6 files changed, 67 insertions, 3 deletions
diff --git a/modern/src/common/components/PositionValue.js b/modern/src/common/components/PositionValue.js
index 83fc0ef2..f80bc684 100644
--- a/modern/src/common/components/PositionValue.js
+++ b/modern/src/common/components/PositionValue.js
@@ -2,7 +2,7 @@ import React from 'react';
 import { Link } from '@mui/material';
 import { Link as RouterLink } from 'react-router-dom';
 import {
-  formatAlarm, formatBoolean, formatCoordinate, formatCourse, formatDistance, formatNumber, formatPercentage, formatSpeed, formatTime,
+  formatAlarm, formatAltitude, formatBoolean, formatCoordinate, formatCourse, formatDistance, formatNumber, formatPercentage, formatSpeed, formatTime,
 } from '../util/formatter';
 import { useAttributePreference, usePreference } from '../util/preferences';
 import { useTranslation } from './LocalizationProvider';
@@ -18,6 +18,7 @@ const PositionValue = ({ position, property, attribute }) => {
   const value = property ? position[property] : position.attributes[attribute];
 
   const distanceUnit = useAttributePreference('distanceUnit');
+  const altitudeUnit = useAttributePreference('altitudeUnit');
   const speedUnit = useAttributePreference('speedUnit');
   const coordinateFormat = usePreference('coordinateFormat');
 
@@ -35,6 +36,8 @@ const PositionValue = ({ position, property, attribute }) => {
         return formatSpeed(value, speedUnit, t);
       case 'course':
         return formatCourse(value);
+      case 'altitude':
+        return formatAltitude(value, altitudeUnit, t);
       case 'batteryLevel':
         return formatPercentage(value);
       case 'alarm':
diff --git a/modern/src/common/util/converter.js b/modern/src/common/util/converter.js
index 559e68aa..cb21566b 100644
--- a/modern/src/common/util/converter.js
+++ b/modern/src/common/util/converter.js
@@ -54,6 +54,30 @@ export const distanceFromMeters = (value, unit) => value * distanceConverter(uni
 
 export const distanceToMeters = (value, unit) => value / distanceConverter(unit);
 
+const altitudeConverter = (unit) => {
+  switch (unit) {
+    case 'ft':
+      return 3.28084;
+    case 'm':
+    default:
+      return 1;
+  }
+};
+
+export const altitudeUnitString = (unit, t) => {
+  switch (unit) {
+    case 'ft':
+      return t('sharedFeet');
+    case 'm':
+    default:
+      return t('sharedMeters');
+  }
+};
+
+export const altitudeFromMeters = (value, unit) => value * altitudeConverter(unit);
+
+export const altitudeToMeters = (value, unit) => value / altitudeConverter(unit);
+
 const volumeConverter = (unit) => {
   switch (unit) {
     case 'impGal':
diff --git a/modern/src/common/util/formatter.js b/modern/src/common/util/formatter.js
index 034b0401..f36b4d38 100644
--- a/modern/src/common/util/formatter.js
+++ b/modern/src/common/util/formatter.js
@@ -1,6 +1,13 @@
 import moment from 'moment';
 import {
-  distanceFromMeters, distanceUnitString, speedFromKnots, speedUnitString, volumeFromLiters, volumeUnitString,
+  altitudeFromMeters,
+  altitudeUnitString,
+  distanceFromMeters,
+  distanceUnitString,
+  speedFromKnots,
+  speedUnitString,
+  volumeFromLiters,
+  volumeUnitString,
 } from './converter';
 import { prefixString } from './stringUtils';
 
@@ -26,6 +33,8 @@ export const formatCourse = (value) => {
 
 export const formatDistance = (value, unit, t) => `${distanceFromMeters(value, unit).toFixed(2)} ${distanceUnitString(unit, t)}`;
 
+export const formatAltitude = (value, unit, t) => `${altitudeFromMeters(value, unit).toFixed(2)} ${altitudeUnitString(unit, t)}`;
+
 export const formatSpeed = (value, unit, t) => `${speedFromKnots(value, unit).toFixed(2)} ${speedUnitString(unit, t)}`;
 
 export const formatVolume = (value, unit, t) => `${volumeFromLiters(value, unit).toFixed(2)} ${volumeUnitString(unit, t)}`;
diff --git a/modern/src/reports/ChartReportPage.js b/modern/src/reports/ChartReportPage.js
index 977c5158..00edf7b6 100644
--- a/modern/src/reports/ChartReportPage.js
+++ b/modern/src/reports/ChartReportPage.js
@@ -13,7 +13,9 @@ import ReportsMenu from './components/ReportsMenu';
 import usePositionAttributes from '../common/attributes/usePositionAttributes';
 import { useCatch } from '../reactHelper';
 import { useAttributePreference } from '../common/util/preferences';
-import { distanceFromMeters, speedFromKnots, volumeFromLiters } from '../common/util/converter';
+import {
+  altitudeFromMeters, distanceFromMeters, speedFromKnots, volumeFromLiters,
+} from '../common/util/converter';
 import useReportStyles from './common/useReportStyles';
 
 const ChartReportPage = () => {
@@ -23,6 +25,7 @@ const ChartReportPage = () => {
   const positionAttributes = usePositionAttributes(t);
 
   const distanceUnit = useAttributePreference('distanceUnit');
+  const altitudeUnit = useAttributePreference('altitudeUnit');
   const speedUnit = useAttributePreference('speedUnit');
   const volumeUnit = useAttributePreference('volumeUnit');
 
@@ -51,6 +54,9 @@ const ChartReportPage = () => {
               case 'speed':
                 formatted[key] = speedFromKnots(value, speedUnit).toFixed(2);
                 break;
+              case 'altitude':
+                formatted[key] = altitudeFromMeters(value, altitudeUnit).toFixed(2);
+                break;
               case 'distance':
                 formatted[key] = distanceFromMeters(value, distanceUnit).toFixed(2);
                 break;
diff --git a/modern/src/settings/ServerPage.js b/modern/src/settings/ServerPage.js
index 90b854db..ee2d5f31 100644
--- a/modern/src/settings/ServerPage.js
+++ b/modern/src/settings/ServerPage.js
@@ -157,6 +157,17 @@ const ServerPage = () => {
                   </Select>
                 </FormControl>
                 <FormControl>
+                  <InputLabel>{t('settingsAltitudeUnit')}</InputLabel>
+                  <Select
+                    label={t('settingsAltitudeUnit')}
+                    value={item.attributes.altitudeUnit || 'm'}
+                    onChange={(e) => setItem({ ...item, attributes: { ...item.attributes, altitudeUnit: e.target.value } })}
+                  >
+                    <MenuItem value="m">{t('sharedMeters')}</MenuItem>
+                    <MenuItem value="ft">{t('sharedFeet')}</MenuItem>
+                  </Select>
+                </FormControl>
+                <FormControl>
                   <InputLabel>{t('settingsVolumeUnit')}</InputLabel>
                   <Select
                     label={t('settingsVolumeUnit')}
diff --git a/modern/src/settings/UserPage.js b/modern/src/settings/UserPage.js
index 6e637d49..012d5c66 100644
--- a/modern/src/settings/UserPage.js
+++ b/modern/src/settings/UserPage.js
@@ -187,6 +187,17 @@ const UserPage = () => {
                 </Select>
               </FormControl>
               <FormControl>
+                <InputLabel>{t('settingsAltitudeUnit')}</InputLabel>
+                <Select
+                  label={t('settingsAltitudeUnit')}
+                  value={item.attributes.altitudeUnit || 'm'}
+                  onChange={(e) => setItem({ ...item, attributes: { ...item.attributes, altitudeUnit: e.target.value } })}
+                >
+                  <MenuItem value="m">{t('sharedMeters')}</MenuItem>
+                  <MenuItem value="ft">{t('sharedFeet')}</MenuItem>
+                </Select>
+              </FormControl>
+              <FormControl>
                 <InputLabel>{t('settingsVolumeUnit')}</InputLabel>
                 <Select
                   label={t('settingsVolumeUnit')}