[Qgis-user] Aligning georeferenced USGS historical map

Mon Nov 19 05:32:04 PST 2018

It looks like the GeoTIFF at
https://ngmdb.usgs.gov/ht-bin/tv_download.pl?id=5504707&tif=true

actually uses an (almost) correct projection:

PROJCS["Polyconic",GEOGCS["GCS_North_American_1927",DATUM["D_North_American_1927",SPHEROID["Clarke_1866",6378206.4,294.9786982]],PRIMEM["Greenwi
ch",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Polyconic"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-122.625],PAR

AMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["Meter",1]]

and proj knows about polyconic:

https://proj4.org/operations/projections/poly.html

Since the geoTIFF projection mentions NAD 1927, perhaps the main issue the
datum shift mentioned on the map.

So I tried to find out about the datum actually used for the printed map
and found this:

https://historicalcharts.noaa.gov/links.html

linking to

https://historicalcharts.noaa.gov/pdfs/AR1853_Appendix39.pdf

Page 101 has a table of constant used for the polyconic projection
including the ellipsoid parameters (older than Clarke 1866).

With that a new custom projection can be defined:

+proj=poly +lat_0=0 +lon_0=-122.625 +x_0=0 +y_0=0 +a=6377397.16
+b=6356078.96 +units=m +no_defs

and assigned to the geoTIFF (without warping), replacing the NAD27 datum
definition.

Interestingly, this change shifts the map ca. 690ft north, and makes it
align better but not perfectly with modern maps. The purple tinted map
below is using the new custom projection, using on the on the fly
reprojection which may not be accurate enough.

 image.png
<https://drive.google.com/file/d/0BwIhFzkLaQ9Xd1pPd1FNTHM5WWplQTZVcHJ0S2pOUFFPM3Fz/view?usp=drive_web>

I think the dotted lines at the northern margin may correspond to the
location of the minute grid in the then new NAD 1927 datum. For the actual
corners, I think, another ellipsoid was used, probably the one above.

In the end, it may be necessary to just guess the true location of
landmarks on the map such as road intersections or bends, or the coastline,
and regeoreference using spline warping.

-Andreas

On Fri, Nov 16, 2018 at 8:36 AM Andreas Plesch <andreasplesch at netscape.net>
wrote:

> Looking at
>
>
> https://ngmdb.usgs.gov/img4/ht_icons/Browse/CA/CA_Tamalpais_301790_1897_62500.jpg
>
> there is a note in the lower right corner:
>
> Polyconic projection. To place on North American datum, move projection
> lines 690 ft south and 320 ft west.
>
> https://en.m.wikipedia.org/wiki/American_polyconic_projection
>
> explains the projection.
>
> Unfortunately, the map does not mention which central meridian was chosen
> for the projection. It may be possible to find if at the time a single one
> was used for all of CA and what it would be.
>
> It should also be straightforward to determine if proj  and therefore qgis
> supports the polyconic projection. It probably does.
>
> With that you can define a custom projection. Perhaps there is an EPSG
> code but I could not find it.
>
> EPSG 9818 seems to encode this projection although it does not seem to
> include the actual method in the registration.
>
> After you have defined a closely matching projection, you can translate
> the minute grid points to projected coordinates and georeference.
>
> The other mystery is the note about the datum shift. What are projection
> lines and what datum is used for the printed map ? The mentioned North
> American datum may be NAD27.
>
> Andreas
>
>
> From: Morgan Fletcher <morgan at hahaha.org>
>
>> To: qgis-user at lists.osgeo.org
>> Subject: [Qgis-user] Aligning georeferenced USGS historical maps
>> Message-ID:
>>         <
>> CAPwdt1U+TmE7cJR4GF63E13MPaPYWO9nsbzocHj2R8nG80duhw at mail.gmail.com>
>> Content-Type: text/plain; charset="utf-8"
>>
>> I am new to GIS, an amateur who is curious about old roads. I have QGIS
>> 3.4.0 installed on OS-X 10.13.6 using the pre-built binaries available
>> from
>> https://download.qgis.org/. If I visit the USGS topoView
>> <https://ngmdb.usgs.gov/topoview/> page and download a historic map, for
>> instance the geotiff archive from Tamalpais, CA 1897 (1950 ed.)
>> <https://ngmdb.usgs.gov/topoview/viewer/#10/37.8564/-122.6336>, I can
>> add a
>> raster layer with the .tif file from the archive and it will be placed in
>> rough correspondence with a base map in my QGIS project. In my case my
>> basemap is OpenStreetMap. (crs=EPSG:3857&format&type=xyz&url=
>> http://a.tile.openstreetmap.org/%7Bz%7D/%7Bx%7D/%7By%7D.png&zmax=19&zmin=0
>> )
>> The problem is that the maps don't line up, visually. For example:
>>
>>
>>  Screen Shot 2018-11-02 at 8.51.02 AM.png
>> <
>> https://drive.google.com/a/hahaha.org/file/d/0B-OybZpGWIkHUWhuWEZLS2xWZEhTUC1MMkN4X2dfZGkxQm1J/view?usp=drive_web
>> >
>>
>>
>> I can solve it better with georeferencer. Before I viewed Hans van der
>> Kwast's excellent Georeferencing a scanned map and digitizing vectors in
>> QGIS <https://youtu.be/4IWyVeGhzog> video, I simply started finding
>> common
>> points; now I understand that using the correct CRS, projection and the
>> grid is perhaps perhaps the best strategy.
>>
>> My questions are:
>>
>>
>>    - If I download a geotiff archive from topoView, is QGIS 3.4.0
>> correctly
>>    parsing the data in the .tif file, or the other files (.prj, .tfw) in
>> the
>>    extracted directory, and placing the map correctly? Can it be adjusted
>> to
>>    align better, and if so, how?
>>    - Should I use EPSG:26710 for the Tamalpais
>>    <https://ngmdb.usgs.gov/topoview/viewer/#10/37.8754/-122.6260> map,
>> and
>>    attempt to georeference it myself, using its minute grid? Why does the
>> map
>>    border show a skew at the top left and right corners? (see below)
>>    - I have found that, to get a hand-drawn, antique map to align with a
>>    modern base map, I often have to add so many points in georeferencer
>> that
>>    the rendered map has to be very distorted. What is the best method to
>> get
>>    old maps to line up, so that historical roads can be related to modern
>>    roads?
>>
>> Skew mentioned in second point:
>>
>>
>>  Screen Shot 2018-11-08 at 8.20.56 AM.png
>> <
>> https://drive.google.com/a/hahaha.org/file/d/0B-OybZpGWIkHeEE0aDMyQVFCZ0F1R01pRGhKeEJVTzYxaEpj/view?usp=drive_web
>> >
>>
>>
>> I couldn't find a searchable archive of qgis-user; my apologies if these
>> are already answered somewhere. I did ask a variation of these questions
>> on
>> StackExchange
>> <
>> https://gis.stackexchange.com/questions/301199/fix-offset-of-geotiff-file
>> >,
>> where it was heavily edited by 'Vince', and has no answers after a week,
>> so
>> asking here.
>>
>> Morgan
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>

-- 
Andreas Plesch
Waltham, MA 02453
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