It would be great to figure out how to upload larger files to get the 1' EGM2008.

It is almost half a GB. I'll see if I can host it somewhere and download it in the notebook without it being an attached file. But the download will take time for sure and I'm guessing the computations will take a potentially very long time to do in the browser. Standby I'll get the file working.

Try downloading and running the whole notebook locally. Very neat how Observable packages up the whole runtime. That might be one way to make use of a huge file and run the notebook locally. I'm investigating ways to make use of EGM2008-1

I could figure out how to get the initial value above plotted onto this map.

csv parsing expects columns for first row

Not sure what you want in this section. I'll leave it alone for you to walk folks through things.

I'm bringing back a few of the calculations I made that I had so I can validate the part of the calculation that is not in your notebook

My bad!

I added in the cubic parameter so the checkbox input impacts the calculations. Was defaulting to false/off for cubic interp before.

added current date to the end of the file output string

I'm thinking I will figure out how to print a comment above the header with date acquired, geoid used, and interpolation method.

date string is not working for the file download. I think it has to do with the continually updating nature of Daate(now)

Write out the format you want the date in and I'll make it happen. D3 has excellent d3 time formatting and parsing library at our fingertips.

I would make it black and red instead of using green. Doesn't show up as well as green.

Will need to think about contact

I agree it was a bit clunky! I recoded the table of contents to only take up two lines (see above). What do you think?

I republished... perhaps now you can see it?

I'm going to work on this

I need to edit the longitudes to allow for longitudes up to 360, or note that the longitudes should be +/-180

The projection library being used here is going to expect the +-180 interval. I'd recommend a note and if necessary we implement a function that transforms values outside the interval to the corresponding values they should be in the [0, 360] interval.

I was wrong! It already corrects for the +-180 and 0-360 - sorry for the false alarm!

I am not sure. This is one I can investigate. Perhaps Brooks has a clue?

NOTE: this starts to choke on large CSV files, e.g., ~1M rows (see: https://earthscopeconsortium.atlassian.net/browse/DH-1003). It would be good to explore: 1) Better warning messages about large files. 2) other methods of loading large user input data sets, like chunking/streaming, local browser Blobs/File, Shape Files, etc. See: https://observablehq.com/@alandelip/file-loading-techniques https://developer.mozilla.org/en-US/docs/Web/API/FileReader 3) We should look at trying to setup this calculator server side (to also be used as a web service) to perform these calculations. The old Geoid Height Calculator ran server side and could be invoked like a web service.

Plz change "elevation" to "ellipsoid height"

Sync text between below text box and here, you are collecting Longitude,Latitude,Ellipsoid Height not Latitude,Longitude,Ellipsoid Height

Based upon map, are Latitude and Longitude columns labels mislabeled/swapped?

Yup!

Looks like you fixed map plot, it looks more like it should (https://upload.wikimedia.org/wikipedia/commons/3/3b/Earth_Gravitational_Model_1996.png), 90 deg rotated then before. Numbers in the first column of the table are Longitudes not Latitudes based upon markers on the map. Relabel the first column