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#51
General Discussion / Minnesota topo
Last post by mstl - July 19, 2023, 06:22:14 AM
I can download the Minnesota topo map, but it does not seem to unzip.  Any suggestions?
#52
General Discussion / Re: Old maps from years past?
Last post by Boyd - July 17, 2023, 03:20:46 PM
Old maps of what region? I offer a USGS Historical Topo Map with full coverage of Connecticut, Delaware, Maine, Maryland, Massachussets, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, Virginia and West Virginia with partial coverage of Kentucky, Indiana and Michigan. It was made from the oldest maps that the USGS has in their archives. They started creating topo maps in 1879, the oldest one in this collection is from 1884. It's a composite made from 1,900 separate quadrangles stictched together into a seamless map. More than half of them are over 100 years old. Houses and buildings are shown in some areas but not others.

Use my web app here, it's free, works on any device, there are no ads and no registration.

https://boydsmaps.com/#14.00/42.359875/-71.057564/historic62k/0.00/0.00

I also have a USGS Legacy Topo which covers the same area and consists of the newer 24k topo maps. But these would also qualify as "old maps" because the USGS began winding them down in 1990 and completely phased them out by 2000. I used the newest versions available, but most are still pretty old. There are a total of about 7,500 individual quads in this map, and 4,500 of them are at least 50 years old. The 24k topo maps are pretty good at showing houses and other buildings.

https://boydsmaps.com/#15.00/42.359875/-71.057564/legacy24k/0.00/0.00

Now, I have a number of historical topo maps from the Southern New Jersey region where I live. This one is interesting, it dates back to around 1885. The little trees are not just decorative, they indicate which areas were forested and the type of trees (coniferous or deciduous).

https://boydsmaps.com/#14.00/39.400482/-75.035955/cook/0.00/0.00

I also have topo maps of the same Southern New Jersey region from 1870, 1889, 1890 and 1949. If you go to the link above, just click the map menu and you will see them listed. But these only cover a small area and have a more limited audience.

There are a lot of other map resources on my site, including historical aerial imagery for some areas. New York City has some very cool aerials from 1924, for example

https://boydsmaps.com/#17.00/40.730794/-73.997581/nyc1924/0.00/0.00

New Jersey has aerial imagery from the 1930's covering the whole state

https://boydsmaps.com/#16.00/40.720237/-74.228107/njgin1930/0.00/0.00

There are also aerials of the Jersey Shore from the 1920's

https://boydsmaps.com/#16.00/39.351034/-74.453718/njgin1920/0.00/0.00

If none of these cover the areas you're looking for, you can try the USGS Historical Topo Map Explorer. It will show what historical maps are available for any location in the US, but it's not a "seamless" map like the ones on my site, they are scanned copies of individual paper maps that you can download.

https://livingatlas.arcgis.com/topoexplorer/index.html
#53
General Discussion / Old maps from years past?
Last post by Vipervenom - July 17, 2023, 02:07:18 PM
Wondering if anyone has idea where I might find maps from years ago, something that would show old buildings and houses locations.
#54
Map Making Support / Re: Experiments with LIDAR
Last post by Boyd - July 06, 2023, 12:25:50 PM
Quote from: Boyd on June 07, 2022, 11:45:24 AMBelieve it or not, ten years have passed, I'm still here and still doing "Experiments with LIDAR"!

Another year has passed... still doing "Experiments with LIDAR"  :)  You can also do some "experiments", just click the button with the blue cube on my site to open the Terrain Viewer. You can also link directly to the viewer, for example:

https://boydsmaps.com/terra/#37.823766/-79.914004/-877/1766/1578/0/292/0/2000/775/-2000/56.99999999999999/2/3d/shader40/0/2/z15



The Terrain Viewer takes a "slice" of the map and exports it as a 3d model where you have many options for controlling the appearance.

There are sliders for the XYZ coordinates and intensity of the "sun" (a directional light source). Observe the effect as you move the sliders, the changing lighting will reveal different details in the terrain. Another slider changes the vertical scale of the terrain (vertical exaggeration) in realtime, which can make a big difference in appearance.

You can choose 6 different map types: aerial imagery from NAIP (the National Agriculture Imagery Program)

https://boydsmaps.com/terra/#40.615801/-74.822234/-1273/1059/-2/0/46/0/1000/437/1014/75/2/3d/ortho/0/0/z15




The grayscale option is just a white surface and the shadows create the shading.

https://boydsmaps.com/terra/#41.460554/-71.944232/-676/454/891/0/250/0/0/465/-1577/52/2/3d/grayscale/0/0/z17



The shaders (5, 10, 20 or 40 colors) use my own code to set the color of each pixel based on its position between the minimum and maximum elevation of the map.

Each map consists of 4.2 million elevation samples in a 2048 x 2048 grid. The spacing between samples determines the map resolution and size, the highest resolution has a sample spacing of 4 feet (1.2 meters) and coverage area of about 1.5 x 1.5 miles (about 2.5 km).

https://boydsmaps.com/terra/#39.251821/-76.735124/0/67689/0/0/314/0/-986/600/-986/45/3/2d/shader20/0/0/z17



The viewer uses webGL with the three.js API and the same RGB-encoded elevation dataset as my main web app. I use the MapTalks API to cover an HTML canvas with RGB tiles, then populate an array using elevation values decoded from each pixel's RGB values. That array is then used to create a 3d mesh. For the color shaders, I iterate through the array, creating another HTML canvas where each pixel is colored according to its elevation. That canvas is then mapped onto the 3d mesh.

The detail available in the terrain viewer revealed some major flaws in my original Mid-Atlantic elevation dataset that were not so obvious before. Took quite a bit of troubleshooting to understand the problem, but eventually I found it. The issue was caused by re-sampling artifacts when I exported the RGB elevation tiles with Globalmapper. Using "nearest neighbor" sampling would have fixed the problem, but that is not an option in Globalmapper. Finally, I discovered that exporting my DEM files at the *precise* resolution for each zoom level would prevent Globalmapper from re-sampling.

I ended up re-processing my entire elevation dataset from almost 2 terabytes of uncompressed TIFF source files, producing 9 million 256x256 map tiles.Took around a week of 24/7 processing but made a huge difference in the quality of the 3d views in both the terrain viewer and the main web app.

My next project is expanding the 3d terrain coverage area to include all of New York, Massachussets, New Hampshire, Vermont and Maine, which should be available later in 2023. I've expanded the server to 2 terabytes of disk, so we'll see how much space is left when this is completed!
#55
Using The Maps/Garmin Software / Re: [SOLVED] Lost all routes a...
Last post by TeleBruce - June 26, 2023, 05:10:28 PM
Hello Boyd - Back again with this.

I was wrong.
the solution was much simpler than I thought and it will encourage me to spend a bit more time familiarizing myself with my own GPS!

Loading my backup GPX files into the onboard GPX folder worked fine until I turned the 66i off. Rebooted and all was missing again.

Solution:
1) Connect GPS to the computer
2) computer will show 2 mass storage devices (or in my case with Linux - 2 drives)  Garmin, and 32GB SD card.
3) Check the GPX folder on the SD card. Mine was empty.
4) With the 66i still connected to the computer - Copy all the GPX files from your backup to the GPX folder on your SD card (not internal memory!).
5) When finished, Disconnect the GPS
6) Reboot the GPS
All the files should now load into the onboard memory and be accessible.

I tried rebooting the 66i several times. Each time everything was there. Checked a route I was familiar with and all the info was there.

Problem solved.

I still do not understand why the 66i did not recognize the GPX files that were on the card when it was updated. Neither did Garmin support. But it seems loading them to the SD card from backup, through the 66i when it was connected to the computer did the trick.
Hope this will be useful to somebody else.
#56
Quote from: crislewis on September 08, 2022, 01:37:09 PMI just loaded a section of a map from CalTopo 2011 onto my GPSmap 78SC into internal memory, and disable all other maps. I set detail to MOST, but although I can see other features, the lakes are not displaying as blue bodies of water on the map. If I move the cursor to where the lake should be, it labels it, but it shows only as a blank on the topo, not a blue lake. I.e., it looks as if it is a meadow on the topo. None of the lakes in this map segment are showing up on my GPS display, at the highest zoom in level, although I can see them all in Basecamp on my PC. What is wrong?
Hi,
One possible reason for this issue is that the map you loaded does not have the correct data for the lakes. Another reason could be that the detail level is not set high enough to display the lakes as blue bodies of water on the map.

I suggest you try setting the detail level to HIGHEST and see if that helps. If you are still having issues after trying this, I recommend contacting Garmin support for further assistance.
#57
Using The Maps/Garmin Software / Re: Lost all routes after 66i ...
Last post by Boyd - June 23, 2023, 03:34:10 AM
Great - glad you got your data back!  8)
#58
Using The Maps/Garmin Software / Re: Lost all routes after 66i ...
Last post by TeleBruce - June 22, 2023, 11:37:31 AM
Well it took long enough.
got excellent support from Garmin to figure out what was going on here.
1) I needed a full system update, from 8.10 to 9.50  I used Mobile Garmin Express on my andriod. Took forever.

2) For reason still unknown, the 66i could 'see' my SD card, and could 'see' the .img files, but not the GPX files.

3) I connected my 66i to my computer and copied the GPX files from a backup into the internal GPX folder of the device. All is fine. I can access  them all.
Still not sure why I could not access them on the SD card. I can access the map, but not the GPX files.

One other option I have not tried yet (but will) is to reformat the sd card (FAT32), copy my backup files to it, and see if the 66i will recognize it as in the past. If it does I willremove the GPX files from internal memory and just use the SD card. Less of a chance of corrupting something in internal memory I would think.

IF YOU RUN LINUX
and you need to transfer files from a backup to your GPS, connect the device to your computer via USB data cable. it will be mounted as GARMIN. You can open it and get to any file folder on the device if necessary. copy the files you need to transfer and paste into the appropriate folder. Just be careful what you're doing of course!

thanks for  the help Boyd! Sometimes all I need is a nudge and I'll work whatever out.



#59
Using The Maps/Garmin Software / Re: Lost all routes after 66i ...
Last post by TeleBruce - June 21, 2023, 05:40:23 AM
Thanks Boyd. I'll try fooling with it this afternoon.
#60
Using The Maps/Garmin Software / Re: Lost all routes after 66i ...
Last post by Boyd - June 20, 2023, 05:49:00 PM
.img files are maps, not routes, so you don't want those. If you created routes, they should be somewhere in the GPX folder.

Yes, I think the 66i will automatically scan the card if you copy the folders to their original locations. Sorry, the 66 series is a new generation of Garmin device that I have not used.

Basecamp can be used to manage/transfer routes if you connect the GPS. However, apparently you are using Linux/unix and can't use Basecamp? It might be possible with Wine? If not Basecamp, I have read that Garmin's older software, Mapsource, can be used with Wine.