News¶

7.0.1 Release Notes¶

May 1st 2020

Updates¶

Database: update to EPSG v9.8.9 (#2141)

Bug fixes¶

Make tests independent of proj-datumgrid (#1995)
Add missing projection property tables (#1996)
Avoid crash when running against SQLite3 binary built with -DSQLITE_OMIT_AUTOINIT (#1999)
createOperations(): fix wrong pipeline generation with CRS that has +nadgrids= and +pm= (#2002)
Fix bad copy&replace pattern on HEALPix and rHEALPix projection names (#2007)
createUnitOfMeasure(): use full double resolution for the conversion factor (#2014)
Update README with info on PROJ-data (#2015)
utm/ups: make sure to set errno to PJD_ERR_ELLIPSOID_USE_REQUIRED if +es==0 (#2045)
data/Makefile.am: remove bashism (#2048)
ProjectedCRS::identify(): tune it to better work with ESRI WKT representation of EPSG:2193 (#2059)
Fix build with gcc 4.8.5 (#2066)
Autotools/pkg-conf: Define datarootdir (#2069)
cs2cs: don’t require +to for ‘{source_crs} {target_crs} filename…’ syntax (#2081)
CMake: fix bug with find_package(PROJ) with macOS (#2082)
ESRI WKT import / identification: special case for NAD_1983_HARN_StatePlane_Colorado_North_FIPS_0501 with Foot_US unit (#2088)
ESRI WKT import / identification: special case for NAD_1983_HARN_StatePlane_Colorado_North_FIPS_0501 with Foot_US unit (#2089)
EngineeringCRS: when exporting to WKT1_GDAL, output unit and axis (#2092)
Use jtsk03-jtsk horizontal grid from CDN (#2098)
CMake: prefer to use use PROJ_SOURCE_DIR and PROJ_BINARY_DIR (#2100)
Fix wrong grids file name in esri.sql (#2104)
Fix identification of projected CRS whose name is close but not strictly equal to a ESRI alias (#2106)
Fix working of Helmert transform between the horizontal part of 2 compoundCRS (#2111)
Database: fix registration of custom entries of grid_transformation_custom.sql for geoid grids (#2114)
ESRI_WKT ingestion: make sure to identify to non-deprecated EPSG entry when possible (#2119)
Make sure that importing a Projected 3D CRS from WKT:2019 keeps the base geographic CRS as 3D (#2125)
createOperations(): improve results of compoundCRS to compoundCRS case (#2131)
hgridshift/vgridshift: defer grid opening when grid has already been opened (#2132)
Resolve a few shadowed declaration warnings (#2142)
ProjectedCRS identification: deal with switched 1st/2nd std parallels for LCC_2SP(#2153)
Fix Robinson inverse projection (#2154)
createOperations(): do not remove ballpark transformation if there are only grid based operations, even if they cover the whole area of use (#2156)
createFromCoordinateReferenceSystemCodes(): ‘optimization’ to avoid using C++ exceptions (#2161)
Ingestion of WKT1_GDAL: correctly map ‘Cylindrical_Equal_Area’ (#2167)
Add limited support for non-conformant WKT1 LAS COMPD_CS[] (#2172)
PROJ4 string import: take into correctly non-metre unit when the string looks like the one for WGS 84 / Pseudo Mercator (#2177)
io.hpp: avoid dependency to proj_json_streaming_writer.hpp (#2184)
Fix support of WKT1_GDAL with netCDF rotated pole formulation (#2186)

6.3.2 Release Notes¶

May 1st 2020

Bug fixes¶

validateParameters(): fix false-positive warning on Equidistant Cylindrical (#1947)
proj_create_crs_to_cr(): avoid potential reprojection failures when reprojecting area of use to source and target CRS (#1993)
createOperations(): fix wrong pipeline generation with CRS that has +nadgrids= and +pm= (#2003)
Fix bad copy&replace pattern on HEALPix and rHEALPix projection names (#2006)
createUnitOfMeasure(): use full double resolution for the conversion factor (#2013)
data/Makefile.am: remove bashism (#2047)
:cpp:func:ProjectedCRS::identify: tune it to better work with ESRI WKT representation of EPSG:2193 (#2058)
EngineeringCRS: when exporting to WKT1_GDAL, output unit and axis (#2091)
Add missing entries in grid_alternatives for Portugal grids coming from ESRI entries (#2103)
Fix working of Helmert transform between the horizontal part of 2 compoundCRS (#2110)
ESRI_WKT ingestion: make sure to identify to non-deprecated EPSG entry when possible (#2118)
Make sure that importing a Projected 3D CRS from WKT:2019 keeps the base geographic CRS as 3D (#2124)
createOperations(): improve results of compoundCRS to compoundCRS case (#2130)
PROJ4 string import: take into correctly non-metre unit when the string looks like the one for WGS 84 / Pseudo Mercator (#2178)
Fix support of WKT1_GDAL with netCDF rotated pole formulation (#2187)
io.hpp: avoid dependency to proj_json_streaming_writer.hpp (#2188)

7.0.0 Release Notes¶

March 1st 2020

The major feature in PROJ 7 is significantly improved handling of gridded models. This was implemented in PROJ RFC 4: Remote access to grids and GeoTIFF grids. The main features of the RFC4 work is that PROJ now implements a new grid format, Geodetic TIFF grids, for exchaning gridded transformation models. In addition to the new grid format, PROJ can now also access grids online using a data store in the cloud.

The grids that was previously available via the proj-datumgrid packages are now available in two places:

As a single combined data archive including all available resource files

From the cloud via https://cdn.proj.org

In Addition, provided with PROJ is a utility called projsync that can be used download grids from the data store in the cloud.

The use of the new grid format and the data from the cloud requires that PROJ is build against libtiff and libcurl. Both are optional dependencies to PROJ but it is highly encouraged that the software is build against both.

Warning

PROJ 7 will be last major release version that includes the proj_api.h header. The functionality in proj_api.h is deprecated and only supported in maintenance mode. It is inferior to the functionality provided by functions in the proj.h header and all projects still relying on proj_api.h are encouraged to migrate to the new API in proj.h. See Version 4 to 6 API Migration. for more info on how to migrate from the old to the new API.

Updates¶

Added new file access API to proj.h (#866)
Updated the name of the most recent version of the WKT2 standard from WKT2_2018 to WKT2_2019 to reflect the proper name of the standard (#1585)
Improvements in transformations from/to WGS 84 (Gxxxx) realizations and vertical <–> geog transormations (#1608)
Update to version 1.50 of the geodesic library (#1629)
Promote proj_assign_context() to proj.h from proj_experimental.h (#1630)
Add rotation support to the HEALPix projection (#1638)
Add C function proj_crs_create_bound_vertical_crs() (#1689)
Use Win32 Unicode APIs and expect all strings to be UTF-8 (#1765)
Improved name aliases lookup (#1827)
CMake: Employ better use of CTest with the BUILD_TESTING option (#1870)
Grid correction: fix handling grids spanning antimeridian (#1882)
Remove legacy CMake target name proj (#1883)
projinfo add --searchpaths switch (#1892)
Add +proj=set operation to set component(s) of a coordinate to a fixed value (#1896)
Add EPSG records for ‘Geocentric translation by Grid Interpolation (IGN)’ (gr3df97a.txt) and map them to new +proj=xyzgridshift (#1897)
Remove null grid file as it is now a special hardcoded case in grid code (#1898)
Add projsync utility (#1903)
Make PROJ the CMake project name (#1910)
Use relative directory to locate PROJ resource files (#1921)

Bug fixes¶

Horizontal grid shift: fix failures on points slightly outside a subgrid (#209)
Fix ASAN issue with SQLite3VFS class (#1902)
tests: force use of bash for proj_add_test_script_sh (#1905)

Breaking changes¶

Reject NTV2 files where GS_TYPE != SECONDS (#1294)
On Windows the name of the library is now fixed to proj.lib instead of encoding the version number in the library name (#1581)
Require C99 compiler (#1624)
Remove deprecated JNI bindings (#1825)
Remove -ld option from proj and cs2cs (#1844)
Increase CMake minimum version from 3.5 to 3.9 (#1907)

6.3.1 Release Notes¶

February 11th 2020

Updates¶

Update the EPSG database to version 9.8.6
Database: add mapping for gg10_smv2.mnt and gg10_sbv2.mnt French grids
Database: add mapping for TOR27CSv1.GSB

Bug fixes¶

Fix wrong use of derivingConversionRef() that caused issues with use of +init=epsg:XXXX by GDAL (affecting R spatial libraries) or in MapServer
fix exporting CoordinateSystem to PROJ JSON with ID
projinfo: use No. abbreviation instead of UTF-8 character (#1828)
CompoundCRS::identify(): avoid exception when horiz/vertical part is a BoundCRS
createOperations(): fix dealing with projected 3D CRS whose Z units != metre
WKT1_GDAL export: limit datum name massaging to names matching EPSG (#1835)
unitconvert with mjd time format: avoid potential integer overflow (ossfuzz 20072)
ProjectedCRS::identify(): fix wrong identification of some ESRI WKT linked to units
Database: add a geoid_like value for proj_method column of grid_alternatives, fix related entries and simplify/robustify logic to deal with EPSG ‘Geographic3D to GravityRelatedHeight’ methods
Fix ingestion of +proj=cea with +k_0 (#1881)
Fix performance issue, affecting PROJ.4 string generation of EPSG:7842 (#1913)
Fix identification of ESRI-style datum names starting with D_ but without alias (#1911)
cart: Avoid discontinuity at poles in the inverse case (#1906)
Various updates to make regression test suite pass with gcc on i386 (#1906)

6.3.0 Release Notes¶

January 1st 2020

Updates¶

Database: tune accuracy of Canadian NTv1 file w.r.t NTv2 (#1812)
Modify verbosity level of some debug/trace messages (#1811)
projinfo: no longer call createBoundCRSToWGS84IfPossible() for WKT1:GDAL (#1810)
proj_trans(): add retry logic to select other transformation if the best one fails. (#1809)
BoundCRS::identify(): improvements to discard CRS that aren’t relevant (#1802)
Database: update to IGNF v3.1.0 (#1785)
Build: Only export symbols if building DLL (#1773)
Database: update ESRI entries with ArcGIS Desktop version 10.8.0 database (#1762)
createOperations(): chain operations whose middle CRSs are not identical but have the same datum (#1734)
import/export PROJJSON: support a interpolation_crs key to geoid_model (#1732)
Database: update to EPSG v9.8.4 (#1725)
Build: require SQLite 3.11 (#1721)
Add support for GEOIDMODEL (#1710)
Better filtering based on extent and performance improvements (#1709)

Bug fixes¶

Horizontal grid shift: fix issue on iterative inverse computation when switching between (sub)grids (#1797)
createOperations(): make filtering out of ‘uninteresting’ operations less aggressive (#1788)
Make EPSG:102100 resolve to ESRI:102100 (#1786)
ob_tran: restore traditional handling of +to_meter with pj_transform() and proj utility (#1783)
CRS identification: use case insensitive comparison for authority name (#1780)
normalizeForVisualization() and other methods applying on a ProjectedCRS: do not mess the derivingConversion object of the original object (#1746)
createOperations(): fix transformation computation from/to a CRS with +geoidgrids and +vunits != m (#1731)
Fix proj_assign_context()/pj_set_ctx() with pipelines and alternative coord operations (#1726)
Database: add an auxiliary concatenated_operation_step table to allow arbitrary number of steps (#1696)
Fix errors running gie-based tests in Debug mode on Windo (#1688)

6.2.1 Release Notes¶

November 1st 2019

Updates¶

Update the EPSG database to version 9.8.2

Bug fixes¶

Fixed erroneous spelling of “Potsdam” (#1573)
Calculate y-coordinate correctly in Bertin 1953 in all cases (#1579)
proj_create_crs_to_crs_from_pj(): make the PJ* arguments const PJ* (#1583)
PROJStringParser::createFromPROJString(): avoid potential infinite recursion (#1574)
Avoid core dump when setting ctx==NULL in functions proj_coordoperation_is_instantiable() and proj_coordoperation_has_ballpark_transformation() (#1590)
createOperations(): fix conversion from/to PROJ.4 CRS strings with non-ISO-kosher options and +towgs84/+nadgrids (#1602)
proj_trans_generic(): properly set coordinate time to HUGE_VAL when no value is passed to the function (#1604)
Fix support for +proj=ob_tran +o_proj=lonlat/latlong/latlon instead of only only allowing +o_proj=longlat (#1601)
Improve backwards compatibility of vertical transforms (#1613)
Improve emulation of deprecated +init style initialization (#1614)
cs2cs: autopromote CRS to 3D when there’s a mix of 2D and 3D (#1563)
Avoid divisions by zero in odd situations (#1620)
Avoid compile error on Solaris (#1639)
proj_create_crs_to_crs(): fix when there are only transformations with ballpark steps (#1643)
PROJ string CRS ingester: recognize more unit-less parameters, and general handling of +key=string_value parameters (#1645)
Only call pkg-config in configure when necessary (#1652)
Azimuthal Equidistant: for spherical forward path, go to higher precision ellipsoidal case when the point coordinates are super close to the origin (#1654)
proj_create_crs_to_crs(): remove elimination of Ballpark operations that caused transformation failures in some cases (#1665)
createOperations(): allow transforming from a compoundCRS of a bound verticalCRS to a 2D CRS (#1667)
Avoid segfaults in case of out-of-memory situations (#1679)
createOperations(): fix double vertical unit conversion from CompoundCRS to other CRS when the horizontal part of the projected CRS uses non-metre unit (#1683)(#1683)
importFromWkt(): fix axis orientation for non-standard ESRI WKT (#1690)

6.2.0 Release Notes¶

September 1st 2019

Updates¶

Introduced PROJJSON, a JSON encoding of WKT2 (#1547)

Support CRS instantiation of OGC URN’s (#1505)

Expose scope and remarks of database objects (#1537)

EPSG Database updated to version 9.7.0 (#1558)

Added C API function proj_grid_get_info_from_database() (#1494)

Added C API function proj_operation_factory_context_set_discard_superseded() (#1534)

Added C API function proj_context_set_autoclose_database() (#1566)

Added C API function proj_create_crs_to_crs_from_pj() (#1567)

Added C API function proj_cleanup() (#1569)

Bug Fixes¶

Fixed build failure on Solaris systems (#1554)

6.1.1 Release Notes¶

July 1st 2019

Updates¶

Update EPSG registry to version 9.6.3 (#1485)

Bug Fixes¶

Take the passed authority into account when identifying objects (#1466)
Avoid exception when transforming from NAD83 to projected CRS using NAD83(2011) (#1477)
Avoid off-by-one reading of name argument if name of resource file has length 1 (#11489)
Do not include PROJ_LIB in proj_info().searchpath when context search path is set (#1498)
Use correct delimeter for the current platform when parsing PROJ_LIB (#1497)
Do not confuse ‘ID74’ CRS with WKT2 ID[] node (#1506)
WKT1 importer: do case insensitive comparison for axis direction (#1509)
Avoid compile errors on GCC 4.9.3 (#1512)
Make sure that pipelines including +proj=ob_tran can be created (#1526)

6.1.0 Release Notes¶

May 15th 2019

Updates¶

Include custom ellipsoid definitions from QGIS (#1137)
Add -k ellipsoid option to projinfo (#1338)
Make cs2cs support 4D coordinates (#1355)
WKT2 parser: update to OGC 18-010r6 (#1360 #1366))
Update internal version of googletest to v1.8.1 (#1361)
Database update: EPSG v9.6.2 (#1462), IGNF v3.0.3, ESRI 10.7.0 and add operation_version column (#1368)
Add proj_normalize_for_visualization() that attempts to apply axis ordering as used by most GIS applications and PROJ <6 (#1387)
Added noop operation (#1391)
Paths set by user take priority over PROJ_LIB for search paths (#1398)
Reduced database size (#1438)
add support for compoundCRS and concatenatedOperation named from their components (#1441)

Bug fixes¶

Have gie return non-zero code when file can’t be opened (#1312)
CMake cross-compilation fix (#1316)
Use 1st eccentricity instead of 2nd eccentricity in Molodensky (#1324)
Make sure to include grids when doing Geocentric to CompoundCRS with nadgrids+geoidgrids transformations (#1326)
Handle coordinates outside of bbox better (#1333)
Enable system error messages in command line automatically in builds (#1336)
Make sure to install projinfo man page with CMake (#1347)
Add data dir to pkg-config file proj.pc (#1348)
Fix GCC 9 warning about useless std::move() (#1352)
Grid related fixes (#1369)
Make sure that ISO19111 C++ code sets pj_errno on errors (#1405)
vgridshift: handle longitude wrap-around for grids with 360deg longitude extent (#1429)
proj/cs2cs: validate value of -f parameter to avoid potential crashes (#1434)
Many division by zero and similar bug fixes found by OSS Fuzz.

6.0.0 Release Notes¶

March 1st 2019

PROJ 6 has undergone extensive changes to increase its functional scope from a cartographic projection engine with so-called “early-binding” geodetic datum transformation capabilities to a more complete library supporting coordinate transformations and coordinate reference systems.

As a foundation for other enhancements, PROJ now includes a C++ implementation of the modelisation propopsed by the ISO-19111:2019 standard / OGC Abstract Specification Topic 2: “Referencing By Coordinates”, for geodetic reference frames (datums), coordinate reference systems and coordinate operations. Construction and query of those geodetic objects is available through a new C++ API, and also accessible for the most part from bindings in the C API.

Those geodetic objects can be imported and exported from and into the OGC Well-Known Text format (WKT) in its different variants: ESRI WKT, GDAL WKT 1, WKT2:2015 (ISO 19162:2015) and WKT2:2018 (ISO 19162:2018). Import and export of CRS objects from and into PROJ strings is also supported. This functionality was previously available in the GDAL software library (except WKT2 support which is a new feature), and is now an integral part of PROJ.

A unified database of geodetic objects, coordinate reference systems and their metadata, and coordinate operations between those CRS is now available in a SQLite3 database file, proj.db. This includes definitions imported from the IOGP EPSG dataset (v9.6.0 release), the IGNF (French national mapping agency) geodetic registry and the ESRI projection engine database. PROJ is now the reference software in the “OSGeo C stack” for this CRS and coordinate operation database, whereas previously this functionality was spread over PROJ, GDAL and libgeotiff, and used CSV or other adhoc text-based formats.

Late-binding coordinate operation capabilities, that takes metadata such as area of use and accuracy into account, has been added. This can avoid in a number of situations the past requirement of using WGS84 as a pivot system, which could cause unneeded accuracy loss, or was not doable at all sometimes when transformation to WGS84 was not available. Those late-binding capabilities are now used by the proj_create_crs_to_crs() function and the cs2cs utility.

A new command line utility, projinfo, has been added to query information about a geodetic object of the database, import and export geodetic objects from/into WKT and PROJ strings, and display coordinate operations available between two CRSs.

UPDATES¶

Removed projects.h as a public interface (#835)
Deprecated the proj_api.h interface. The header file is still available but will be removed with the next major version release of PROJ. It is now required to define ACCEPT_USE_OF_DEPRECATED_PROJ_API_H before the interface can be used (#836)
Removed support for the nmake build system (#838)
Removed support for the proj_def.dat defaults file (#201)
C++11 required for building PROJ (#1203)
Added build dependency on SQLite 3.7 (#1175)
Added projinfo command line application (#1189)
Added many functions to proj.h for handling ISO19111 functionality (#1175)
Added C++ API exposing ISO19111 functionality (#1175)
Updated cs2cs to use late-binding features (#1182)
Removed the nad2bin application. Now available in the proj-datumgrid git repository (#1236)
Removed support for Chebyshev polynomials in proj (#1226)
Removed proj_geocentric_latitude() from proj.h API (#1170)
Changed behaviour of proj: Now only allow initialization of projections (#1162)
Changed behaviour of tmerc: Now defaults to the Extended Transverse Mercator algorithm (etmerc). Old implementation available by adding +approx (#404)
Chaged behaviour: Default ellipsoid now set to GRS80 (was WGS84) (#1210)
Allow multiple directories in PROJ_LIB environment variable (#1281)
Added Lambert Conic Conformal (2SP Michigan) projection (#1142)
Added Bertin1953 projection (#1133)
Added Tobler-Mercator projection (#1153)
Added Molodensky-Badekas transform (#1160)
Added push and pop coordinate operations (#1250)
Removed +t_obs parameter from helmert and deformation (#1264)
Added +dt parameter to deformation as replacement for removed +t_obs (#1264)

BUG FIXES¶

Read +towgs84 values correctly on locales not using dot as comma separator (#1136)
Fixed file offset for reading of shift values in NTv1 files (#1144)
Avoid problems with PTHREAD_MUTEX_RECURSIVE when using CMake (#1158)
Avoid raising errors when setting ellipsoid flattening to zero (#1191)
Fixed lower square calculations in rHealpix projection (#1206)
Allow Molodensky transform parameters to be zero (#1194)
Fixed wrong parameter in ITRF2000 init file (#1240)
Fixed use of grid paths including spaces (#1152)
Robinson: fix wrong values for forward path for latitudes >= 87.5, and fix inaccurate inverse method (#1172)

PROJ 5.2.0¶

September 15th 2018

UPDATES¶

Added support for deg, rad and grad in unitconvert (#1054)
Assume +t_epoch as time input when not otherwise specified (#1065)
Added inverse Lagrange projection (#1058)
Added +multiplier option to vgridshift (#1072)
Added Equal Earth projection (#1085)
Added “require_grid” option to gie (#1088)
Replace +transpose option of Helmert transform with +convention. From now on the convention used should be explicitly written. An error will be returned when using the +transpose option (#1091)
Improved numerical precision of inverse spherical Mercator projection (#1105)
cct will now forward text after coordinate input to output stream (#1111)

BUG FIXES¶

Do not pivot over WGS84 when doing cs2cs-emulation with geocent (#1026)
Do not scan past the end of the read data in pj_ctx_fgets() (#1042)
Make sure proj_errno_string() is available in DLL (#1050)
Respect +to_meter setting when doing cs2cs-emulation (#1053)
Fixed unit conversion factors for geod (#1075)
Fixed test failures related to GCC 8 (#1084)
Improved handling of +geoc flag (#1093)
Calculate correct projection factors for Webmercator (#1095)
cs2cs now always outputs degrees when transformed coordinates are in angular units (#1112)

PROJ 5.1.0¶

June 1st 2018

UPDATES¶

Function proj_errno_string() added to proj.h API (#847)
Validate units between pipeline steps and ensure transformation sanity (#906)
Print help when calling cct and gie without arguments (#907)
CITATION file added to source distribution (#914)
Webmercator operation added (#925)
Enhanced numerical precision of forward spherical Mercator near the Equator (#928)
Added --skip-lines option to cct (#923)
Consistently return NaN values on NaN input (#949)
Removed unused src/org_proj4_Projections.h file (#956)
Java Native Interface bindings updated (#957, #969)
Horizontal and vertical gridshift operations extended to the temporal domain (#1015)

BUG FIXES¶

Handle NaN float cast overflow in PJ_robin.c and nad_intr.c (#887)
Avoid overflow when Horner order is unreasonably large (#893)
Avoid unwanted NaN conversions in etmerc (#899)
Avoid memory failure in gie when not specifying x,y,z in gie files (#902)
Avoid memory failure when +sweep is initialized incorrectly in geos (#908)
Return HUGE_VAL on erroneous input in ortho (#912)
Handle commented lines correctly in cct (#933)
Avoid segmentation fault when transformation coordinates outside grid area in deformation (#934)
Avoid doing false easting/northing adjustments on cartesian coordinates (#936)
Thread-safe creation of proj mutex (#954)
Avoid errors when setting up geos with +lat_0!=0 (#986)
Reset errno when running proj in verbose mode (#988)
Do not interpolate node values at nodata value in vertical grid shifts (#1004)
Restrict Horner degrees to positive integer values to avoid memory allocation issues (#1005)

PROJ 5.0.1¶

March 1st 2018

Bug fixes¶

Handle ellipsoid change correctly in pipelines when +towgs84=0,0,0 is set (#881)
Handle the case where nad_ctable2_init returns NULL (#883)
Avoid shadowed declaration errors with old gcc (#880)
Expand +datum properly in pipelines (#872)
Fail gracefully when incorrect headers are encountered in grid files (#875)
Improve roundtrip stability in pipelines using +towgs84 (#871)
Fixed typo in gie error codes (#861)
Numerical stability fixes to the geodesic package (#826 & #843)
Make sure that transient errors are returned correctly (#857)
Make sure that locally installed header files are not used when building PROJ (#849)
Fix inconsistent parameter names in proj.h/proj_4D_api.c (#842)
Make sure +vunits is applied (#833)
Fix incorrect Web Mercator transformations (#834)

PROJ 5.0.0¶

February 1st 2018

This version of PROJ introduces some significant extensions and improvements to (primarily) the geodetic functionality of the system.

The main driver for introducing the new features is the emergence of dynamic reference frames, the increasing use of high accuracy GNSS, and the related growing demand for accurate coordinate transformations. While older versions of PROJ included some geodetic functionality, the new framework lays the foundation for turning PROJ into a generic geospatial coordinate transformation engine.

The core of the library is still the well established projection code. The new functionality is primarily exposed in a new programming interface and a new command line utility, cct (for “Coordinate Conversion and Transformation”). The old programming interface is still available and can - to some extent - use the new geodetic transformation features.

The internal architecture has also seen many changes and much improvement. So far, these improvements respect the existing programming interface. But the process has revealed a need to simplify and reduce the code base, in order to support sustained active development.

Therefore we have scheduled regular releases over the coming years which will gradually remove the old programming interface.

This will cause breaking changes with the next two major version releases, which will affect all projects that depend on PROJ (cf. section “deprecations” below).

The decision to break the existing API has not been easy, but has ultimately been deemed necessary to ensure the long term survival of the project. Not only by improving the maintainability immensely, but also by extending the potential user (and hence developer) community.

The end goal is to deliver a generic coordinate transformation software package with a clean and concise code base appealing to both users and developers.

Versioning and naming¶

For the first time in more than 25 years the major version number of the software is changed. The decision to do this is based on the many new features and new API. While backwards compatibility remains - except in a few rare corner cases - the addition of a new and improved programming interface warrants a new major release.

The new major version number unfortunately leaves the project in a bit of a conundrum regarding the name. For the majority of the life-time of the product it has been known as PROJ.4, but since we have now reached version 5 the name is no longer aligned with the version number.

Hence we have decided to decouple the name from the version number and from this version and onwards the product will simply be called PROJ.

In recognition of the history of the software we are keeping PROJ.4 as the name of the organizing project. The same project team also produces the datum-grid package.

In summary:

The PROJ.4 project provides the product PROJ, which is now at version 5.0.0.
The foundational component of PROJ is the library libproj.
Other PROJ components include the application proj, which provides a command line interface to libproj.
The PROJ.4 project also distributes the datum-grid package, which at the time of writing is at version 1.6.0.

Updates¶

Introduced new API in proj.h.
- The new API is orthogonal to the existing proj_api.h API and the internally used projects.h API.
- The new API adds the ability to transform spatiotemporal (4D) coordinates.
- Functions in the new API use the proj_ namespace.
- Data types in the new API use the PJ_ namespace.
Introduced the concept of “transformation pipelines” that makes possible to do complex geodetic transformations of coordinates by daisy chaining simple coordinate operations.
Introduced cct, the Coordinate Conversion and Transformation application.
Introduced gie, the Geospatial Integrity Investigation Environment.
- Selftest invoked by -C flag in proj has been removed
- Ported approx. 1300 built-in selftests to gie format
- Ported approx. 1000 tests from the gigs test framework
- Added approx. 200 new tests
Adopted terminology from the OGC/ISO-19100 geospatial standards series. Key definitions are:
- At the most generic level, a coordinate operation is a change of coordinates, based on a one-to-one relationship, from one coordinate reference system to another.
- A transformation is a coordinate operation in which the two coordinate reference systems are based on different datums, e.g. a change from a global reference frame to a regional frame.
- A conversion is a coordinate operation in which both coordinate reference systems are based on the same datum, e.g. change of units of coordinates.
- A projection is a coordinate conversion from an ellipsoidal coordinate system to a plane. Although projections are simply conversions according to the standard, they are treated as separate entities in PROJ as they make up the vast majority of operations in the library.
New operations
- The pipeline operator (pipeline)
- Transformations
  
  Helmert transform (helmert)
  
  Horner real and complex polynomial evaluation (horner)
  
  Horizontal gridshift (hgridshift)
  
  Vertical gridshift (vgridshift)
  
  Molodensky transform (molodensky)
  
  Kinematic gridshift with deformation model (deformation)
- Conversions
  
  Unit conversion (unitconvert)
  
  Axis swap (axisswap)
- Projections
  
  Central Conic projection (ccon)
Significant documentation updates, including
- Overhaul of the structure of the documentation
- A better introduction to the use of PROJ
- A complete reference to the new API
- a complete rewrite of the section on geodesic calculations
- Figures for all projections
New “free format” option for operation definitions, which permits separating tokens by whitespace when specifying key/value- pairs, e.g. proj = merc lat_0 = 45.
Added metadata to init-files that can be read with the proj_init_info() function in the new proj.h API.
Added ITRF2000, ITRF2008 and ITRF2014 init-files with ITRF transformation parameters, including plate motion model parameters.
Added ellipsoid parameters for GSK2011, PZ90 and “danish”. The latter is similar to the already supported andrae ellipsoid, but has a slightly different semimajor axis.
Added Copenhagen prime meridian.
Updated EPSG database to version 9.2.0.
Geodesic library updated to version 1.49.2-c.
Support for analytical partial derivatives has been removed.
Improved performance in Winkel Tripel and Aitoff.
Introduced pj_has_inverse() function to proj_api.h. Checks if an operation has an inverse. Use this instead of checking whether P->inv exists, since that can no longer be relied on.
ABI version number updated to 13:0:0.
Removed support for Windows CE.
Removed the VB6 COM interface.

Bug fixes¶

Fixed incorrect convergence calculation in Lambert Conformal Conic. (#16)
Handle ellipsoid parameters correctly when using +nadgrids=@null. (#22)
Return correct latitude when using negative northings in Transverse Mercator. (#138)
Return correct result at origin in inverse Mod. Stereographic of Alaska. (#161)
Return correct result at origin in inverse Mod. Stereographic of 48 U.S. (#162)
Return correct result at origin in inverse Mod. Stereographic of 50 U.S. (#163)
Return correct result at origin in inverse Lee Oblated Stereographic. (#164)
Return correct result at origin in inverse Miller Oblated Stereographic. (#165)
Fixed scaling and wrap-around issues in Oblique Cylindrical Equal Area. (#166)
Corrected a coefficient error in inverse Transverse Mercator. (#174)
Respect -r flag when calling proj with -V. (#184)
Remove multiplication by 2 at the equator error in Stereographic projection. (#194)
Allow +alpha=0 and +gamma=0 when using Oblique Mercator. (#195)
Return correct result of inverse Oblique Mercator when alpha is between 90 and 270. (#331)
Avoid segmentation fault when accessing point outside grid. (#396)
Avoid segmentation fault on NaN input in Robin inverse. (#463)
Very verbose use of proj (-V) on Windows is fixed. (#484)
Fixed memory leak in General Oblique Transformation. (#497)
Equations for meridian convergence and partial derivatives have been corrected for non-conformal projections. (#526)
Fixed scaling of cartesian coordinates in pj_transform(). (#726)
Additional bug fixes courtesy of Google’s OSS-Fuzz program