
Accepted

Why is there no state with code "03" (among other missing numbers)?

These are Federal Information Processing Standard (FIPS) state codes, and the ones you mention are missing because, from the wiki: "certain numeric codes "are reserved for possible future use in ...
Kartograaf's user avatar
  • 2,927
13 votes

Seeking shapefile of city boundaries in US?

Getting the Data You can acquire US Census Place Data, which includes cities, here. For instance, Rhode Island's 2017 Place Data is available here. For ease of bulk downloading, the full list 2017 ...
Richard's user avatar
  • 1,831
12 votes
Accepted

Meaning of dash in house address number in USA?

In my experience, it usually means what you think it means: a range of address numbers. I've also seen it used as a way of writing an apartment or suite number, so 136-39 37 AVE would be 136 37th Ave, ...
Dan C's user avatar
  • 12.2k
11 votes

Finding footprint data for US buildings?

Microsoft just open sourced 124,885,597 million computer generated building footprints in all 50 US states https://github.com/Microsoft/USBuildingFootprints
chadwilcomb's user avatar
9 votes

Determining which US zipcodes map to more than one state or more than one city?

2016 TIGER Data with PostGIS As a special caveat, ZCTA data isn't USPS Zip Codes. It's an approximation of it. USPS Zip Codes are really horrible and not useful except to approximate. Everyone, ...
Evan Carroll's user avatar
  • 7,091
8 votes
Accepted

Why recommended transformation is not the most accurate in QGIS?

How is this default picked by QGIS? QGIS makes a query to PROJ libraries to obtain the list of possible transformations between two reference frames or geodetic datums. Sorting algorithm is ...
Gabriel De Luca's user avatar
7 votes
Accepted

Identify this state outline file

It looks like it could be from the Project Linework website. Specifically, the "Angular" or "Twenty Seventy" datasets.
cl3's user avatar
  • 1,936
7 votes

Choosing map projections specifically for San Francisco Bay Area?

There are many coordinate reference systems (CRS) which could be used for the San Francisco area depending on what you are doing with the data. UTM zone 10 North is designed for medium scale purposes ...
mkennedy's user avatar
  • 18.9k
7 votes
Accepted

Choosing CRS for Chicago, Illinois

As you already hint at in your question, there is really no "best" projection. What you use depends on the requirements of your project and how you want to display spatial data. That said, the most ...
lambertj's user avatar
  • 3,037
6 votes
Accepted

Getting 8 digit watersheds for USA

I was looking at this dataset myself today, I opted to send an e-mail and the data layers that I needed. I'll see if they hold true to the 1-2 business days. However, I also came across this site - ...
whyzar's user avatar
  • 12.1k
6 votes

Using one CRS for an entire US state?

Look for EPSG:3968, NAD83 / Virginia Lambert. There are variants using different geographic coordinate reference systems (CRS) like 3969 on NAD83 HARN, 3970 on NAD83 NSRS2007, and 6591 on NAD83 (2011)....
mkennedy's user avatar
  • 18.9k
6 votes
Accepted

Converting xy point to lat/long

I tried several coordinate systems for Florida and the various State Plane Florida East zone but the coordinates just didn't seem to fit. Google kept finding the address in Hempstead, NY, so I tried ...
mkennedy's user avatar
  • 18.9k
5 votes

Why are Galileo satellites inaccessible in USA?

This is not a technical reason (Gallileo satellite fly above the US and could work above the US like in other places of the world), but this is a trade law issue, as stated in "inside GNSS": ...in ...
radouxju's user avatar
  • 49.7k
5 votes

Why are Galileo satellites inaccessible in USA?

On November 15, 2018 the FCC approved the waiver mentioned in the answer by @radouxju to allow the use of the Galileo E1 and E5 signals within the US. See https://www.fcc.gov/document/fcc-approves-...
NickW's user avatar
  • 51
5 votes

Which coordinate system is the best for a distances from whole USA?

Your best workflow may depend on whether you want "as the crow flies" distances or "via road" distances. For the latter, you would need to have a line data layer. For the "as the crow flies", you ...
mkennedy's user avatar
  • 18.9k
5 votes
Accepted

Is the ESRI ArcGIS definition of California Albers projection using units of feet correct?

Disclosure: I work for Esri as a product engineer focusing on coordinate reference systems and transformations. Disclosure 2: I'm on the subcommittee that maintains the EPSG registry. You are ...
mkennedy's user avatar
  • 18.9k
5 votes

Changing pixel size of georeferenced historical map

The original scan of the map can be found here: http://legacy.lib.utexas.edu/maps/ams/india/nc-43-03.jpg I have enlarged the details on central bottom of the map The CRS of the blue lines can be ...
Hans Erren's user avatar
  • 1,170
4 votes

Source for GeoJSON data for the US

I've translated most of the Census Cartography files to GeoJSON for your convenience: https://github.com/loganpowell/census-geojson
Logan Powell's user avatar
4 votes

US boundaries from 1780 map

There is an atlas of historical boundaries which features the data you're looking for. You can find the data in different formats on the bottom of the linked page.
karpfen's user avatar
  • 2,297
4 votes
Accepted

Converting PLUTO coordinate reference system in QGIS?

I just tested with MNMapPLUTO.shp from http://www1.nyc.gov/assets/planning/download/zip/data-maps/open-data/qn_mappluto_16v1.zip in QGIS 2.16 and 2.17 and I cannot reproduce your issue. Open ...
underdark's user avatar
  • 84.2k
4 votes

Seeking contour data for Oregon?

You can make you own with a really straightforward workflow and a couple of free gdal tools 1) download the SRTM data from http://dwtkns.com/srtm/ 2) merge multiple tifs into one gdal_merge.py -...
CitizenFish's user avatar
4 votes

Getting 8 digit watersheds for USA

The National Hydrography Dataset contains the Watershed Boundary Dataset, which contains 8-digit watersheds (also 2,4,6,10,12,14, and 16-digit where available) for every state in the USA. The high-...
Dan C's user avatar
  • 12.2k
4 votes
Accepted

What projection is being used in this dataset?

Latitude and Longitude being used strongly suggests that these are not projected coordinates. The documentation of the fields says the ones without trailing S are "formatted" while the ones with an ...
bugmenot123's user avatar
  • 10.9k
4 votes

Meaning of dash in house address number in USA?

Some localities use a grid-based addressing scheme, for example Fair Lawn, NJ: https://en.wikipedia.org/wiki/Fair_Lawn,_New_Jersey#Grid-based_address_system Fair Lawn uses a street address ...
Joe's user avatar
  • 141
4 votes
Accepted

Working around US Census site blocking of IP addresses?

To simplify the download on multiple machines, you can use more advanced downloading tool (such as aria2c) that supports resume etc., and have a script continuously download the dataset from a file of ...
laser's user avatar
  • 966
4 votes

Using one CRS for an entire US state?

... or do I have to split the data up into North and South? For this part of the question, the state plane coordinate system divides a (larger) state into multiple zones in order to limit the map ...
tinlyx's user avatar
  • 11.1k
4 votes

Where can I find the official data of all cities in the United States?

Try the US census data. For example: https://www.census.gov/data/tables/2017/demo/popest/total-cities-and-towns.html#tables Each state will have its own GIS data of cities (and other political ...
Kate's user avatar
  • 41
4 votes
Accepted

What coordinate notation is this?

You can use the 'Calculate Geometry Attributes' tool to accomplish this. The important part is setting a coordinate system appropriately. Your source coordinate is a projected coordinate system (...
Anna Forrest's user avatar
4 votes

fttx network design in QGIS: how to calculate distance to network backbone or another connected node, whichever is closer

An algorithmic approach. Implementation in QGIS below - if you create it as model, you can re-run it to create the result automatically. This is how the output looks like after the steps that follow ...
Babel's user avatar
  • 72.1k

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