Tribblix: manual page: projinfo.1

PROJINFO(1) PROJ PROJINFO(1)

NAME

projinfo - Geodetic object and coordinate operation queries

SYNOPSIS

projinfo
[-o formats] [-k crs|operation|datum|ensemble|ellipsoid] [--summary] [-q]
[[--area name_or_code] | [--bbox west_long,south_lat,east_long,north_lat]]
[--spatial-test contains|intersects]
[--crs-extent-use none|both|intersection|smallest]
[--grid-check none|discard_missing|sort|known_available]
[--pivot-crs always|if_no_direct_transformation|never|{auth:code[,auth:code]*}]
[--show-superseded] [--hide-ballpark] [--accuracy {accuracy}]
[--allow-ellipsoidal-height-as-vertical-crs]
[--boundcrs-to-wgs84]
[--authority name]
[--main-db-path path] [--aux-db-path path]*
[--dump-db-structure]
[--identify] [--3d]
[--output-id AUTH:CODE]
[--c-ify] [--single-line]
--searchpaths | --remote-data |
--list-crs [list-crs-filter] |
--dump-db-structure [{object_definition} | {object_reference}] |
{object_definition} | {object_reference} |
(-s {srs_def} [--s_epoch {epoch}] -t {srs_def} [--t_epoch {epoch}]) |
({srs_def} {srs_def})

where {object_definition} or {srs_def} is one of the possibilities
accepted by proj_create()

+o a proj-string,

+o a WKT string,

+o an object code (like "EPSG:4326", "urn:ogc:def:crs:EPSG::4326",
"urn:ogc:def:coordinateOperation:EPSG::1671"),

+o an Object name. e.g "WGS 84", "WGS 84 / UTM zone 31N". In that
case as uniqueness is not guaranteed, heuristics are applied to
determine the appropriate best match.

+o a CRS name and a coordinate epoch, separated with '@'. For
example "ITRF2014@2025.0". (added in 9.2)

+o a OGC URN combining references for compound coordinate reference
systems (e.g "urn:ogc:def:crs,crs:EPSG::2393,crs:EPSG::5717" or
custom abbreviated syntax "EPSG:2393+5717"),

+o a OGC URN combining references for references for projected or
derived CRSs e.g. for Projected 3D CRS "UTM zone 31N / WGS 84
(3D)":
"urn:ogc:def:crs,crs:EPSG::4979,cs:PROJ::ENh,coordinateOperation:EPSG::16031"
(added in 6.2)

+o Extension of OGC URN for CoordinateMetadata. e.g.
"urn:ogc:def:CoordinateMetadata:NRCAN::NAD83_CSRS_1997_MTM11_HT2_1997"

+o a OGC URN combining references for concatenated operations (e.g.
"urn:ogc:def:coordinateOperation,coordinateOperation:EPSG::3895,coordinateOperation:EPSG::1618")

+o a PROJJSON string. The jsonschema is at
https://proj.org/schemas/v0.4/projjson.schema.json (added in
6.2)

+o a compound CRS made from two object names separated with " + ".
e.g. "WGS 84 + EGM96 height" (added in 7.1)

{object_reference} is a filename preceded by the '@' character.
The file referenced by the {object_reference} must contain a valid
{object_definition}.

The usage of "{srs_def} {srs_def}" is equivalent to "-s {srs_def}
-t {srs_def}" (added in 9.5).

DESCRIPTION

projinfo is a program that can query information on a geodetic
object, coordinate reference system (CRS) or coordinate operation,
when the -s and -t options are specified, and display it under
different formats (PROJ string, WKT string or PROJJSON string).

It can also be used to query coordinate operations available between
two CRS.

The program is named with some reference to the GDAL gdalsrsinfo
utility that offers partly similar services.

The following control parameters can appear in any order:

-o formats
formats is a comma separated combination of: all, default,
PROJ, WKT_ALL, WKT2:2015, WKT2:2019, WKT1:GDAL, WKT1:ESRI,
PROJJSON, SQL.

Except all and default, other formats can be preceded by - to
disable them.

NOTE:
WKT2_2019 was previously called WKT2_2018.

NOTE:
Before PROJ 6.3.0, WKT1:GDAL was implicitly calling
--boundcrs-to-wgs84. This is no longer the case.

NOTE:
When SQL is specified, --output-id must be specified.

-k crs|operation|datum|ensemble|ellipsoid
When used to query a single object with a AUTHORITY:CODE,
determines the (k)ind of the object in case there are CRS,
coordinate operations or ellipsoids with the same CODE. The
default is crs.

--summary
When listing coordinate operations available between 2 CRS,
return the result in a summary format, mentioning only the
name of the coordinate operation, its accuracy and its area of
use.

NOTE:
only used for coordinate operation computation

-q Turn on quiet mode. Quiet mode is only available for queries
on single objects, and only one output format is selected. In
that mode, only the PROJ, WKT or PROJJSON string is displayed,
without other introduction output. The output is then
potentially compatible of being piped in other utilities.

--area name_or_code
Specify an area of interest to restrict the results when
researching coordinate operations between 2 CRS. The area of
interest can be specified either as a name (e.g "Denmark -
onshore") or a AUTHORITY:CODE (EPSG:3237) This option is
exclusive of --bbox.

NOTE:
only used for coordinate operation computation

--bbox west_long,south_lat,east_long,north_lat
Specify an area of interest to restrict the results when
researching coordinate operations between 2 CRS. The area of
interest is specified as a bounding box with geographic
coordinates, expressed in degrees in a unspecified geographic
CRS. west_long and east_long should be in the [-180,180]
range, and south_lat and north_lat in the [-90,90]. west_long
is generally lower than east_long, except in the case where
the area of interest crosses the antimeridian.

NOTE:
only used for coordinate operation computation

--spatial-test contains|intersects
Specify how the area of use of coordinate operations found in
the database are compared to the area of use specified
explicitly with --area or --bbox, or derived implicitly from
the area of use of the source and target CRS. By default,
projinfo will only keep coordinate operations whose are of use
is strictly within the area of interest (contains strategy).
If using the intersects strategy, the spatial test is relaxed,
and any coordinate operation whose area of use at least partly
intersects the area of interest is listed.

NOTE:
only used for coordinate operation computation

--crs-extent-use none|both|intersection|smallest
Specify which area of interest to consider when no explicit
one is specified with --area or --bbox options. By default
(smallest strategy), the area of use of the source or target
CRS will be looked, and the one that is the smallest one in
terms of area will be used as the area of interest. If using
none, no area of interest is used. If using both, only
coordinate operations that relate (contain or intersect
depending of the --spatial-test strategy) to the area of use
of both CRS are selected. If using intersection, the area of
interest is the intersection of the bounding box of the area
of use of the source and target CRS

NOTE:
only used for coordinate operation computation

--grid-check none|discard_missing|sort|known_available
Specify how the presence or absence of a horizontal or
vertical shift grid required for a coordinate operation
affects the results returned when researching coordinate
operations between 2 CRS. The default strategy is sort (if
PROJ_NETWORK is not defined). In that case, all candidate
operations are returned, but the actual availability of the
grids is used to determine the sorting order. That is, if a
coordinate operation involves using a grid that is not
available in the PROJ resource directories (determined by the
PROJ_DATA environment variable), it will be listed in the
bottom of the results. The none strategy completely disables
the checks of presence of grids and this returns the results
as if all the grids where available. The discard_missing
strategy discards results that involve grids not present in
the PROJ resource directories. The known_available strategy
discards results that involve grids not present in the PROJ
resource directories and that are not known of the CDN. This
is the default strategy is PROJ_NETWORK is set to ON.

NOTE:
only used for coordinate operation computation

--pivot-crs
always|if_no_direct_transformation|never|{auth:code[,auth:code]*}
Determine if intermediate (pivot) CRS can be used when
researching coordinate operation between 2 CRS. A typical
example is the WGS84 pivot. By default, projinfo will consider
any potential pivot if there is no direct transformation (
if_no_direct_transformation). If using the never strategy,
only direct transformations between the source and target CRS
will be used. If using the always strategy, intermediate CRS
will be considered even if there are direct transformations.
It is also possible to restrict the pivot CRS to consider by
specifying one or several CRS by their AUTHORITY:CODE.

NOTE:
only used for coordinate operation computation

--show-superseded
When enabled, coordinate operations that are superseded by
others will be listed. Note that supersession is not
equivalent to deprecation: superseded operations are still
considered valid although they have a better equivalent,
whereas deprecated operations have been determined to be
erroneous and are not considered at all.

NOTE:
only used for coordinate operation computation

--hide-ballpark
New in version 7.1.

Hides any coordinate operation that is, or contains, a
Ballpark transformation

NOTE:
only used for coordinate operation computation

--accuracy {accuracy}
New in version 8.0.

Sets the minimum desired accuracy for returned coordinate
operations.

NOTE:
only used for coordinate operation computation

--allow-ellipsoidal-height-as-vertical-crs
New in version 8.0.

Allows exporting a geographic or projected 3D CRS as a
compound CRS whose vertical CRS represents the ellipsoidal
height.

NOTE:
only used for CRS, and with WKT1:GDAL output format

--boundcrs-to-wgs84
When specified, this option researches a coordinate operation
from the base geographic CRS of the single CRS, source or
target CRS to the WGS84 geographic CRS, and if found, wraps
those CRS into a BoundCRS object. This is mostly to be used
for early-binding approaches.

--authority name
Specify the name of the authority into which to restrict looks
up for objects, when specifying an object by name or when
coordinate operations are computed. The default is to allow
all authorities.

When used with SQL output, this restricts the authorities to
which intermediate objects can belong to (the default is EPSG
and PROJ). Note that the authority of the --output-id option
will also be implicitly added.

--main-db-path path
Specify the name and path of the database to be used by
projinfo. The default is proj.db in the PROJ resource
directories.

--aux-db-path path
Specify the name and path of auxiliary databases, that are to
be combined with the main database. Those auxiliary databases
must have a table structure that is identical to the main
database, but can be partly filled and their entries can refer
to entries of the main database. The option may be repeated
to specify several auxiliary databases.

--identify
When used with an object definition, this queries the PROJ
database to find known objects, typically CRS, that are close
or identical to the object. Each candidate object is
associated with an approximate likelihood percentage. This is
useful when used with a WKT string that lacks a EPSG
identifier, such as ESRI WKT1. This might also be used with
PROJ strings. For example, +proj=utm +zone=31 +datum=WGS84
+type=crs will be identified with a likelihood of 70% to
EPSG:32631

--dump-db-structure
New in version 8.1.

Outputs the sequence of SQL statements to create a new empty
valid auxiliary database. This option can be specified as the
only switch of the utility. If also specifying a CRS object
and the --output-id option, the definition of the object as
SQL statements will be appended.

--list-crs [list-crs-filter]
New in version 8.1.

Outputs a list (authority name:code and CRS name) of the
filtered CRSs from the database. If no filter is provided all
authority names and types of non deprecated CRSs are dumped.
list-crs-filter is a comma separated combination of:
allow_deprecated,geodetic,geocentric,
geographic,geographic_2d,geographic_3d,vertical,projected,compound.
Affected by options --authority, --area, --bbox and
--spatial-test

A visual alternative is the webpage CRS Explorer .

--3d New in version 6.3.

"Promote" 2D CRS(s) to their 3D version, where the vertical
axis is the ellipsoidal height in metres, using the ellipsoid
of the base geodetic CRS. Depending on PROJ versions and the
exact nature of the CRS involved, especially before PROJ 9.1,
a mix of 2D and 3D CRS could lead to 2D or 3D transformations.
Starting with PROJ 9.1, both CRS need to be 3D for vertical
transformation to possibly happen.

--output-id=AUTH:NAME
New in version 8.1.

Identifier to assign to the object (for SQL output).

It is strongly recommended that new objects should not be
added in common registries, such as EPSG, ESRI, IAU, etc.
Users should use a custom authority name instead. If a new
object should be added to the official EPSG registry, users
are invited to follow the procedure explained at
https://epsg.org/dataset-change-requests.html.

Combined with --dump-db-structure, users can create auxiliary
databases, instead of directly modifying the main proj.db
database. See the example how to export to an auxiliary
database.

Those auxiliary databases can be specified through
proj_context_set_database_path() or the PROJ_AUX_DB
environment variable.

--c-ify
For developers only. Modify the string output of the utility
so that it is easy to put those strings in C/C++ code

--single-line
Output PROJ, WKT or PROJJSON strings on a single line, instead
of multiple indented lines by default.

--searchpaths
New in version 7.0.

Output the directories into which PROJ resources will be
looked for (if not using C API such as
proj_context_set_search_paths() that will override them.

--remote-data
New in version 7.0.

Display information regarding if Network capabilities is
enabled, and the related URL.

--s_epoch
New in version 9.4.

Epoch of coordinates in the source CRS, as decimal year. Only
applies to a dynamic CRS.

--t_epoch
New in version 9.4.

Epoch of coordinates in the target CRS, as decimal year. Only
applies to a dynamic CRS.

EXAMPLES

1. Query the CRS object corresponding to EPSG:4326

projinfo EPSG:4326

Output:

PROJ.4 string:
+proj=longlat +datum=WGS84 +no_defs +type=crs

WKT2:2019 string:
GEOGCRS["WGS 84",
DATUM["World Geodetic System 1984",
ELLIPSOID["WGS 84",6378137,298.257223563,
LENGTHUNIT["metre",1]]],
PRIMEM["Greenwich",0,
ANGLEUNIT["degree",0.0174532925199433]],
CS[ellipsoidal,2],
AXIS["geodetic latitude (Lat)",north,
ORDER[1],
ANGLEUNIT["degree",0.0174532925199433]],
AXIS["geodetic longitude (Lon)",east,
ORDER[2],
ANGLEUNIT["degree",0.0174532925199433]],
USAGE[
SCOPE["unknown"],
AREA["World"],
BBOX[-90,-180,90,180]],
ID["EPSG",4326]]

2. List the coordinate operations between NAD27 (designed with its
CRS name) and NAD83 (designed with its EPSG code 4269) within an
area of interest

projinfo -s NAD27 -t EPSG:4269 --area "USA - Missouri"

Output:

DERIVED_FROM(EPSG):1241, NAD27 to NAD83 (1), 0.15 m, USA - CONUS including EEZ

PROJ string:
+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert \
+xy_in=deg +xy_out=rad +step +proj=hgridshift +grids=conus \
+step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1

WKT2:2019 string:
COORDINATEOPERATION["NAD27 to NAD83 (1)",
SOURCECRS[
GEOGCRS["NAD27",
DATUM["North American Datum 1927",
ELLIPSOID["Clarke 1866",6378206.4,294.978698213898,
LENGTHUNIT["metre",1]]],
PRIMEM["Greenwich",0,
ANGLEUNIT["degree",0.0174532925199433]],
CS[ellipsoidal,2],
AXIS["geodetic latitude (Lat)",north,
ORDER[1],
ANGLEUNIT["degree",0.0174532925199433]],
AXIS["geodetic longitude (Lon)",east,
ORDER[2],
ANGLEUNIT["degree",0.0174532925199433]]]],
TARGETCRS[
GEOGCRS["NAD83",
DATUM["North American Datum 1983",
ELLIPSOID["GRS 1980",6378137,298.257222101,
LENGTHUNIT["metre",1]]],
PRIMEM["Greenwich",0,
ANGLEUNIT["degree",0.0174532925199433]],
CS[ellipsoidal,2],
AXIS["geodetic latitude (Lat)",north,
ORDER[1],
ANGLEUNIT["degree",0.0174532925199433]],
AXIS["geodetic longitude (Lon)",east,
ORDER[2],
ANGLEUNIT["degree",0.0174532925199433]]]],
METHOD["CTABLE2"],
PARAMETERFILE["Latitude and longitude difference file","conus"],
OPERATIONACCURACY[0.15],
USAGE[
SCOPE["unknown"],
AREA["USA - CONUS including EEZ"],
BBOX[23.81,-129.17,49.38,-65.69]],
ID["DERIVED_FROM(EPSG)",1241]]

3. Export an object as a PROJJSON string

projinfo GDA94 -o PROJJSON -q

Output:

{
"type": "GeographicCRS",
"name": "GDA94",
"datum": {
"type": "GeodeticReferenceFrame",
"name": "Geocentric Datum of Australia 1994",
"ellipsoid": {
"name": "GRS 1980",
"semi_major_axis": 6378137,
"inverse_flattening": 298.257222101
}
},
"coordinate_system": {
"subtype": "ellipsoidal",
"axis": [
{
"name": "Geodetic latitude",
"abbreviation": "Lat",
"direction": "north",
"unit": "degree"
},
{
"name": "Geodetic longitude",
"abbreviation": "Lon",
"direction": "east",
"unit": "degree"
}
]
},
"area": "Australia - GDA",
"bbox": {
"south_latitude": -60.56,
"west_longitude": 93.41,
"north_latitude": -8.47,
"east_longitude": 173.35
},
"id": {
"authority": "EPSG",
"code": 4283
}
}

4. Exporting the SQL statements to insert a new CRS in an auxiliary
database.

# Get the SQL statements for a custom CRS
projinfo "+proj=merc +lat_ts=5 +datum=WGS84 +type=crs +title=my_crs" --output-id HOBU:MY_CRS -o SQL -q > my_crs.sql
cat my_crs.sql

# Initialize an auxiliary database with the schema of the reference database
echo ".schema" | sqlite3 /path/to/proj.db | sqlite3 aux.db

# Append the content of the definition of HOBU:MY_CRS
sqlite3 aux.db < my_crs.db

# Check that everything works OK
projinfo --aux-db-path aux.db HOBU:MY_CRS

or more simply:

# Create an auxiliary database with the definition of a custom CRS.
projinfo "+proj=merc +lat_ts=5 +datum=WGS84 +type=crs +title=my_crs" --output-id HOBU:MY_CRS --dump-db-structure | sqlite3 aux.db

# Check that everything works OK
projinfo --aux-db-path aux.db HOBU:MY_CRS

Output:

INSERT INTO geodetic_crs VALUES('HOBU','GEODETIC_CRS_MY_CRS','unknown','','geographic 2D','EPSG','6424','EPSG','6326',NULL,0);
INSERT INTO usage VALUES('HOBU','USAGE_GEODETIC_CRS_MY_CRS','geodetic_crs','HOBU','GEODETIC_CRS_MY_CRS','PROJ','EXTENT_UNKNOWN','PROJ','SCOPE_UNKNOWN');
INSERT INTO conversion VALUES('HOBU','CONVERSION_MY_CRS','unknown','','EPSG','9805','Mercator (variant B)','EPSG','8823','Latitude of 1st standard parallel',5,'EPSG','9122','EPSG','8802','Longitude of natural origin',0,'EPSG','9122','EPSG','8806','False easting',0,'EPSG','9001','EPSG','8807','False northing',0,'EPSG','9001',NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,0);
INSERT INTO usage VALUES('HOBU','USAGE_CONVERSION_MY_CRS','conversion','HOBU','CONVERSION_MY_CRS','PROJ','EXTENT_UNKNOWN','PROJ','SCOPE_UNKNOWN');
INSERT INTO projected_crs VALUES('HOBU','MY_CRS','my_crs','','EPSG','4400','HOBU','GEODETIC_CRS_MY_CRS','HOBU','CONVERSION_MY_CRS',NULL,0);
INSERT INTO usage VALUES('HOBU','USAGE_PROJECTED_CRS_MY_CRS','projected_crs','HOBU','MY_CRS','PROJ','EXTENT_UNKNOWN','PROJ','SCOPE_UNKNOWN');

PROJ.4 string:
+proj=merc +lat_ts=5 +lon_0=0 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs +type=crs

WKT2:2019 string:
PROJCRS["my_crs",
BASEGEOGCRS["unknown",
ENSEMBLE["World Geodetic System 1984 ensemble",
MEMBER["World Geodetic System 1984 (Transit)"],
MEMBER["World Geodetic System 1984 (G730)"],
MEMBER["World Geodetic System 1984 (G873)"],
MEMBER["World Geodetic System 1984 (G1150)"],
MEMBER["World Geodetic System 1984 (G1674)"],
MEMBER["World Geodetic System 1984 (G1762)"],
ELLIPSOID["WGS 84",6378137,298.257223563,
LENGTHUNIT["metre",1]],
ENSEMBLEACCURACY[2.0]],
PRIMEM["Greenwich",0,
ANGLEUNIT["degree",0.0174532925199433]],
ID["HOBU","GEODETIC_CRS_MY_CRS"]],
CONVERSION["unknown",
METHOD["Mercator (variant B)",
ID["EPSG",9805]],
PARAMETER["Latitude of 1st standard parallel",5,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8823]],
PARAMETER["Longitude of natural origin",0,
ANGLEUNIT["degree",0.0174532925199433],
ID["EPSG",8802]],
PARAMETER["False easting",0,
LENGTHUNIT["metre",1],
ID["EPSG",8806]],
PARAMETER["False northing",0,
LENGTHUNIT["metre",1],
ID["EPSG",8807]]],
CS[Cartesian,2],
AXIS["(E)",east,
ORDER[1],
LENGTHUNIT["metre",1]],
AXIS["(N)",north,
ORDER[2],
LENGTHUNIT["metre",1]],
ID["HOBU","MY_CRS"]]

5. Get the WKT representation of EPSG:25832 in the WKT1:GDAL output
format and on a single line

projinfo -o WKT1:GDAL --single-line EPSG:25832

Output:

WKT1:GDAL string:
PROJCS["ETRS89 / UTM zone 32N",GEOGCS["ETRS89",DATUM["European_Terrestrial_Reference_System_1989",SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6258"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4258"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",9],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","25832"]]

BUGS

A list of known bugs can be found at
https://github.com/OSGeo/PROJ/issues where new bug reports can be
submitted to.

HOME PAGE

https://proj.org/

AUTHOR

Even Rouault

COPYRIGHT

1983-2024, PROJ contributors

9.5 01 Dec 2024 PROJINFO(1)