New USGS 24k Legacy Topo Map

Boyd

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Putting the finishing touches on this new map and hope to have it online in the next day or so. It's a "curated collection" of 2,672 USGS 24k (7.5 minute) quadrangles from the USGS Historical Topographic Map Collection, newly downloaded and stitched together (about 3.5 million map tiles). In most cases I have chosen the newest version of each quad, but sometimes it wasn't that simple and I used older versions for a variety of reasons.

For my small USGS Pines topo, I did color matching between quads with Photoshop. That isn't practical for such a large map, so there's a lot of color variation. At first this bothered me, but I gradually learned to "embrace the diversity". Many of the quads date from the 1940's (were never updated since then), even more from the 1950's. The largest group is probably from the 1960's, there are very few from the 1970's or 80's. Then a final push to update in the 1990's - very few are newer than 1999.

It was processed at 2.4-meter resolution which preserves the full detail of the original USGS scans. The map has full coverage of NJ, PA, DE, MD, CT, RI and MA with large portions of NY, VA and WV. I plan to expand map coverage to a much larger area over time.

coverage.png


As you zoom out, the view switches to the USGS 100k Topo at level 13, then the USGS 250k Topo at levels 12 and 11. Levels 6 through 10 show a simple basemap I made myself, like the little one above.

This map replaces my older "1999 in the Pines" topo, there are some small differences but it's basically the same. It also replaces the NJGIN 24k topo and the PASDA 24k topo - the new map will load much faster and has seamless coverage of the same areas at much higher quality. For example...

PASDA 24k Topo
pasda.png



NJGIN 24k Topo
njgin.png


New USGS 24k Legacy Topo
legacy.png


For the sake of comparison, this is the topo at NJPB Maps - it only has half of the resolution, so this is as far as you can zoom in.

NJPB Topo
njpb.png


The "heavy lifting" is done, now I have a few details to fix plus some code and documentation to write, so it's coming soon. After uploading/installing the new map, any existing links/bookmarks to the NJGIN topo, PASDA topo and my Pines topo will automatically redirect to the new map and an alert will be displayed; the old maps will no longer appear in the menu. Unfortunately, if any of these are in your "favorite maps" menu, they will be automatically removed and you'll need to manually add the new map.

I'll post an update to the site problems thread when the update/installation process begins.
 
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Boyd

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The new map is available now, you may need to reload/refresh your browser to see it. Here's an example

https://boydsmaps.com/#16.00/41.099575/-74.968159/legacy24k/0.00/0.00

The map should appear at the top of the menu if your are using the default "local maps" mapset

Screen Shot 2022-08-28 at 6.41.16 PM.png


FWIW, here's the distribution of quadrangles by decade. The maps that are newer than 2010 are digital "US Topo" maps that I used where (for whatever reason) no historical version was available.

legacy24k_info.png
 

Boyd

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Sorry for the confusion Bob, just returned from a night time walk. :) Click the gear icon at the top left of the maps menu

0.png


Now click the gear icon in the mapsets window

1.png


Click Edit Favorites

2.png


The old topo's were automatically deleted from your favorites, sorry it just involved too much new code to do a more graceful modification of the favorites menu. If you want to add the new legacy topo, click the Add Map button.

3.png



It should be the first item on the list, just click the button to add it.

4.png


Be sure to click the Save button when you're done. Just closing the window without saving will cancel the change to the menu.
 

Boyd

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That is a cache issue. For some reason it seems that your MS Edge browser really likes to hold onto old data. Awhile ago I told you how to backup your data and you said you saved it in your downloads folder. If you clear site data, that will allow you to easily restore your old favorites, then you can add the new map.

Seems to me that the last time you cleared all the site data, your favorites were not affected anyway however.
 

bobpbx

Piney
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Pines; Bamber area
That is a cache issue. For some reason it seems that your MS Edge browser really likes to hold onto old data. Awhile ago I told you how to backup your data and you said you saved it in your downloads folder. If you clear site data, that will allow you to easily restore your old favorites, then you can add the new map.

Seems to me that the last time you cleared all the site data, your favorites were not affected anyway however.
Using your tools, about an hour ago I did a backup. Maybe tomorrow I'll do a reset, see what happens.
 
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Boyd

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If you wait long enough, it should just take care of itself, the browser will eventually download the new code. Might take a few days for that however.

Here's something interesting. It seems the USGS hardly updated the topos at all between 1970 and 1990. Maybe they were updating other maps out West or something? For some reason, Southern Maryland was never properly mapped. They did some pretty incomplete quads in the 1940's and never updated them. But during the 1970's, they took some pretty bad (by current standards) aerial photographs and added features to them. I suppose that was easier than drafting a "real" map.

You can see examples of these if you look at the ArcGIS topo's here at NJPB, such as the town of "Wango" :D

https://maps.njpinebarrens.com/#lat=38.32147439608695&lng=-75.45011748114402&z=15&type=topo&gpx=

I don't care for these - and there are quite a lot in MD and WV. ArcGIS (National Geographic) used them, since they are newer but I used the old 1940's topo maps instead. I wanted everthing to look like a topo map. This is the same location:

https://boydsmaps.com/#15.00/38.321753/-75.450185/legacy24k/0.00/0.00
 
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Boyd

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The USGS calls these oddities "Orthophotomaps". I wonder exactly what they were thinking? Was it just an easy way to make an updated map, or did they have some plan to create a new standard? A quick Google search doesn't find anything about this.

Screen Shot 2022-08-29 at 9.47.24 AM.png
 
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bobpbx

Piney
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The USGS calls these oddities "Orthophotomaps". I wonder exactly what they were thinking? Was it just an easy way to make an updated map, or did they have some plan to create a new standard? A quick Google search doesn't find anything about this.

View attachment 18062
Maybe the person who designed it was the one who redid the NOAA site. I'm on the verge of never forgiving them for that.
 
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bobpbx

Piney
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Pines; Bamber area
Outstanding work Boyd. It did show up enventually, and very timely as I needed to see it for a report I'm doing. Very clear and crisp.

Thank you for your efforts.
 
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Boyd

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Glad that it works and you're finding it useful!

I hadn't planned it, but on an impulse I started making a map of the same region with c. 1900 topo maps (using the oldest map I can find for each quad). How hard could that be?... there are "only" about 700 maps to download and process. Of course, nothing is ever that easy. A number of maps just aren't available from the USGS, have been finding them elsewhere and georeferencing myself. Others are named differently from the USGS metadata, which is confusing. Lots of typo's in the USGS metadata shapefile that I'm using as an index, this is a problem because I wrote some software to process the maps and it doesn't recognize the files if the spelling is wrong. :bang:

Anyway, I'm finding some cool old maps and am about 25% done, which isn't bad for two days work. With a little luck, this might be finished around Labor Day. :)
 
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Boyd

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The 24k Legacy Topo has just been updated and now covers the whole Northeast US region with all of Connecticut, Delaware, Maine, Maryland, Massachussets, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island and Vermont and partial coverage of Virginia and West Virginia. My rather crude basemap has also been replaced with the USGS National Map Topo basemap at zoom levels 5 through 9, which should make it easier to identify/find places before zooming in.

basemap.png


There are a total of 4,225 quadrangles and here's a breakdown by decade. Again, I have used the newest available maps unless there were quality issues. There were a bunch of quads that just weren't anywhere in the archives and I used the digital US Topo 24k quads for these, mostly from the period 2019-2021.

quad_info.png


But the big surprise was, the Adirondack Mountains don't appear to have ever been mapped at 1:24000 scale (or at least they aren't in the archives). Instead, they were mapped at 1:25000 scale during the 1980's and 1990's. They're slightly lower resolution, although you probably won't notice. These were a lot of extra work because they also cover twice the area of the 24k maps (7.5 minutes x 15 minutes), so I had to process them all "by hand" instead of using the software I wrote. There was also no documentation that I could find for these, so it was all a bit of a frustrating puzzle!

But the unusual thing is that the metric system was used on all of these maps (hence the 1:25000 scale). It seems that the USGS was well along a path to change all their maps to the metric system in the 1980's. This is very confusing however, since after cropping the map collar, there's no indication that these quads use the metric system. Elevation contours are labelled in meters on all of these maps, so check the elevation display at the top left of the screen, it will always show the elevation in feet. These 25k maps are shown in pink below.

25k_quads.png


Here's what the paper maps looked like. Don't recall seeing any of these myself, but they are from the same series as the 100k metric maps that were released in the 1980's (like the Hammonton Quad that I used to carry in my pocket when wandering around the Pines in the 90's)

metric.png


In total, 24k Legacy Topo is now about 60gb and contains around 8 million tiles. Now I need to decide what to do next. I may expand the 62k Historic Topo to match this same coverage, or maybe just continue expanding the 24k map South and West to include all of Virginia and West Virginia.... "So many maps, so little time". :D
 
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Boyd

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Just completed another big update to the 24k Legacy Topo, it now includes full coverage of Virgina and West Virginia plus partial coverage of Kentucky, Tennessee, Ohio and Michigan. There are 1442 new quadrangles - about two million new map tiles. Here's the full coverage area.

coverage.png


But once again, your browser may still cache the old map data and refuse to show the new coverage area. Clearing the browser cache should fix this. Here are a couple links to new sections of the map FWIW.

Ohio State University in Columbus:
https://boydsmaps.com/#16.00/40.000173/-83.024589/legacy24k/0.00/0.00

Appalachian Trail, Damascus Virginia
https://boydsmaps.com/#16.00/36.635889/-81.777504/legacy24k/0.00/0.00
 
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Boyd

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Good question, and a little hard to say. I used a commercial web statistics software package to analyze use up through this summer and IIRC there were around 30-40 people/day. However, I got rid of that software in September because I didn't like the privacy aspects - it put cookies on your computer. That is all gone now and I'm using some open source software that just analyzes the web server log file without storing anything on the user's computer. So it's hard to know who a "person" is, I can just identify unique IP addresses. And with VPN's and Apple's new iCloud relay feature, IP addresses don't tell you as much as they used to.

Anyway, so far today, there have been 78 unique IP addresses used. I look more at the amount of map data that is served. That has been fairly constant over the past couple months at around 200 to 300 MB/day. But recently it has spiked up considerably, coming closer to 1 GB/for the past week or so - 450MB have been served so far today (since 7:00AM). I think the "Sync" app is one reason for the additional data use, since you are viewing two maps at once there. Also, 3d maps use twice as much data.

I only track data on the maps that are hosted on my server. If you use the NJGIN 2007 aerials (for example) that is not part of my statistics, since the files are being served by NJGIN. So, its possible (even likely) there are more people who are using the site but not using maps hosted on my server.
 
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