3 files changed, 62 insertions, 5 deletions

diff --git a/src/iso19111/crs.cpp b/src/iso19111/crs.cpp
index 26725e24..b9b38c80 100644
--- a/src/iso19111/crs.cpp
+++ b/src/iso19111/crs.cpp
@@ -2478,6 +2478,14 @@ void VerticalCRS::_exportToWKT(io::WKTFormatter *formatter) const {
     cs->_exportToWKT(formatter);
     formatter->setOutputAxis(oldAxisOutputRule);
 
+    if (isWKT2 && formatter->use2019Keywords() && !d->geoidModel.empty()) {
+        const auto &model = d->geoidModel[0];
+        formatter->startNode(io::WKTConstants::GEOIDMODEL, false);
+        formatter->addQuotedString(model->nameStr());
+        model->formatID(formatter);
+        formatter->endNode();
+    }
+
     ObjectUsage::baseExportToWKT(formatter);
     formatter->endNode();
 }
@@ -2539,6 +2547,15 @@ void VerticalCRS::_exportToJSON(
     formatter->setOmitTypeInImmediateChild();
     coordinateSystem()->_exportToJSON(formatter);
 
+    if (!d->geoidModel.empty()) {
+        const auto &model = d->geoidModel[0];
+        writer.AddObjKey("geoid_model");
+        auto objectContext2(formatter->MakeObjectContext(nullptr, false));
+        writer.AddObjKey("name");
+        writer.Add(model->nameStr());
+        model->formatID(formatter);
+    }
+
     ObjectUsage::baseExportToJSON(formatter);
 }
 //! @endcond
@@ -2572,7 +2589,8 @@ void VerticalCRS::addLinearUnitConvert(
  * cs::VerticalCS.
  *
  * @param properties See \ref general_properties.
- * At minimum the name should be defined.
+ * At minimum the name should be defined. The GEOID_MODEL property can be set
+ * to a TransformationNNPtr object.
  * @param datumIn The datum of the CRS.
  * @param csIn a VerticalCS.
  * @return new VerticalCRS.
@@ -2592,7 +2610,8 @@ VerticalCRS::create(const util::PropertyMap &properties,
  * One and only one of datum or datumEnsemble should be set to a non-null value.
  *
  * @param properties See \ref general_properties.
- * At minimum the name should be defined.
+ * At minimum the name should be defined. The GEOID_MODEL property can be set
+ * to a TransformationNNPtr object.
  * @param datumIn The datum of the CRS, or nullptr
  * @param datumEnsembleIn The datum ensemble of the CRS, or nullptr.
  * @param csIn a VerticalCS.
@@ -2607,6 +2626,14 @@ VerticalCRS::create(const util::PropertyMap &properties,
                                                       csIn));
     crs->assignSelf(crs);
     crs->setProperties(properties);
+    const auto geoidModelPtr = properties.get("GEOID_MODEL");
+    if (geoidModelPtr) {
+        auto transf = util::nn_dynamic_pointer_cast<operation::Transformation>(
+            *geoidModelPtr);
+        if (transf) {
+            crs->d->geoidModel.emplace_back(NN_NO_CHECK(transf));
+        }
+    }
     return crs;
 }
 
diff --git a/src/iso19111/io.cpp b/src/iso19111/io.cpp
index fc66b6c9..116a8b78 100644
--- a/src/iso19111/io.cpp
+++ b/src/iso19111/io.cpp
@@ -89,7 +89,7 @@ static const std::string emptyString{};
 
 // If changing that value, change it in data/projjson.schema.json as well
 #define PROJJSON_CURRENT_VERSION                                               \
-    "https://proj.org/schemas/v0.1/projjson.schema.json"
+    "https://proj.org/schemas/v0.2/projjson.schema.json"
 //! @endcond
 
 #if 0
@@ -3820,8 +3820,22 @@ CRSNNPtr WKTParser::Private::buildVerticalCRS(const WKTNodeNNPtr &node) {
         ThrowNotExpectedCSType("vertical");
     }
 
+    auto &props = buildProperties(node);
+    auto &geoidModelNode = nodeP->lookForChild(WKTConstants::GEOIDMODEL);
+    if (!isNull(geoidModelNode)) {
+        auto &propsModel = buildProperties(geoidModelNode);
+        const auto dummyCRS = VerticalCRS::create(
+            PropertyMap(), datum, datumEnsemble, NN_NO_CHECK(verticalCS));
+        const auto model(Transformation::create(
+            propsModel, dummyCRS, dummyCRS, nullptr,
+            OperationMethod::create(PropertyMap(),
+                                    std::vector<OperationParameterNNPtr>()),
+            {}, {}));
+        props.set("GEOID_MODEL", model);
+    }
+
     auto crs = nn_static_pointer_cast<CRS>(VerticalCRS::create(
-        buildProperties(node), datum, datumEnsemble, NN_NO_CHECK(verticalCS)));
+        props, datum, datumEnsemble, NN_NO_CHECK(verticalCS)));
 
     if (!isNull(datumNode)) {
         auto &extensionNode = datumNode->lookForChild(WKTConstants::EXTENSION);
@@ -4987,7 +5001,22 @@ VerticalCRSNNPtr JSONParser::buildVerticalCRS(const json &j) {
     if (!verticalCS) {
         throw ParsingException("expected a vertical CS");
     }
-    return VerticalCRS::create(buildProperties(j), datum, datumEnsemble,
+
+    auto props = buildProperties(j);
+    if (j.contains("geoid_model")) {
+        auto geoidModelJ = getObject(j, "geoid_model");
+        auto propsModel = buildProperties(geoidModelJ);
+        const auto dummyCRS = VerticalCRS::create(
+            PropertyMap(), datum, datumEnsemble, NN_NO_CHECK(verticalCS));
+        const auto model(Transformation::create(
+            propsModel, dummyCRS, dummyCRS, nullptr,
+            OperationMethod::create(PropertyMap(),
+                                    std::vector<OperationParameterNNPtr>()),
+            {}, {}));
+        props.set("GEOID_MODEL", model);
+    }
+
+    return VerticalCRS::create(props, datum, datumEnsemble,
                                NN_NO_CHECK(verticalCS));
 }
 
diff --git a/src/iso19111/static.cpp b/src/iso19111/static.cpp
index 824047f0..0ed08c95 100644
--- a/src/iso19111/static.cpp
+++ b/src/iso19111/static.cpp
@@ -274,6 +274,7 @@ DEFINE_WKT_CONSTANT(BASEENGCRS);
 DEFINE_WKT_CONSTANT(BASEPARAMCRS);
 DEFINE_WKT_CONSTANT(BASETIMECRS);
 DEFINE_WKT_CONSTANT(VERSION);
+DEFINE_WKT_CONSTANT(GEOIDMODEL);
 
 DEFINE_WKT_CONSTANT(GEODETICCRS);
 DEFINE_WKT_CONSTANT(GEODETICDATUM);