Re: [GRASS-user] Polar projection

2021-01-02 Thread Jón Eiríksson 

Dear Ken,

I am afraid I do have the same problem, - the command does not make a 
grid to the pole. Should have tested before responding, sorry. So I 
think you should proceed with a bug report,


Jon



On 1 Jan 2021, at 17:12, Ken Mankoff wrote:


Hi Jón,

I work regularly in EPSG:3413, but the same issue applies. "d.grid -g 
1:0" doesn't make a grid to the pole. Does it for you? I'd like to 
submit a bug report as per the suggestion from Markus, but am not sure 
what the bug is if this command works for you when the pole is 
included in the view.


  -k.

On 2020-12-31 at 09:23 -08, Jón Eiríksson  wrote...

This has worked for me:

(Thu Dec 31 17:22:11 2020)
g.proj -p
-PROJ_INFO-
name   : Stereographic
proj   : stere
datum  : wgs84
ellps  : wgs84
lat_0  : 90
lat_ts : 70
lon_0  : -45
k  : 1
x_0: 0
y_0: 0
no_defs: defined
towgs84: 0.000,0.000,0.000
-PROJ_EPSG-
epsg   : 3413
-PROJ_UNITS
unit   : meter
units  : meters
meters : 1
(Thu Dec 31 17:22:11 2020) Command finished (0 sec)

Jon




On 31 Dec 2020, at 16:26, Markus Neteler wrote:


Hi Ken,

On Thu, Dec 31, 2020 at 3:06 AM Ken Mankoff  
wrote:


Dear GRASS List,

Can someone suggest what setup to use (EPSG code? proj4 code?) to
have the projection centered on the N. pole? I'm looking to create
a graphic similar to this image in the Raster Gallery:
https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgrass.osgeo.org%2F%2Fimages%2Fgallery%2Fraster%2Fday_on_earth_N.pngdata=04%7C01%7Cjeir%40hi.is%7Cbab065ba5fa94867219a08d8ae786727%7C09fa5f0e211846568529677ed8fdbe78%7C0%7C0%7C637451179441104707%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=zcVbgCptTcrREvuVucAfEWdb%2BPH2Qsl6DktIkru94jE%3Dreserved=0

If I set up a polar projection based on
https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fspatialreference.org%2Fref%2Fsr-org%2F8243%2Fdata=04%7C01%7Cjeir%40hi.is%7Cbab065ba5fa94867219a08d8ae786727%7C09fa5f0e211846568529677ed8fdbe78%7C0%7C0%7C637451179441104707%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=QrsQH1MA6ehd%2BcPpLwwQ6190ki6shHnr7UptJsF50EU%3Dreserved=0
using:

grass -c ./G
g.proj -c proj4="+proj=stere +lat_0=90 +lat_ts=45 +lon_0=-170 +k=1
+x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs"

Things mostly work, but

d.grid -g 1:0 color=red

does not show latitude lines on most of the graphic (see attached).


I managed to generate it with

Preparation of a 10 degree grid:

# EPSG:4326
GRASS :~ > g.region -dp
projection: 3 (Latitude-Longitude)
zone:   0
datum:  wgs84
ellipsoid:  wgs84
north:  90N
south:  90S
west:   180W
east:   180E
nsres:  1
ewres:  1
rows:   180
cols:   360
cells:  64800
GRASS :~ > v.mkgrid grid=36,18 map=grid_10deg
# download "Natural Earth I with Shaded Relief, Water, and 
Drainages"

from
https://eur02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.naturalearthdata.com%2Fdownloads%2F10m-raster-data%2F10m-natural-earth-1%2Fdata=04%7C01%7Cjeir%40hi.is%7Cbab065ba5fa94867219a08d8ae786727%7C09fa5f0e211846568529677ed8fdbe78%7C0%7C0%7C637451179441104707%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=BmlSMFy8mUpdUQxbZw10dM7Rzzq4Vztpc33Ha8dx75M%3Dreserved=0
GRASS :~ > r.import in=NE1_HR_LC_SR_W_DR.tif
output=natural_earth_global_landcover
GRASS :~ > g.region raster=natural_earth_global_landcover.1
GRASS :~ > r.composite r=natural_earth_global_landcover.1
g=natural_earth_global_landcover.2 
b=natural_earth_global_landcover.3

out=natural_earth_global_landcover.rgb
GRASS :~ > exit

# WGS 84 / Arctic Polar Stereographic
https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fepsg.io%2F3995data=04%7C01%7Cjeir%40hi.is%7Cbab065ba5fa94867219a08d8ae786727%7C09fa5f0e211846568529677ed8fdbe78%7C0%7C0%7C637451179441104707%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=67g63WlKT3zJfzmTuPxNAciU9Uq65N%2F6ypc%2FpjntWT8%3Dreserved=0
grass78 -c epsg:3995 ~/grassdata/arctic_polar_stereographic
GRASS :~ > g.proj -w
PROJCS["WGS 84 / Arctic Polar Stereographic",
GEOGCS["WGS 84",
DATUM["WGS_1984",
SPHEROID["WGS 84",6378137,298.257223563,
AUTHORITY["EPSG","7030"]],
AUTHORITY["EPSG","6326"]],
PRIMEM["Greenwich",0,
AUTHORITY["EPSG","8901"]],
UNIT["degree",0.0174532925199433,
AUTHORITY["EPSG","9122"]],
AUTHORITY["EPSG","4326"]],
PROJECTION["Polar_Stereographic"],
PARAMETER["latitude_of_origin",71],
PARAMETER["central_meridian",0],
PARAMETER["false_easting",0],
PARAMETER["false_northing",0],
UNIT["metre",1,

Re: [GRASS-user] Polar projection

2021-01-01 Thread Ken Mankoff 
Hi Markus,

On 2020-12-31 at 08:26 -08, Markus Neteler  wrote...
> On Thu, Dec 31, 2020 at 3:06 AM Ken Mankoff  wrote:
>> d.grid -g 1:0 color=red
>>
>> does not show latitude lines on most of the graphic (see attached).
>
> I managed to generate it with
>
> Preparation of a 10 degree grid [in EPSG:4326]:
> v.mkgrid grid=36,18 map=grid_10deg
>
> [v.proj from 4326 to polar (3995 or 3413)]
>
> The resulting map looks as attached (hope I didn't forget to copy a
> command here). Indeed, d.grid doesn't looks as expected

Your command list was helpful. Yes, things work fine when importing a grid 
generated in EPSG:4326 to EPSG:3995. Oddly, importing to EPSG:3413 has a 
different issue (included in the same bug report for now).

> d.grid 10 -w .. is incomplete. Worth a bug report, IMO.

https://github.com/OSGeo/grass/issues/1224

Thanks,

  -k.
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Re: [GRASS-user] Polar projection

2021-01-01 Thread Ken Mankoff 
Hi Jón,

I work regularly in EPSG:3413, but the same issue applies. "d.grid -g 1:0" 
doesn't make a grid to the pole. Does it for you? I'd like to submit a bug 
report as per the suggestion from Markus, but am not sure what the bug is if 
this command works for you when the pole is included in the view.

  -k.

On 2020-12-31 at 09:23 -08, Jón Eiríksson  wrote...
> This has worked for me:
>
> (Thu Dec 31 17:22:11 2020)
> g.proj -p
> -PROJ_INFO-
> name   : Stereographic
> proj   : stere
> datum  : wgs84
> ellps  : wgs84
> lat_0  : 90
> lat_ts : 70
> lon_0  : -45
> k  : 1
> x_0: 0
> y_0: 0
> no_defs: defined
> towgs84: 0.000,0.000,0.000
> -PROJ_EPSG-
> epsg   : 3413
> -PROJ_UNITS
> unit   : meter
> units  : meters
> meters : 1
> (Thu Dec 31 17:22:11 2020) Command finished (0 sec)
>
> Jon
>
>
>
>
> On 31 Dec 2020, at 16:26, Markus Neteler wrote:
>
>> Hi Ken,
>>
>> On Thu, Dec 31, 2020 at 3:06 AM Ken Mankoff  wrote:
>>>
>>> Dear GRASS List,
>>>
>>> Can someone suggest what setup to use (EPSG code? proj4 code?) to
>>> have the projection centered on the N. pole? I'm looking to create
>>> a graphic similar to this image in the Raster Gallery: 
>>> https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgrass.osgeo.org%2F%2Fimages%2Fgallery%2Fraster%2Fday_on_earth_N.pngdata=04%7C01%7Cjeir%40hi.is%7Cc4ce599d0faf40d3408608d8ada8dff2%7C09fa5f0e211846568529677ed8fdbe78%7C0%7C0%7C637450288118244590%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=1b0EG%2B%2ByT0LjNGOp55l%2FwYiVKSNfAeUvd%2BZS12dCWZg%3Dreserved=0
>>>
>>> If I set up a polar projection based on
>>> https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fspatialreference.org%2Fref%2Fsr-org%2F8243%2Fdata=04%7C01%7Cjeir%40hi.is%7Cc4ce599d0faf40d3408608d8ada8dff2%7C09fa5f0e211846568529677ed8fdbe78%7C0%7C0%7C637450288118244590%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=I7u9KAIJ0geqmtTPZv1vUg3kiAtqtASajvhxzCwFmy4%3Dreserved=0
>>>  
>>> using:
>>>
>>> grass -c ./G
>>> g.proj -c proj4="+proj=stere +lat_0=90 +lat_ts=45 +lon_0=-170 +k=1
>>> +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs"
>>>
>>> Things mostly work, but
>>>
>>> d.grid -g 1:0 color=red
>>>
>>> does not show latitude lines on most of the graphic (see attached).
>>
>> I managed to generate it with
>>
>> Preparation of a 10 degree grid:
>>
>> # EPSG:4326
>> GRASS :~ > g.region -dp
>> projection: 3 (Latitude-Longitude)
>> zone:   0
>> datum:  wgs84
>> ellipsoid:  wgs84
>> north:  90N
>> south:  90S
>> west:   180W
>> east:   180E
>> nsres:  1
>> ewres:  1
>> rows:   180
>> cols:   360
>> cells:  64800
>> GRASS :~ > v.mkgrid grid=36,18 map=grid_10deg
>> # download "Natural Earth I with Shaded Relief, Water, and Drainages"
>> from
>> https://eur02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.naturalearthdata.com%2Fdownloads%2F10m-raster-data%2F10m-natural-earth-1%2Fdata=04%7C01%7Cjeir%40hi.is%7Cc4ce599d0faf40d3408608d8ada8dff2%7C09fa5f0e211846568529677ed8fdbe78%7C0%7C0%7C637450288118244590%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=at%2BPzc3vGV%2FmxVhg%2BxltDODIC52rrl%2Bd39ZTtta7uDA%3Dreserved=0
>> GRASS :~ > r.import in=NE1_HR_LC_SR_W_DR.tif
>> output=natural_earth_global_landcover
>> GRASS :~ > g.region raster=natural_earth_global_landcover.1
>> GRASS :~ > r.composite r=natural_earth_global_landcover.1
>> g=natural_earth_global_landcover.2 b=natural_earth_global_landcover.3
>> out=natural_earth_global_landcover.rgb
>> GRASS :~ > exit
>>
>> # WGS 84 / Arctic Polar Stereographic
>> https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fepsg.io%2F3995data=04%7C01%7Cjeir%40hi.is%7Cc4ce599d0faf40d3408608d8ada8dff2%7C09fa5f0e211846568529677ed8fdbe78%7C0%7C0%7C637450288118244590%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=JwnkjczUnnrbi%2F%2BnQGepiYo4eB02S5%2BQUWSMK3rRFDs%3Dreserved=0
>> grass78 -c epsg:3995 ~/grassdata/arctic_polar_stereographic
>> GRASS :~ > g.proj -w
>> PROJCS["WGS 84 / Arctic Polar Stereographic",
>> GEOGCS["WGS 84",
>> DATUM["WGS_1984",
>> SPHEROID["WGS 84",6378137,298.257223563,
>> AUTHORITY["EPSG","7030"]],
>> AUTHORITY["EPSG","6326"]],
>> PRIMEM["Greenwich",0,
>> AUTHORITY["EPSG","8901"]],
>> UNIT["degree",0.0174532925199433,
>> AUTHORITY["EPSG","9122"]],
>> AUTHORITY["EPSG","4326"]],
>> PROJECTION["Polar_Stereographic"],
>> PARAMETER["latitude_of_origin",71],
>> PARAMETER["central_meridian",0],
>> PARAMETER["false_easting",0],
>>

Re: [GRASS-user] Polar projection

2020-12-31 Thread Jón Eiríksson 

This has worked for me:

(Thu Dec 31 17:22:11 2020)
g.proj -p
-PROJ_INFO-
name   : Stereographic
proj   : stere
datum  : wgs84
ellps  : wgs84
lat_0  : 90
lat_ts : 70
lon_0  : -45
k  : 1
x_0: 0
y_0: 0
no_defs: defined
towgs84: 0.000,0.000,0.000
-PROJ_EPSG-
epsg   : 3413
-PROJ_UNITS
unit   : meter
units  : meters
meters : 1
(Thu Dec 31 17:22:11 2020) Command finished (0 sec)

Jon




On 31 Dec 2020, at 16:26, Markus Neteler wrote:


Hi Ken,

On Thu, Dec 31, 2020 at 3:06 AM Ken Mankoff  wrote:


Dear GRASS List,

Can someone suggest what setup to use (EPSG code? proj4 code?) to 
have the projection centered on the N. pole? I'm looking to create a 
graphic similar to this image in the Raster Gallery: 
https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgrass.osgeo.org%2F%2Fimages%2Fgallery%2Fraster%2Fday_on_earth_N.pngdata=04%7C01%7Cjeir%40hi.is%7Cc4ce599d0faf40d3408608d8ada8dff2%7C09fa5f0e211846568529677ed8fdbe78%7C0%7C0%7C637450288118244590%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=1b0EG%2B%2ByT0LjNGOp55l%2FwYiVKSNfAeUvd%2BZS12dCWZg%3Dreserved=0


If I set up a polar projection based on 
https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fspatialreference.org%2Fref%2Fsr-org%2F8243%2Fdata=04%7C01%7Cjeir%40hi.is%7Cc4ce599d0faf40d3408608d8ada8dff2%7C09fa5f0e211846568529677ed8fdbe78%7C0%7C0%7C637450288118244590%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=I7u9KAIJ0geqmtTPZv1vUg3kiAtqtASajvhxzCwFmy4%3Dreserved=0 
using:


grass -c ./G
g.proj -c proj4="+proj=stere +lat_0=90 +lat_ts=45 +lon_0=-170 +k=1 
+x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs"


Things mostly work, but

d.grid -g 1:0 color=red

does not show latitude lines on most of the graphic (see attached).


I managed to generate it with

Preparation of a 10 degree grid:

# EPSG:4326
GRASS :~ > g.region -dp
projection: 3 (Latitude-Longitude)
zone:   0
datum:  wgs84
ellipsoid:  wgs84
north:  90N
south:  90S
west:   180W
east:   180E
nsres:  1
ewres:  1
rows:   180
cols:   360
cells:  64800
GRASS :~ > v.mkgrid grid=36,18 map=grid_10deg
# download "Natural Earth I with Shaded Relief, Water, and Drainages"
from 
https://eur02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.naturalearthdata.com%2Fdownloads%2F10m-raster-data%2F10m-natural-earth-1%2Fdata=04%7C01%7Cjeir%40hi.is%7Cc4ce599d0faf40d3408608d8ada8dff2%7C09fa5f0e211846568529677ed8fdbe78%7C0%7C0%7C637450288118244590%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=at%2BPzc3vGV%2FmxVhg%2BxltDODIC52rrl%2Bd39ZTtta7uDA%3Dreserved=0

GRASS :~ > r.import in=NE1_HR_LC_SR_W_DR.tif
output=natural_earth_global_landcover
GRASS :~ > g.region raster=natural_earth_global_landcover.1
GRASS :~ > r.composite r=natural_earth_global_landcover.1
g=natural_earth_global_landcover.2 b=natural_earth_global_landcover.3
out=natural_earth_global_landcover.rgb
GRASS :~ > exit

# WGS 84 / Arctic Polar Stereographic 
https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fepsg.io%2F3995data=04%7C01%7Cjeir%40hi.is%7Cc4ce599d0faf40d3408608d8ada8dff2%7C09fa5f0e211846568529677ed8fdbe78%7C0%7C0%7C637450288118244590%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=JwnkjczUnnrbi%2F%2BnQGepiYo4eB02S5%2BQUWSMK3rRFDs%3Dreserved=0

grass78 -c epsg:3995 ~/grassdata/arctic_polar_stereographic
GRASS :~ > g.proj -w
PROJCS["WGS 84 / Arctic Polar Stereographic",
GEOGCS["WGS 84",
DATUM["WGS_1984",
SPHEROID["WGS 84",6378137,298.257223563,
AUTHORITY["EPSG","7030"]],
AUTHORITY["EPSG","6326"]],
PRIMEM["Greenwich",0,
AUTHORITY["EPSG","8901"]],
UNIT["degree",0.0174532925199433,
AUTHORITY["EPSG","9122"]],
AUTHORITY["EPSG","4326"]],
PROJECTION["Polar_Stereographic"],
PARAMETER["latitude_of_origin",71],
PARAMETER["central_meridian",0],
PARAMETER["false_easting",0],
PARAMETER["false_northing",0],
UNIT["metre",1,
AUTHORITY["EPSG","9001"]],
AXIS["Easting",SOUTH],
AXIS["Northing",SOUTH],
AUTHORITY["EPSG","3995"]]

GRASS :~ > g.region n=293 s=-250 w=-425 e=431
nsres=1 ewres=1 -p
GRASS :~ > v.proj location=latlong_wgs84 mapset=PERMANENT 
input=grid_10deg

GRASS :~ > r.proj location=latlong_wgs84 mapset=PERMANENT
input=natural_earth_global_landcover.rgb
GRASS :~ > d.mon wx0
GRASS :~ > d.rast natural_earth_global_landcover.rgb
GRASS :~ > d.vect grid_10deg type=boundary

The resulting map looks as attached (hope I didn't forget to copy a
command here).
Indeed,

Re: [GRASS-user] polar projection with grid lines

2017-05-29 Thread Moritz Lennert 
Le Sun, 28 May 2017 08:29:48 -0400,
Ken Mankoff  a écrit :

> Hi List,
> 
> I'm trying to set up a polar projection and draw some grid lines. I'm
> having trouble a) getting the grid lines to the pole and b) rotating
> it so a different longitude is the center longitude. I'm using the
> following code:
> 
> grass72 -e -c epsg:3413 ./tmp
> grass72 ./tmp/PERMANENT
> 
> xy0=$(m.proj -i coordinates=0,40)  # set corners to 40° N
> xy1=$(m.proj -i coordinates=180,40)
> x0=$(echo ${xy0} | cut -d"|" -f1)
> y0=$(echo ${xy0} | cut -d"|" -f2)
> x1=$(echo ${xy1} | cut -d"|" -f1)
> y1=$(echo ${xy1} | cut -d"|" -f2)
> 
> g.region s=${y0} n=${y1} w=${x1} e=${x0}
> 
> d.mon start=wx0
> d.erase
> d.grid -w size=10:0
> 
> 
> The d.grid manual suggests calling 2x near the poles, but even doing
> that (e.g. d.grid -w size=1 direction=east-west) does not improve
> where the grid lines are drawn. Also, if I wanted Russia, not
> Greenland, pointing "down" on the map, how do I rotate this
> projection?
> 


Can't help you with you grid problems right now, but for "rotating"
your projection, you would have to create a new location with modified
projection parameters. Just change the lon_0 value to whatever meridian
you want as central:

Original EPSG 3413 :
+proj=stere +lat_0=90 +lat_ts=70 +lon_0=-45 +k=1 +x_0=0 +y_0=0
+datum=WGS84 +units=m +no_defs  <>


Centered on Novosibirsk:

+proj=stere +lat_0=90 +lat_ts=70 +lon_0=83 +k=1 +x_0=0
+y_0=0 +datum=WGS84 +units=m +no_defs  <>

You can then create the new location using the "custom PROJ.4
parameters" option for defining the projection and pasting the above
definition.

Moritz
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