[GRASSLIST:5706] v.proj problems - state plane to UTM
Philipp Molzer
phil at molzer.net
Sun Mar 2 12:13:23 EST 2003
Hi,
I'm using grass5.0.0 on Linux RedHat8 (intel).
I have a DEM upon which I'd like to overlay some census data (vectors).
The DEM is in UTM format while the vectors are in state plane format.
Both locations are NAD83. Both cover the area of Essex County, New
Jersey, USA. When I use v.proj to bring the vectors from my state plane
location to my UTM location, the resulting vector data has coordinates
that seem to be incompatible with the DEM coordinates. The east and
west bounds of the imported vector layer appear to be way off.
Also, I can't figure out how to change locations except by exiting and
restarting grass.
Here are the details:
Source of DEM
DEM was imported into a location with these specifications
name: UTM
datum: nad83
dx: 0.000000
dy: 0.000000
dz: 0.000000
proj: utm
ellps: grs80
a: 6378137.0000000000
es: 0.0066943800
f: 298.2572221010
zone: 18
-----------------------------------------------------------
PROJ_UNITS file:
unit: meter
units: meters
meters: 1.0
This is the code I used to do the import.
#the DEM is a set of patched together DEMs which I got from the New
Jersey geol survey, covering Essex county
#the DEMs were in SDTS format
#this script includes extracting the files and importing them, then
patching all together
cd /DATA/GIS/NJ/ESSEX/DEM
export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:/usr/local/lib:/usr/lib
LIST=`ls -1 *.GZ`
L1=`echo $LIST |sed -e "s/\.DEM\.SDTS\.TAR\.GZ//g"`
for FILE in $L1; do
mkdir $FILE
mv ${FILE}* $FILE
cd $FILE
tar zxvf ${FILE}.DEM.SDTS.TAR.GZ
FILE=`ls *CATD*`
F1=`echo $FILE |awk '{print substr($0,0,4)}'`
OUT=`echo $DIR |sed -e "s/\///"`
r.in.gdal -e input=$FILE output=$OUT
r.support -r map=$OUT
cd ..
done
r.patch
input=1705847,1705869,1706050,1706056,1706084,1706086,1706096,1706105
output=essexdem
r.info map=essexdem
+----------------------------------------------------------------------------+
| Layer: essexdem Date: Sun Feb 23
14:47:27 2003 |
| Mapset: essex_utm Login of Creator:
pmolzer |
| Location:
NJ_utm |
| DataBase:
/home/pmolzer/grassdata |
| Title: ( essexdem
) |
|----------------------------------------------------------------------------|
|
|
| Type of Map: raster Number of Categories:
80 |
| Data Type:
FCELL |
| Rows:
25848 |
| Columns:
22425 |
| Total Cells:
579641400 |
| Projection: UTM (zone
18) |
| N: 4528864.484212 S: 4503016.5481 Res:
0.99999753 |
| E: 574950.240953 W: 552525.236985 Res:
1.00000018 |
| Range of data: min = 0.000000 max =
206.899994 |
|
|
| Data
Source:
|
|
|
|
|
|
|
| Data
Description:
|
| generated by r.patch
Source of vectors
Vectors were imported into a location with these specifications:
name: State Plane
datum: nad83
dx: 0.000000
dy: 0.000000
dz: 0.000000
proj: tmerc
a: 0.63782064e+07
es: 0.6768657997291094e-02
x_0: 0.6096012192024384e+06
y_0: 0
k: 0.999975e+00
lon_0: 74d40'w
lat_0: 38d50'n
-----------------------------------------------------------
PROJ_UNITS file:
unit: foot
units: feet
meters: 0.3048000000
Source data was an arc/info vector .shp file downloaded from New Jersey DEP
http://www.state.nj.us/dep/gis/digidownload/zips/trct/esstrct.zip
This is the script I used to do the import:
BASE=/DATA/GIS/NJ/ESSEX
SHP=esstrct
g.region rast=essexdem
cd ${BASE}/$SHP
for ATT in AREA PERIMETER SUM_TOTALP ; do
v.in.shape -o in=${SHP}.shp out=${SHP}_$ATT attribute=$ATT scale=24000
v.support map=${SHP}_$ATT option=build
done
v.info esstrct_AREA
+----------------------------------------------------------------------------+
| Layer: esstrct_AREA Date: Sun Feb 16
22:44:45 |
| Mapset: state1
Organization: |
| Location: NJ_stpln Name of
creator: |
| DataBase:
/home/pmolzer/grassdata |
| Title: Vector map: esstrct_AREA (
esstrct_AREA) |
|----------------------------------------------------------------------------|
|
|
| Type of Map: Vector (level: 2) Number of Categories:
1 |
| Number of lines:
644 |
| Number of areas:
226 |
| Number of islands:
2 |
|
|
| Projection: State Plane (zone
0) |
| N: 756057 S:
670935 |
| E: 599476 W:
526003 |
|
|
| Source
date: |
| Original scale
1:24000 |
| Map threshold: 0.00000
I then bring the vectors into my UTM project like this
v.proj input=esstrct_AREA location=NJ_stpln mapset=state1
output=esstrct_AREA
v.support esstrct_AREA
which gives me:
v.info esstrct_AREA
+----------------------------------------------------------------------------+
| Layer: esstrct_AREA Date: Mar 2
3 |
| Mapset: essex_utm
Organization: |
| Location: NJ_utm Name of creator:
esstrct_AREA |
| DataBase:
/home/pmolzer/grassdata |
| Title: Vector map: esstrct_AREA (
esstrct_AREA) |
|----------------------------------------------------------------------------|
|
|
| Type of Map: Vector (level: 2) Number of Categories:
1 |
| Number of lines:
644 |
| Number of areas:
226 |
| Number of islands:
2 |
|
|
| Projection: UTM (zone
18) |
| N: 4527072 S:
4501059 |
| E: 101524 W:
79046 |
|
|
| Source
date: |
| Original scale
1:24000 |
| Map threshold:
0.00000 |
|
Comments:
|
| /home/pmolzer/grassdata/NJ_utm/essex_utm/dig_cats
The East and West bounds are totally different than for the DEM, which were
N: 4528864.484212 S: 4503016.5481 Res: 0.99999753
E: 574950.240953 W: 552525.236985 Res: 1.00000018
Thanks,
Phil
More information about the grass-user
mailing list