diff --git a/ui/src/LimitCameraHeightToDepth.ts b/ui/src/LimitCameraHeightToDepth.ts
index f5ecaeee1..9dd033e76 100644
--- a/ui/src/LimitCameraHeightToDepth.ts
+++ b/ui/src/LimitCameraHeightToDepth.ts
@@ -3,8 +3,8 @@ import type {Scene} from 'cesium';
 
 
 export default class LimitCameraHeightToDepth {
-  private scene: Scene;
-  private depth: number;
+  private readonly scene: Scene;
+  private readonly depth: number;
 
   constructor(scene: Scene, depth: number) {
     this.scene = scene;
diff --git a/ui/src/MapChooser.ts b/ui/src/MapChooser.ts
index f314bb926..5c2406cb1 100644
--- a/ui/src/MapChooser.ts
+++ b/ui/src/MapChooser.ts
@@ -6,8 +6,8 @@ import type {BaseLayerConfig} from './viewer';
 import MainStore from './store/main';
 
 export default class MapChooser {
-  private viewer: Viewer;
-  private config: BaseLayerConfig[];
+  private readonly viewer: Viewer;
+  private readonly config: BaseLayerConfig[];
   public selectedMap: BaseLayerConfig;
   public elements: NgmMapChooser[] = [];
 
diff --git a/ui/src/NavigableVolumeLimiter.ts b/ui/src/NavigableVolumeLimiter.ts
index 3996d7a84..ba2368f59 100644
--- a/ui/src/NavigableVolumeLimiter.ts
+++ b/ui/src/NavigableVolumeLimiter.ts
@@ -7,8 +7,8 @@ import type {Scene, Rectangle} from 'cesium';
  */
 export default class NavigableVolumeLimiter {
   private blockLimiter = false;
-  private boundingSphere: BoundingSphere;
-  private ratioFunction: (height: number) => number;
+  private readonly boundingSphere: BoundingSphere;
+  private readonly ratioFunction: (height: number) => number;
 
   constructor(scene: Scene, rectangle: Rectangle, height: number, ratioFunction: (height: number) => number) {
     this.boundingSphere = BoundingSphere.fromRectangle3D(rectangle, Ellipsoid.WGS84, height);
diff --git a/ui/src/draw/CesiumDraw.ts b/ui/src/draw/CesiumDraw.ts
index 6e5411c9f..2c8aa9f4c 100644
--- a/ui/src/draw/CesiumDraw.ts
+++ b/ui/src/draw/CesiumDraw.ts
@@ -61,10 +61,10 @@ export type DrawEndDetails = {
 }
 
 export class CesiumDraw extends EventTarget {
-  private viewer_: Viewer;
-  private strokeColor_: Color;
-  private strokeWidth_: number;
-  private fillColor_: Color;
+  private readonly viewer_: Viewer;
+  private readonly strokeColor_: Color;
+  private readonly strokeWidth_: number;
+  private readonly fillColor_: Color;
   private eventHandler_: ScreenSpaceEventHandler | undefined;
   private activePoints_: Cartesian3[] = [];
   private activePoint_: Cartesian3 | undefined;
diff --git a/ui/src/elements/dashboard/ngm-add-member-form.ts b/ui/src/elements/dashboard/ngm-add-member-form.ts
index ada09a3e9..0e49d80b4 100644
--- a/ui/src/elements/dashboard/ngm-add-member-form.ts
+++ b/ui/src/elements/dashboard/ngm-add-member-form.ts
@@ -29,7 +29,7 @@ export class NgmAddMemberForm extends LitElementI18n {
     accessor email: string | undefined;
     @state()
     accessor roleNotSelected = false;
-    private roleDropdownItems: DropdownItem[] = [
+    private readonly roleDropdownItems: DropdownItem[] = [
         {title: i18next.t('dashboard_project_viewer'), value: 'viewer'},
         {title: i18next.t('dashboard_project_editor'), value: 'editor'},
     ];
@@ -105,4 +105,4 @@ export class NgmAddMemberForm extends LitElementI18n {
         return this;
     }
 
-}
\ No newline at end of file
+}
diff --git a/ui/src/elements/dashboard/ngm-dashboard.ts b/ui/src/elements/dashboard/ngm-dashboard.ts
index 6f01a184b..c3ab86e00 100644
--- a/ui/src/elements/dashboard/ngm-dashboard.ts
+++ b/ui/src/elements/dashboard/ngm-dashboard.ts
@@ -127,7 +127,7 @@ export class NgmDashboard extends LitElementI18n {
   private geometries: NgmGeometry[] = [];
   private recentlyViewedIds: Array<string> = [];
   private userEmail: string | undefined;
-  private tempKmlDataSource = new CustomDataSource('tempKmlDataSource');
+  private readonly tempKmlDataSource = new CustomDataSource('tempKmlDataSource');
 
   @consume({context: apiClientContext})
   accessor apiClient!: ApiClient;
diff --git a/ui/src/elements/hide-overflow.ts b/ui/src/elements/hide-overflow.ts
index 7cfd3dfec..24db986d6 100644
--- a/ui/src/elements/hide-overflow.ts
+++ b/ui/src/elements/hide-overflow.ts
@@ -4,7 +4,7 @@ import {customElement} from 'lit/decorators.js';
 
 @customElement('hide-overflow')
 export class HideOverflow extends LitElement {
-  private observer: IntersectionObserver;
+  private readonly observer: IntersectionObserver;
 
   constructor() {
     super();
diff --git a/ui/src/elements/ngm-coordinate-popup.ts b/ui/src/elements/ngm-coordinate-popup.ts
index 1756c4b12..e2513a8a1 100644
--- a/ui/src/elements/ngm-coordinate-popup.ts
+++ b/ui/src/elements/ngm-coordinate-popup.ts
@@ -20,7 +20,7 @@ export class NgmCoordinatePopup extends LitElementI18n {
     @state()
     accessor terrainDistance = '';
     private eventHandler: ScreenSpaceEventHandler | undefined;
-    private integerFormat = new Intl.NumberFormat('de-CH', {
+    private readonly integerFormat = new Intl.NumberFormat('de-CH', {
         maximumFractionDigits: 1
     });
 
@@ -98,4 +98,4 @@ export class NgmCoordinatePopup extends LitElementI18n {
     createRenderRoot() {
         return this;
     }
-}
\ No newline at end of file
+}
diff --git a/ui/src/elements/ngm-cursor-information.ts b/ui/src/elements/ngm-cursor-information.ts
index 6ac6f702b..ec909c66c 100644
--- a/ui/src/elements/ngm-cursor-information.ts
+++ b/ui/src/elements/ngm-cursor-information.ts
@@ -22,7 +22,7 @@ export class NgmCursorInformation extends LitElementI18n {
   private unlistenMoveStart: any;
   private unlistenMoveEnd: any;
   // always use the 'de-CH' locale to always have the simple tick as thousands separator
-  private integerFormat = new Intl.NumberFormat('de-CH', {
+  private readonly integerFormat = new Intl.NumberFormat('de-CH', {
     maximumFractionDigits: 1
   });
 
diff --git a/ui/src/elements/ngm-map-configuration.ts b/ui/src/elements/ngm-map-configuration.ts
index fc9d0d5c6..0bd72df6e 100644
--- a/ui/src/elements/ngm-map-configuration.ts
+++ b/ui/src/elements/ngm-map-configuration.ts
@@ -31,7 +31,7 @@ export class NgmMapConfiguration extends LitElementI18n {
   accessor baseMapId = 'ch.swisstopo.pixelkarte-grau';
   @query('ngm-map-chooser')
   accessor mapChooserElement;
-  private debouncedOpacityUpdate = debounce((evt: Event) => this.updateOpacity(Number((<HTMLInputElement>evt.target).value)), 250);
+  private readonly debouncedOpacityUpdate = debounce((evt: Event) => this.updateOpacity(Number((<HTMLInputElement>evt.target).value)), 250);
   private prevExaggeration: number = 1;
 
   constructor() {
diff --git a/ui/src/elements/ngm-nav-tools.ts b/ui/src/elements/ngm-nav-tools.ts
index 462c7b4af..f2ba11549 100644
--- a/ui/src/elements/ngm-nav-tools.ts
+++ b/ui/src/elements/ngm-nav-tools.ts
@@ -58,7 +58,7 @@ export class NgmNavTools extends LitElementI18n {
   private zoomingOut = false;
   private unlistenFromPostRender: Event.RemoveCallback | null = null;
   private eventHandler: ScreenSpaceEventHandler | undefined;
-  private stopZoomFunction: () => void = () => this.stopZoom();
+  private readonly stopZoomFunction: () => void = () => this.stopZoom();
   private refIcon: Entity = new Entity({
     position: Cartesian3.ZERO,
     show: false,
@@ -70,14 +70,14 @@ export class NgmNavTools extends LitElementI18n {
     }
   });
   private moveRef = false;
-  private julianDate = new JulianDate();
+  private readonly julianDate = new JulianDate();
   private axisDataSource: CustomDataSource | undefined;
   private axisCenter: Cartesian3 | undefined;
-  private oldPolylineUpdate: any = PolylineCollection.prototype.update;
-  private xyAxisCalculation = (axis, side) => [this.axisCenter, positionFromPxDistance(this.viewer!.scene, this.axisCenter!, AXIS_LENGTH, axis, side)];
-  private xAxisCallback = new CallbackProperty(() => this.xyAxisCalculation('x', -1), false);
-  private yAxisCallback = new CallbackProperty(() => this.xyAxisCalculation('y', 1), false);
-  private zAxisCallback = new CallbackProperty(() => this.xyAxisCalculation('z', -1), false);
+  private readonly oldPolylineUpdate: any = PolylineCollection.prototype.update;
+  private readonly xyAxisCalculation = (axis, side) => [this.axisCenter, positionFromPxDistance(this.viewer!.scene, this.axisCenter!, AXIS_LENGTH, axis, side)];
+  private readonly xAxisCallback = new CallbackProperty(() => this.xyAxisCalculation('x', -1), false);
+  private readonly yAxisCallback = new CallbackProperty(() => this.xyAxisCalculation('y', 1), false);
+  private readonly zAxisCallback = new CallbackProperty(() => this.xyAxisCalculation('z', -1), false);
   private exaggeration = 1;
 
   constructor() {
diff --git a/ui/src/elements/ngm-side-bar.ts b/ui/src/elements/ngm-side-bar.ts
index 2fc3952a9..01daac880 100644
--- a/ui/src/elements/ngm-side-bar.ts
+++ b/ui/src/elements/ngm-side-bar.ts
@@ -91,7 +91,7 @@ export class SideBar extends LitElementI18n {
   private zoomedToPosition = false;
   private accordionInited = false;
   private shareListenerAdded = false;
-  private shareDownListener = evt => {
+  private readonly shareDownListener = evt => {
     if (!evt.composedPath().includes(this)) this.activePanel = null;
   };
 
diff --git a/ui/src/layers/ngm-layers-item.ts b/ui/src/layers/ngm-layers-item.ts
index e23fe9cbd..9bed758b3 100644
--- a/ui/src/layers/ngm-layers-item.ts
+++ b/ui/src/layers/ngm-layers-item.ts
@@ -38,8 +38,8 @@ export class NgmLayersItem extends LitElementI18n {
   accessor movable = false;
   @query('.menu')
   accessor actionMenu!: HTMLElement;
-  private toggleItemSelection = () => this.movable ? Sortable.utils.select(this) : Sortable.utils.deselect(this);
-  private debouncedOpacityChange = debounce(() => this.changeOpacity(), 250, true);
+  private readonly toggleItemSelection = () => this.movable ? Sortable.utils.select(this) : Sortable.utils.deselect(this);
+  private readonly debouncedOpacityChange = debounce(() => this.changeOpacity(), 250, true);
 
   firstUpdated() {
     $(this.querySelector('.ui.dropdown')!).dropdown();
@@ -166,9 +166,9 @@ export class NgmLayersItem extends LitElementI18n {
             ${i18next.t('dtd_legend')}
           </div>` : ''}
         ${this.config?.geocatId ? html`
-          <a 
-            class="item" 
-            href="${this.geocatLink(this.config.geocatId)}" 
+          <a
+            class="item"
+            href="${this.geocatLink(this.config.geocatId)}"
             target="_blank" rel="noopener">
             Geocat.ch
           </a>` : ''}
diff --git a/ui/src/measure/MeasureTool.ts b/ui/src/measure/MeasureTool.ts
index 939aef444..e5dbd92b7 100644
--- a/ui/src/measure/MeasureTool.ts
+++ b/ui/src/measure/MeasureTool.ts
@@ -28,7 +28,7 @@ export default class MeasureTool {
     private readonly measureDataSource = new CustomDataSource('measure');
     private readonly measureOptions: MeasureOptions;
     private measureToolActive = false;
-    private screenSpaceEventHandler: ScreenSpaceEventHandler | undefined;
+    private readonly screenSpaceEventHandler: ScreenSpaceEventHandler | undefined;
     private measurePositions: Cartesian3[] = [];
     private highlightEntity: Entity | undefined;
     private points: Entity[] = [];
@@ -164,4 +164,4 @@ export default class MeasureTool {
         this.measureDataSource.entities.removeAll();
         this.viewer?.scene.render();
     }
-}
\ No newline at end of file
+}
diff --git a/ui/src/ngm-app-boot.ts b/ui/src/ngm-app-boot.ts
index fa4618c9d..7c13451e5 100644
--- a/ui/src/ngm-app-boot.ts
+++ b/ui/src/ngm-app-boot.ts
@@ -10,7 +10,7 @@ import {ConfigService} from './api/config.service';
 
 @customElement('ngm-app-boot')
 export class NgmAppBoot extends LitElement {
-  private viewerInitialization = new Task(this, {
+  private readonly viewerInitialization = new Task(this, {
     task: async () => {
       const clientConfig = await new ConfigService().getConfig() as ClientConfig;
       if (!clientConfig) {
diff --git a/ui/src/query/ObjectSelector.ts b/ui/src/query/ObjectSelector.ts
index 6febb133b..6a06ea921 100644
--- a/ui/src/query/ObjectSelector.ts
+++ b/ui/src/query/ObjectSelector.ts
@@ -27,8 +27,8 @@ function isTemplateResult(value) {
 }
 
 export default class ObjectSelector {
-  private viewer: Viewer;
-  private scene: Scene;
+  private readonly viewer: Viewer;
+  private readonly scene: Scene;
   selectedObj: any | null = null; // todo improve types
   savedColor: Color | null = null;
 
diff --git a/ui/src/slicer/SlicerArrows.ts b/ui/src/slicer/SlicerArrows.ts
index eb88680ed..5e419ee24 100644
--- a/ui/src/slicer/SlicerArrows.ts
+++ b/ui/src/slicer/SlicerArrows.ts
@@ -69,18 +69,18 @@ export default class SlicerArrows {
 
   private enableInputs = true;
 
-  private scratchBoundingSphere_ = new BoundingSphere();
-  private scratchArrowPosition2d_ = new Cartesian2();
-  private scratchOppositeArrowPosition2d_ = new Cartesian2();
-  private scratchAxisVector2d_ = new Cartesian2();
-  private scratchMouseMoveVector_ = new Cartesian2();
-  private scratchObjectMoveVector2d_ = new Cartesian2();
-  private scratchNewArrowPosition2d_ = new Cartesian2();
-  private axisVector3d = new Cartesian3();
-  private scratchLeft = new Cartesian3();
-  private scratchRight = new Cartesian3();
-  private scratchTop = new Cartesian3();
-  private scratchBottom = new Cartesian3();
+  private readonly scratchBoundingSphere_ = new BoundingSphere();
+  private readonly scratchArrowPosition2d_ = new Cartesian2();
+  private readonly scratchOppositeArrowPosition2d_ = new Cartesian2();
+  private readonly scratchAxisVector2d_ = new Cartesian2();
+  private readonly scratchMouseMoveVector_ = new Cartesian2();
+  private readonly scratchObjectMoveVector2d_ = new Cartesian2();
+  private readonly scratchNewArrowPosition2d_ = new Cartesian2();
+  private readonly axisVector3d = new Cartesian3();
+  private readonly scratchLeft = new Cartesian3();
+  private readonly scratchRight = new Cartesian3();
+  private readonly scratchTop = new Cartesian3();
+  private readonly scratchBottom = new Cartesian3();
 
   private eventHandler: (ScreenSpaceEventHandler | null) = null;
   highlightedArrow: Entity | undefined = undefined;
diff --git a/ui/src/store/auth.ts b/ui/src/store/auth.ts
index c1ba6a919..802aac782 100644
--- a/ui/src/store/auth.ts
+++ b/ui/src/store/auth.ts
@@ -2,7 +2,7 @@ import {BehaviorSubject} from 'rxjs';
 import type {AuthUser} from '../authService';
 
 export default class AuthStore {
-  private static userSubject = new BehaviorSubject<AuthUser | null>(null);
+  private static readonly userSubject = new BehaviorSubject<AuthUser | null>(null);
 
   static get user(): BehaviorSubject<AuthUser | null> {
     return this.userSubject;
diff --git a/ui/src/store/dashboard.ts b/ui/src/store/dashboard.ts
index be2a97f32..5f5dcee7c 100644
--- a/ui/src/store/dashboard.ts
+++ b/ui/src/store/dashboard.ts
@@ -24,12 +24,12 @@ export type ProjectParamSubject = {
 export type ProjectMode = 'edit' | 'viewEdit' | 'viewOnly' | undefined
 
 export default class DashboardStore {
-  private static selectedTopicOrProjectSubject = new BehaviorSubject<Topic | Project | undefined>(undefined);
-  private static viewIndexSubject = new Subject<number | undefined>();
-  private static topicOrProjectParamSubject = new BehaviorSubject<TopicParamSubject | ProjectParamSubject | undefined>(undefined);
-  private static projectModeSubject = new BehaviorSubject<ProjectMode>(undefined);
-  private static geometriesSubject = new Subject<NgmGeometry[]>();
-  private static showSaveOrCancelWarningSubject = new Subject<boolean>();
+  private static readonly selectedTopicOrProjectSubject = new BehaviorSubject<Topic | Project | undefined>(undefined);
+  private static readonly viewIndexSubject = new Subject<number | undefined>();
+  private static readonly topicOrProjectParamSubject = new BehaviorSubject<TopicParamSubject | ProjectParamSubject | undefined>(undefined);
+  private static readonly projectModeSubject = new BehaviorSubject<ProjectMode>(undefined);
+  private static readonly geometriesSubject = new Subject<NgmGeometry[]>();
+  private static readonly showSaveOrCancelWarningSubject = new Subject<boolean>();
 
   static get selectedTopicOrProject(): BehaviorSubject<Topic | Project | undefined> {
     return this.selectedTopicOrProjectSubject;
diff --git a/ui/src/store/draw.ts b/ui/src/store/draw.ts
index 01a137b54..15facd146 100644
--- a/ui/src/store/draw.ts
+++ b/ui/src/store/draw.ts
@@ -2,8 +2,8 @@ import {BehaviorSubject} from 'rxjs';
 import type {CesiumDraw} from '../draw/CesiumDraw';
 
 export default class DrawStore {
-  private static drawSubject = new BehaviorSubject<CesiumDraw | undefined>(undefined);
-  private static drawStateSubject = new BehaviorSubject<boolean>(false);
+  private static readonly drawSubject = new BehaviorSubject<CesiumDraw | undefined>(undefined);
+  private static readonly drawStateSubject = new BehaviorSubject<boolean>(false);
   static measureState = new BehaviorSubject<boolean>(false);
 
   static setDrawState(value: boolean): void {
diff --git a/ui/src/store/main.ts b/ui/src/store/main.ts
index 66ee92b85..d49fad30a 100644
--- a/ui/src/store/main.ts
+++ b/ui/src/store/main.ts
@@ -5,21 +5,21 @@ import {getIonToken, setIonToken} from '../permalink';
 import {IonAsset} from '../api-ion';
 
 export default class MainStore {
-  private static viewerSubject = new BehaviorSubject<Viewer | null>(null);
-  private static mapChooserSubject = new BehaviorSubject<MapChooser | null>(null);
-  private static layersRemovedSubject = new Subject<void>();
-  private static syncMapSubject = new Subject<void>();
-  private static voxelLayerCountSubject = new BehaviorSubject<string[]>([]);
-  private static ionTokenSubject = new BehaviorSubject<string | null>(getIonToken());
-  private static ionAssetSubject = new Subject<IonAsset>();
-  private static removeIonAssetsSubject = new Subject<void>();
+  private static readonly viewerSubject = new BehaviorSubject<Viewer | null>(null);
+  private static readonly mapChooserSubject = new BehaviorSubject<MapChooser | null>(null);
+  private static readonly layersRemovedSubject = new Subject<void>();
+  private static readonly syncMapSubject = new Subject<void>();
+  private static readonly voxelLayerCountSubject = new BehaviorSubject<string[]>([]);
+  private static readonly ionTokenSubject = new BehaviorSubject<string | null>(getIonToken());
+  private static readonly ionAssetSubject = new Subject<IonAsset>();
+  private static readonly removeIonAssetsSubject = new Subject<void>();
   static setUrlLayersSubject = new Subject<void>();
   static syncLayerParams = new Subject<void>();
   /**
    * List of uploaded KML dataSource names. Required to get list of uploaded layers and update properties in batch (e.g. exaggeration)
    * @private
    */
-  private static uploadedKmlListSubject = new BehaviorSubject<string[]>([]);
+  private static readonly uploadedKmlListSubject = new BehaviorSubject<string[]>([]);
 
   static get viewer(): BehaviorSubject<Viewer | null> {
     return this.viewerSubject;
diff --git a/ui/src/store/navTools.ts b/ui/src/store/navTools.ts
index 482dab6ba..6b0affb5f 100644
--- a/ui/src/store/navTools.ts
+++ b/ui/src/store/navTools.ts
@@ -3,11 +3,11 @@ import type {LockType} from '../elements/ngm-cam-configuration';
 import type {Cartesian3} from 'cesium';
 
 export default class NavToolsStore {
-  private static syncTargetPointSubject = new Subject<void>();
-  private static cameraHeightSubject = new Subject<number>();
-  private static hideTargetPointSubject = new Subject<void>();
-  private static navLockTypeSubject = new BehaviorSubject<LockType>('');
-  private static targetPointPositionSubject = new BehaviorSubject<Cartesian3 | undefined>(undefined);
+  private static readonly syncTargetPointSubject = new Subject<void>();
+  private static readonly cameraHeightSubject = new Subject<number>();
+  private static readonly hideTargetPointSubject = new Subject<void>();
+  private static readonly navLockTypeSubject = new BehaviorSubject<LockType>('');
+  private static readonly targetPointPositionSubject = new BehaviorSubject<Cartesian3 | undefined>(undefined);
   static exaggerationChanged = new Subject<number>();
 
   static get syncTargetPoint() {
diff --git a/ui/src/store/query.ts b/ui/src/store/query.ts
index df294f6f4..1ee3eee15 100644
--- a/ui/src/store/query.ts
+++ b/ui/src/store/query.ts
@@ -2,7 +2,7 @@ import {Subject} from 'rxjs';
 import type {QueryResult} from '../query/types';
 
 export default class QueryStore {
-  private static objectInfoSubject = new Subject<QueryResult | undefined>();
+  private static readonly objectInfoSubject = new Subject<QueryResult | undefined>();
 
   static setObjectInfo(attributes: QueryResult | undefined): void {
     if (attributes && !Object.getOwnPropertyNames(attributes).length)
diff --git a/ui/src/store/toolbox.ts b/ui/src/store/toolbox.ts
index 25301a222..2c5e79d66 100644
--- a/ui/src/store/toolbox.ts
+++ b/ui/src/store/toolbox.ts
@@ -20,14 +20,14 @@ export interface GeometryAction {
 export type GeometryCreateOptions = {geometry: NgmGeometry, slice?: boolean};
 
 export default class ToolboxStore {
-  private static slicerSubject = new BehaviorSubject<Slicer | null>(null);
-  private static rtcSubject = new Subject<GeometryCreateOptions>();
-  private static geometriesSubject = new BehaviorSubject<NgmGeometry[]>([]);
-  private static noEditGeometriesSubject = new BehaviorSubject<NgmGeometry[]>([]);
-  private static openedGeometryOptionsSubject = new BehaviorSubject<OpenedGeometryOptions | null>(null);
-  private static sliceGeometrySubject = new BehaviorSubject<NgmGeometry | null | undefined>(null);
-  private static geomActionSubject = new Subject<GeometryAction>();
-  private static syncSliceSubject = new Subject<void>();
+  private static readonly slicerSubject = new BehaviorSubject<Slicer | null>(null);
+  private static readonly rtcSubject = new Subject<GeometryCreateOptions>();
+  private static readonly geometriesSubject = new BehaviorSubject<NgmGeometry[]>([]);
+  private static readonly noEditGeometriesSubject = new BehaviorSubject<NgmGeometry[]>([]);
+  private static readonly openedGeometryOptionsSubject = new BehaviorSubject<OpenedGeometryOptions | null>(null);
+  private static readonly sliceGeometrySubject = new BehaviorSubject<NgmGeometry | null | undefined>(null);
+  private static readonly geomActionSubject = new Subject<GeometryAction>();
+  private static readonly syncSliceSubject = new Subject<void>();
 
   static get slicer(): BehaviorSubject<Slicer | null> {
     return this.slicerSubject;
diff --git a/ui/src/toolbox/GeometryController.ts b/ui/src/toolbox/GeometryController.ts
index 9508feb39..fcecadc13 100644
--- a/ui/src/toolbox/GeometryController.ts
+++ b/ui/src/toolbox/GeometryController.ts
@@ -47,11 +47,11 @@ import {saveAs} from 'file-saver';
 
 export class GeometryController {
   private draw: CesiumDraw | undefined;
-  private toastPlaceholder: HTMLElement;
+  private readonly toastPlaceholder: HTMLElement;
   private viewer: Viewer | null = null;
-  private unlistenEditPostRender: Event.RemoveCallback | undefined;
-  private geometriesDataSource: CustomDataSource;
-  private julianDate = new JulianDate();
+  private readonly unlistenEditPostRender: Event.RemoveCallback | undefined;
+  private readonly geometriesDataSource: CustomDataSource;
+  private readonly julianDate = new JulianDate();
   private selectedArea: Entity | undefined;
   private screenSpaceEventHandler: ScreenSpaceEventHandler | undefined;
   private geometriesCounter: AreasCounter = {
@@ -60,7 +60,7 @@ export class GeometryController {
     rectangle: 0,
     polygon: 0
   };
-  private noEdit: boolean;
+  private readonly noEdit: boolean;
 
   constructor(geometriesDataSource: CustomDataSource, toastPlaceholder: HTMLElement, noEdit = false) {
     this.geometriesDataSource = geometriesDataSource;
diff --git a/ui/src/toolbox/ngm-draw-section.ts b/ui/src/toolbox/ngm-draw-section.ts
index a47bd2a84..512961ff9 100644
--- a/ui/src/toolbox/ngm-draw-section.ts
+++ b/ui/src/toolbox/ngm-draw-section.ts
@@ -24,7 +24,7 @@ export class NgmDrawSection extends LitElementI18n {
   accessor hidden = true;
   @state()
   accessor lineInfo: DrawInfo | undefined;
-  private draw: CesiumDraw | undefined;
+  private readonly draw: CesiumDraw | undefined;
   private drawGeometries = [
     {label: () => i18next.t('tbx_add_point_btn_label'), type: 'point', icon: 'ngm-point-draw-icon'},
     {label: () => i18next.t('tbx_add_line_btn_label'), type: 'line', icon: 'ngm-line-draw-icon'},
diff --git a/ui/src/toolbox/ngm-geometry-edit.ts b/ui/src/toolbox/ngm-geometry-edit.ts
index 6fd79bbd8..fd7db8610 100644
--- a/ui/src/toolbox/ngm-geometry-edit.ts
+++ b/ui/src/toolbox/ngm-geometry-edit.ts
@@ -42,11 +42,11 @@ export class NgmGeometryEdit extends LitElementI18n {
   accessor validLowerLimit = true;
   private editingEntity: Entity | undefined;
   private viewer: Viewer | null | undefined;
-  private minVolumeHeight = 1;
-  private maxVolumeHeight = 30000;
-  private minVolumeLowerLimit = -30000;
-  private maxVolumeLowerLimit = 30000;
-  private julianDate = new JulianDate();
+  private readonly minVolumeHeight = 1;
+  private readonly maxVolumeHeight = 30000;
+  private readonly minVolumeLowerLimit = -30000;
+  private readonly maxVolumeLowerLimit = 30000;
+  private readonly julianDate = new JulianDate();
   private draw: CesiumDraw | undefined;
   private unsubscribeFromChanges: Event.RemoveCallback | undefined;
   private geometriesDataSource: CustomDataSource | undefined;
diff --git a/ui/src/toolbox/ngm-gst-interaction.ts b/ui/src/toolbox/ngm-gst-interaction.ts
index 3e1a89bc0..7de8eff90 100644
--- a/ui/src/toolbox/ngm-gst-interaction.ts
+++ b/ui/src/toolbox/ngm-gst-interaction.ts
@@ -31,8 +31,8 @@ export class NgmGstInteraction extends LitElementI18n {
   @state()
   accessor selectedId: string | undefined;
   private viewer: Viewer | null = null;
-  private minDepth_ = -6000;
-  private maxDepth_ = 1000;
+  private readonly minDepth_ = -6000;
+  private readonly maxDepth_ = 1000;
   private outputFormat: OutputFormat = 'pdf';
   private abortController = new AbortController();
   private extentInited = false;
diff --git a/ui/src/toolbox/ngm-measure.ts b/ui/src/toolbox/ngm-measure.ts
index 7ccf0037c..1d6a796c2 100644
--- a/ui/src/toolbox/ngm-measure.ts
+++ b/ui/src/toolbox/ngm-measure.ts
@@ -17,7 +17,7 @@ export class NgmMeasure extends LitElementI18n {
     @state()
     accessor lineInfo: DrawInfo | undefined;
     private measure: MeasureTool | undefined;
-    private integerFormat = new Intl.NumberFormat('de-CH', {
+    private readonly integerFormat = new Intl.NumberFormat('de-CH', {
         maximumFractionDigits: 1
     });
 
diff --git a/ui/src/toolbox/ngm-point-edit.ts b/ui/src/toolbox/ngm-point-edit.ts
index c72c4a250..4e2de070b 100644
--- a/ui/src/toolbox/ngm-point-edit.ts
+++ b/ui/src/toolbox/ngm-point-edit.ts
@@ -29,7 +29,7 @@ export class NgmPointEdit extends LitElementI18n {
   maxHeight = 30000;
   minDepth = -30000;
   maxDepth = 30000;
-  private julianDate: JulianDate = new JulianDate();
+  private readonly julianDate: JulianDate = new JulianDate();
   private viewer: Viewer | null = null;
 
   @query('.dropdown')
diff --git a/ui/src/toolbox/ngm-toolbox.ts b/ui/src/toolbox/ngm-toolbox.ts
index de85b4837..dcc51845d 100644
--- a/ui/src/toolbox/ngm-toolbox.ts
+++ b/ui/src/toolbox/ngm-toolbox.ts
@@ -44,7 +44,7 @@ export class NgmToolbox extends LitElementI18n {
   geometriesDataSource: CustomDataSource = new CustomDataSource(GEOMETRY_DATASOURCE_NAME);
   noEditGeometriesDataSource: CustomDataSource = new CustomDataSource(NO_EDIT_GEOMETRY_DATASOURCE_NAME);
   private viewer: Viewer | null = null;
-  private julianDate = new JulianDate();
+  private readonly julianDate = new JulianDate();
   private draw: CesiumDraw | undefined;
   private geometryController: GeometryController | undefined;
   private geometryControllerNoEdit: GeometryController | undefined;
diff --git a/ui/src/toolbox/ngm-topo-profile-modal.ts b/ui/src/toolbox/ngm-topo-profile-modal.ts
index d1ea07751..16d9dbe14 100644
--- a/ui/src/toolbox/ngm-topo-profile-modal.ts
+++ b/ui/src/toolbox/ngm-topo-profile-modal.ts
@@ -48,15 +48,15 @@ export class NgmTopoProfileModal extends LitElementI18n {
   @query('.ngm-profile-tooltip')
   accessor profileTooltip;
   private viewer: Viewer | null | undefined;
-  private bisect = bisector((d) => d.domainDist).left;
+  private readonly bisect = bisector((d) => d.domainDist).left;
   private linestring: number[][] | undefined;
   private data: ProfileData[] = [];
   private name: string | undefined;
   private profileInfo: any | undefined;
   private domain: any;
   private distInKM = false;
-  private highlightPointPosition: Cartesian3 = new Cartesian3();
-  private highlightPoint = new Entity({
+  private readonly highlightPointPosition: Cartesian3 = new Cartesian3();
+  private readonly highlightPoint = new Entity({
     position: <any> new CallbackProperty(() => this.highlightPointPosition, false),
     point: {
       show: new CallbackProperty(() => this.showTooltip, false),