Ramon,
The text file is closer to your Example B, but the survey system
itself has discontinuities such as how it tries to deal with Longitude
convergence and keep the parcel sizes roughly the same. A good summary
of the system can be found at:
http://www.thinktrees.org/my_folders/Envirothon_Soils_Resources_2010/7_-_Understanding_Western_Canada_Dominion_Land_Survey_System.pdf
(although I see they didn't scan the pages relating to Alberta)
Before the responsibility for the system was given to the Provinces, the
Federal govt called it the "Dominion Land Survey System", so if you
Google that you will get more info. The authoritative document was the
"Manual of Instructions for the Survey of Dominion Lands", available
from:
http://clss.nrcan.gc.ca/standards-normes/toc-domlan-terredom-1-3-v1-eng.php
Here's a few records from the ATS_V4_1.SEQ text file:
40100101E449.00701238110.0050793319840621S07LBD 1421
0.000000000 199104030000000020050331113922
40100101N449.01415809110.0161551119840621S07LBD 1421 0.000000000
199104030000000020050331113922
40100101NE49.01424023110.0050807519840621S07LBD 1421
855.6194501019111199104030000000020050331113922
40100101P148.99961020110.0008710619360101S06394 IBC 3125
856.5193601012511199104030000000020050331113922
40100101P248.99960948110.0050779020041123S07A477 SE COR 1525
0.000000000 000000000000000020050331113922
40100101S448.99978158110.0161736619910314S08TIED IBC 3943125
0.000000000 199104030000000020050331113922
40100101SE48.99978996110.0050779420000614S06LBD 9/306 1125
856.519901220C721199104030000000020050331113922
40100102E449.00683419110.0275199620000614S07LBD 1421 0.000000000
199104030000000020050331113922
and my INSERT statement to load the points into a PostGIS table:
INSERT INTO ats_coords(
meridian,
range,
township,
section,
qsection,
lat,
lon,
date_computed,
station,
status,
horizontal_class,
"comment",
horizontal_origin,
horizontal_method,
horizontal_datum,
road,
elevation,
elevation_date,
elevation_origin,
elevation_method,
elevation_accuracy,
vertical_datum,
parcel_computed,
map_computed,
date_updated
)
SELECT
substr(rec,1,1) AS meridian,
substr(rec,2,2) AS range,
substr(rec,4,3) AS township,
substr(rec,7,2) AS section,
substr(rec,9,2) AS qsection,
CAST(substr(rec,11,11) AS double precision) AS lat,
CAST(substr(rec,22,12) AS double precision) AS lon,
substr(rec,34,8) AS date_computed,
substr(rec,42,1) AS station,
substr(rec,43,1) AS status,
substr(rec,44,1) AS horizontal_class,
substr(rec,45,12) AS "comment",
substr(rec,57,1) AS horizontal_origin,
substr(rec,58,1) AS horizontal_method,
substr(rec,59,1) AS horizontal_datum,
substr(rec,60,1) AS road,
CAST(substr(rec,61,6) AS double precision) AS elevation,
substr(rec,67,8) AS elevation_date,
substr(rec,75,1) AS elevation_origin,
substr(rec,76,1) AS elevation_method,
substr(rec,77,1) AS elevation_accuracy,
substr(rec,78,1) AS vertical_datum,
substr(rec,79,8) AS parcel_computed,
substr(rec,87,8) AS map_computed,
to_timestamp(substr(rec,95,14),'YYYYMMDDHHMISS') AS date_updated
FROM ats_raw;
Best Regards,
Brent Fraser
On 5/20/2014 3:39 PM, Ramon Andiñach wrote:
On 20/05/2014, at 22:42 , Brent Fraser wrote:
Michael,
The Alberta Township System can be a pain to relate to geographic coordinates. While
it is a survey system (or land parcel definition system) defined by physical monuments
placed on the ground, it is often just "estimated" using the original rules
used in laying out the monuments back in the late 1800s.
The official source of the data is
http://www.altalis.com/products/property/ats.html. While the polygon file is
provided at a cost ($1000), a text file of survey corners is available for
free. But joining the corners into polygons is not for the faint of heart.
Brent and Michael,
Out of curiosity (because I'm about as far away as Phil is and have no idea
what an ATS polygon file should look like) do either of you know what that text
file looks like?
I suppose my question is are the points for each node on a quarter shown
separately (like example A)?
or is it more messy where unique nodes are recorded, but shared between
polygons (like example B)?
or something else?
If it's the first one, I've probably got something at work that could do most
of the heavy lifting on it for you.
If it's one of the others then it would be more involved.
-ramon.
Example A
_________
| 2 | 1 |
|___|___|
x y z quarter1
x y z quarter1
x y z quarter1
x y z quarter1
x y z quarter2
x y z quarter2
x y z quarter2
x y z quarter2
Example B
_____________
| 2 | 3 | 4 |
|___|___|___|
| 9 | 1 | 5 |
|___|___|___|
| 8 | 7 | 6 |
|___|___|___|
x y z quarter1, quarter2. quarter3, quarter9
x y z quarter1, quarter3, quarter4, quarter5
x y z quarter1, quarter5, quarter6, quarter7
x y z quarter1, quarter7, quarter8, quarter9
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