From 65a67823cbcd5b01d6c20a65ff3965965062f77a Mon Sep 17 00:00:00 2001
From: Theodore Kruczek <theodore.kruczek@gmail.com>
Date: Wed, 10 Jan 2024 21:44:08 -0500
Subject: [PATCH] refactor: :recycle: refactor GroundPosition from Sensor

---
 src/interfaces/GroundPositionParams.ts |  8 +++
 src/objects/GroundPosition.ts          | 75 ++++++++++++++++++++++++++
 src/objects/Sensor.ts                  | 35 +++---------
 3 files changed, 89 insertions(+), 29 deletions(-)
 create mode 100644 src/interfaces/GroundPositionParams.ts
 create mode 100644 src/objects/GroundPosition.ts

diff --git a/src/interfaces/GroundPositionParams.ts b/src/interfaces/GroundPositionParams.ts
new file mode 100644
index 0000000..d01c853
--- /dev/null
+++ b/src/interfaces/GroundPositionParams.ts
@@ -0,0 +1,8 @@
+import { Degrees, Kilometers } from './../types/types';
+
+export interface GroundPositionParams {
+  name?: string;
+  lat: Degrees;
+  lon: Degrees;
+  alt: Kilometers;
+}
diff --git a/src/objects/GroundPosition.ts b/src/objects/GroundPosition.ts
new file mode 100644
index 0000000..d5f7ad8
--- /dev/null
+++ b/src/objects/GroundPosition.ts
@@ -0,0 +1,75 @@
+import { calcGmst, lla2eci, llaRad2ecf } from '../transforms';
+import { Degrees, EcfVec3, EciVec3, Kilometers, LlaVec3, Radians, RaeVec3 } from '../types/types';
+import { DEG2RAD } from '../utils/constants';
+import { GroundPositionParams } from './../interfaces/GroundPositionParams';
+
+import { BaseObject } from './BaseObject';
+import { Satellite } from './Satellite';
+
+export class GroundPosition extends BaseObject {
+  name = 'Unknown Ground Position';
+  lat: Degrees;
+  lon: Degrees;
+  alt: Kilometers;
+
+  constructor(info: GroundPositionParams) {
+    super(info);
+
+    this.validateInputData_(info);
+    Object.keys(info).forEach((key) => {
+      this[key] = info[key];
+    });
+  }
+
+  isSensor(): boolean {
+    return false;
+  }
+
+  rae(sat: Satellite, date: Date = this.time): RaeVec3<Kilometers, Degrees> {
+    return sat.raeOpt(this, date);
+  }
+
+  /**
+   * Calculates ECF position at a given time.
+   *
+   * @optimized
+   */
+  ecf(): EcfVec3<Kilometers> {
+    return llaRad2ecf(this.llaRad());
+  }
+
+  eci(date: Date = this.time): EciVec3<Kilometers> {
+    const { gmst } = calcGmst(date);
+
+    return lla2eci(this.llaRad(), gmst);
+  }
+
+  setTime(date: Date): this {
+    this.time = date;
+
+    return this;
+  }
+
+  llaRad(): LlaVec3<Radians, Kilometers> {
+    return {
+      lat: (this.lat * DEG2RAD) as Radians,
+      lon: (this.lon * DEG2RAD) as Radians,
+      alt: this.alt,
+    };
+  }
+
+  private validateInputData_(info: GroundPositionParams) {
+    this.validateParameter_(info.lat, -90, 90, 'Invalid latitude - must be between -90 and 90');
+    this.validateParameter_(info.lon, -180, 180, 'Invalid longitude - must be between -180 and 180');
+    this.validateParameter_(info.alt, 0, null, 'Invalid altitude - must be greater than 0');
+  }
+
+  private validateParameter_<T>(value: T, minValue: T, maxValue: T, errorMessage: string): void {
+    if (minValue !== null && value < minValue) {
+      throw new Error(errorMessage);
+    }
+    if (maxValue !== null && value > maxValue) {
+      throw new Error(errorMessage);
+    }
+  }
+}
diff --git a/src/objects/Sensor.ts b/src/objects/Sensor.ts
index b9b3d7e..bff2232 100644
--- a/src/objects/Sensor.ts
+++ b/src/objects/Sensor.ts
@@ -1,20 +1,9 @@
-import {
-  Degrees,
-  Kilometers,
-  LlaVec3,
-  Lookangle,
-  PassType,
-  Radians,
-  RaeVec3,
-  SensorParams,
-  SpaceObjectType,
-} from '../types/types';
-import { DEG2RAD } from '../utils/constants';
-
-import { BaseObject } from './BaseObject';
+import { Degrees, Kilometers, Lookangle, PassType, RaeVec3, SensorParams, SpaceObjectType } from '../types/types';
+
+import { GroundPosition } from './GroundPosition';
 import { Satellite } from './Satellite';
 
-export class Sensor extends BaseObject {
+export class Sensor extends GroundPosition {
   name: string;
   type: SpaceObjectType;
   lat: Degrees;
@@ -83,7 +72,7 @@ export class Sensor extends BaseObject {
 
     for (let timeOffset = 0; timeOffset < planningInterval; timeOffset++) {
       const curTime = new Date(startTime + timeOffset * 1000);
-      const rae = this.getRae(sat, curTime);
+      const rae = this.rae(sat, curTime);
 
       const isInView = this.isRaeInFov(rae);
 
@@ -122,10 +111,6 @@ export class Sensor extends BaseObject {
     return msnPlanPasses;
   }
 
-  getRae(sat: Satellite, date: Date = this.time): RaeVec3<Kilometers, Degrees> {
-    return sat.raeOpt(this, date);
-  }
-
   isRaeInFov(rae: RaeVec3<Kilometers, Degrees>): boolean {
     if (rae.el < this.minEl || rae.el > this.maxEl) {
       return false;
@@ -149,7 +134,7 @@ export class Sensor extends BaseObject {
   }
 
   isSatInFov(sat: Satellite, date: Date = this.time): boolean {
-    return this.isRaeInFov(this.getRae(sat, date));
+    return this.isRaeInFov(this.rae(sat, date));
   }
 
   setTime(date: Date): this {
@@ -158,14 +143,6 @@ export class Sensor extends BaseObject {
     return this;
   }
 
-  getLlaRad(): LlaVec3<Radians, Kilometers> {
-    return {
-      lat: (this.lat * DEG2RAD) as Radians,
-      lon: (this.lon * DEG2RAD) as Radians,
-      alt: this.alt,
-    };
-  }
-
   isDeepSpace(): boolean {
     return this.maxRng > 6000;
   }