TransDEM Forum

Here's 2 samples of the DEM on the Delaware River (1/9 arc sec) where a channel was dug near the U.S. Steel plant in Fairless Hills, PA. The raster map is the NOAA nautical chart for that area. I don't think I've ever seen a raster map match up with a DEM so nicely!

http://i66.tinypic.com/2dkb79f ...

As it turns out, the 1/9 arc sec data just covers what I need. I redid my selection area and captured more area this time. Thanks for checking it out. When I get something to look at, I'll post a screen shot or two. It is neat seeing the terrain slope down into the bay or ocean and not just end in a ...

Hello again. That "DEM" file is at https://www.ngdc.noaa.gov/thredds/fileServer/regional/atlantic_city_13_mhw_2007.nc

According to the web page ( https://www.ncei.noaa.gov/metadata/geoportal/rest/metadata/item/gov.noaa.ngdc.mgg.dem:595/html ), the file is in format netCDF (Version: 4 Classic) and ...

Thanks, geophil. And thanks for the explanation of map tiles. The reverse order of column and row had me puzzled for a bit too.

I had found a recent "DEM" of the ocean in that area, but TransDEM didn't know what to do with it. I'm at work now, but I think the file had an .nc or .mc extension ...

Well, I gave myself a headache today figuring this out, but it works! :geek:

After ripping apart their examples and URLs, I set up my tile service like this:

http://i64.tinypic.com/2uo6sug.jpg

Here's it in action:

http://i66.tinypic.com/o6jnmx.jpg
(I think North is rarely up in nautical ...

Thanks for checking it out, geophil!

I searched around on their site some more yesterday. I found some APIs for ArcGIS and Google Maps. I really thought I had a fish on the line when I found their PDFs! Alas, they are not geoPDFs. I waded in and did some manual georeferencing with points, which is ...

Good Afternoon,

Has any work been done with Nautical Charts and TransDEM? Living in the US (New Jersey), I noticed today that the NOAA has a tile service at:

https://tileservice.charts.noaa.gov/

I wonder how big of a step is it to get the above as a tile service in TransDEM? I looked around the ...

Your explanation of the Sta 0 to Sta 52+80 makes sense. I never know what measurements those 52+80 were in, but if what you say is correct, the length would be 3484.8 feet or 0.66 mile. I got those numbers from a conversion app on my iPhone. And I guess that is the distance along the mainline track ...

Hi Jerker,

Nothing new to offer, but your method is exactly what I did several years ago with "Sanborn Maps":

http://guides.libraries.psu.edu/sanbornmaps

Not all are available online, but here's an area in Trenton, NJ from 1890 that is:

https://www.loc.gov/resource/g3814tm.g3814tm_g056391890 ...

Unfortunately, at least in the geographical areas I've seen, the farther back in time you go in Google Earth, the resolution decreases and the imagery becomes more fuzzy and sometimes the color becomes gray scale. I guess it depends if you want it for ground cover or just a template for placing ...