Update Orbit Propagator in Attitude Orbit

config/plots/truth/attitude.yml

@@ -24,3 +24,11 @@
 - type: Plot2D
   x: truth.t.s
   y: truth.leader.attitude.q.body_eci.norm
+
+# Projected area along the direction of travel.
+#
+# This is technically a part of the orbit model but only calculated explicitly
+# while attitude dynamics are being simulation as well.
+- type: Plot2D
+  x: truth.t.s
+  y: truth.leader.orbit.S

config/plots/truth/orbit.yml

@@ -25,3 +25,8 @@
 - type: Plot2D
   x: truth.t.s
   y: [truth.leader.orbit.v.ecef.x, truth.leader.orbit.v.ecef.y, truth.leader.orbit.v.ecef.z]
+
+# Plot orbital energies
+- type: Plot2D
+  x: truth.t.s
+  y: [truth.leader.orbit.T, truth.leader.orbit.U, truth.leader.orbit.E]

include/psim/truth/attitude_orbit.hpp

@@ -38,25 +38,27 @@ namespace psim {
 /** @brief Simulates attitude dynamics without fuel slosh and propagates the
  *         orbital state with a Keplerian model in ECI.
  */
-class AttitudeOrbitNoFuelEciGnc
-  : public AttitudeOrbit<AttitudeOrbitNoFuelEciGnc> {
+class AttitudeOrbitNoFuelEcef : public AttitudeOrbit<AttitudeOrbitNoFuelEcef> {
  private:
-  typedef AttitudeOrbit<AttitudeOrbitNoFuelEciGnc> Super;
+  typedef AttitudeOrbit<AttitudeOrbitNoFuelEcef> Super;
   gnc::Ode4<Real, 16> ode;
 
  public:
-  AttitudeOrbitNoFuelEciGnc() = delete;
-  virtual ~AttitudeOrbitNoFuelEciGnc() = default;
+  AttitudeOrbitNoFuelEcef() = delete;
+  virtual ~AttitudeOrbitNoFuelEcef() = default;
 
-  /** @brief Set the frame argument to ECI.
+  /** @brief Set the frame argument to ECEF.
    */
-  AttitudeOrbitNoFuelEciGnc(RandomsGenerator &randoms,
+  AttitudeOrbitNoFuelEcef(RandomsGenerator &randoms,
       Configuration const &config, std::string const &satellite);
 
+  virtual void step() override;
+
+  Real truth_satellite_orbit_T() const;
+  Real truth_satellite_orbit_U() const;
+  Real truth_satellite_orbit_E() const;
   Vector4 truth_satellite_attitude_q_eci_body() const;
   Vector3 truth_satellite_attitude_L() const;
-
-  virtual void step() override;
 };
 } // namespace psim
 

include/psim/truth/attitude_orbit.yml

@@ -31,6 +31,11 @@ params:
           radians per second.
 
 adds:
+    - name: "truth.{satellite}.orbit.S"
+      type: Real
+      comment: >
+          Projected area of the satellite along the direction of travel in
+          meters squared. This value is used for the drag calculation.
     - name: "truth.{satellite}.orbit.r"
       type: Initialized Vector3
       comment: >
@@ -48,6 +53,19 @@ adds:
           kilogram meters per second squared. The coordinate system is
           implementation dependant. Note that this field is zeroed out on each
           simulation step to avoid applying a continuous input.
+    - name: "truth.{satellite}.orbit.T"
+      type: Lazy Real
+      comment: >
+          Satellite's orbital kinetic energy.
+    - name: "truth.{satellite}.orbit.U"
+      type: Lazy Real
+      comment: >
+          Satellite's orbital potential energy.
+    - name: "truth.{satellite}.orbit.E"
+      type: Lazy Real
+      comment: >
+          Satellite's orbital total energy. This is essentially the difference
+          of the kinetic and potential energies.
     - name: "truth.{satellite}.attitude.q.body_eci"
       type: Initialized Vector4
       comment: >
@@ -81,11 +99,13 @@ adds:
           Angular momentum of the spacecraft in the body frame.
 
 gets:
-    - name: "truth.t.s"
-      type: Real
     - name: "truth.dt.s"
       type: Real
+    - name: "truth.earth.w"
+      type: Vector3
+    - name: "truth.earth.w_dot"
+      type: Vector3
     - name: "truth.earth.q.eci_ecef"
       type: Vector4
-    - name: "truth.{satellite}.environment.b.body"
+    - name: "truth.{satellite}.environment.b.eci"
       type: Vector3