Merge pull request #2127 from rouault/projinfo_hide_ballpark

projinfo: add a --hide-ballpark option

3 files changed, 42 insertions, 16 deletions

diff --git a/docs/source/apps/projinfo.rst b/docs/source/apps/projinfo.rst
index 0e54c244..99adbd50 100644
--- a/docs/source/apps/projinfo.rst
+++ b/docs/source/apps/projinfo.rst
@@ -20,8 +20,9 @@ Synopsis
     |    [[--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-    |    [--grid-check none|discard_missing|sort|known_available] [--show-superseded]
+    |    [--grid-check none|discard_missing|sort|known_available]
     |    [--pivot-crs always|if_no_direct_transformation|never|{auth:code[,auth:code]*}]
+    |    [--show-superseded] [--hide-ballpark]
     |    [--boundcrs-to-wgs84]
     |    [--main-db-path path] [--aux-db-path path]*
     |    [--identify] [--3d]
@@ -177,16 +178,6 @@ The following control parameters can appear in any order:
 
     .. note:: only used for coordinate operation computation
 
-.. option:: -show-superseded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-    When enabled, coordinate operations that are superseded by others will be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 Note that supersession is not equivalent to deprecation: superseded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
-
 .. option:: --pivot-crs always|if_no_direct_transformation|never|{auth:code[,auth:code]*}
 
     Determine if intermediate (pivot) CRS can be used when researching coordinate
@@ -201,6 +192,25 @@ The following control parameters can appear in any order:
 
     .. note:: only used for coordinate operation computation
 
+.. option:: --show-superseded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+    When enabled, coordinate operations that are superseded by others will be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 Note that supersession is not equivalent to deprecation: superseded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
+
+.. option:: --hide-ballpark
+
+    .. versionadded:: 7.1
+
+    Hides any coordinate operation that is, or contains, a
+    :term:`Ballpark transformation`
+
+    .. note:: only used for coordinate operation computation
+
 .. option:: --boundcrs-to-wgs84
 
     When specified, this option researches a coordinate operation from the
diff --git a/docs/source/glossary.rst b/docs/source/glossary.rst
index 21dd0f34..883460d4 100644
--- a/docs/source/glossary.rst
+++ b/docs/source/glossary.rst
@@ -6,6 +6,25 @@ Glossary
 
 .. glossary::
 
+    Ballpark transformation
+
+        For a transformation between two geographic CRS, a ballpark
+        transformation is a coordinate operation that only takes into account
+        potential difference of axis orders (long-lat vs lat-long),
+        units (degree vs grads) and  prime meridian (Greewich vs Paris/Rome/other
+        historic prime meridians). It does not attempt any datum shift, hence
+        the "ballpark" qualifier in its name. Its accuracy is unknown, and could
+        lead in some cases to errors of a few hundreds of metres.
+
+        For a transformation between two vertical CRS or a vertical CRS and
+        a geogrpahic CRS, a ballpark transformation only takes into account
+        potential different in units (e.g. metres vs feet). Its accuracy is
+        unknown, and could lead in some cases to errors of a few tens of metres.
+
+        .. note::
+
+            The term "Ballpark transformation" is specific to PROJ.
+
     Pseudocylindrical Projection
 
         Pseudocylindrical projections have the mathematical characteristics of
diff --git a/docs/source/operations/operations_computation.rst b/docs/source/operations/operations_computation.rst
index 1813a010..2836b75c 100644
--- a/docs/source/operations/operations_computation.rst
+++ b/docs/source/operations/operations_computation.rst
@@ -106,11 +106,8 @@ which can be used as an override).
 
 As those results all involve operations that does not have a perfect accuracy and that
 does not cover the area of use of the 2 CRSs, a
-'Ballpark geographic offset from NAD27 to NAD83' operation is synthetized by PROJ.
-This operation is a sort of dummy operation that only takes into account potential
-difference of axis orders (long-lat vs lat-long), units (degree vs grads) and
-prime meridian (Greewich vs Paris/Rome/other historic prime meridians). It does
-not attempt any datum shift, hence the "ballpark" qualifier in its name.
+'Ballpark geographic offset from NAD27 to NAD83' operation is synthetized by PROJ
+(see :term:`Ballpark transformation`)
 
 Filtering and sorting of coordinate operations
 ----------------------------------------------