Add option to enable or disable SRP and Drag estimation

Author: ChristopherRabotin

src/dynamics/drag.rs

@@ -47,6 +47,8 @@ pub struct ConstantDrag {
     pub rho: f64,
     /// Geoid causing the drag
     pub drag_frame: Frame,
+    /// Set to true to estimate the coefficient of drag
+    pub estimate: bool,
 }
 
 impl fmt::Display for ConstantDrag {
@@ -61,7 +63,11 @@ impl fmt::Display for ConstantDrag {
 
 impl ForceModel for ConstantDrag {
     fn estimation_index(&self) -> Option<usize> {
-        Some(7)
+        if self.estimate {
+            Some(7)
+        } else {
+            None
+        }
     }
 
     fn eom(&self, ctx: &Spacecraft, almanac: Arc<Almanac>) -> Result<Vector3<f64>, DynamicsError> {
@@ -94,6 +100,8 @@ pub struct Drag {
     pub density: AtmDensity,
     /// Frame to compute the drag in
     pub drag_frame: Frame,
+    /// Set to true to estimate the coefficient of drag
+    pub estimate: bool,
 }
 
 impl Drag {
@@ -110,6 +118,7 @@ impl Drag {
                     action: "planetary data from third body not loaded",
                 }
             })?,
+            estimate: false,
         }))
     }
 
@@ -124,6 +133,7 @@ impl Drag {
                     action: "planetary data from third body not loaded",
                 }
             })?,
+            estimate: false,
         }))
     }
 }
@@ -140,7 +150,11 @@ impl fmt::Display for Drag {
 
 impl ForceModel for Drag {
     fn estimation_index(&self) -> Option<usize> {
-        Some(8)
+        if self.estimate {
+            Some(7)
+        } else {
+            None
+        }
     }
 
     fn eom(&self, ctx: &Spacecraft, almanac: Arc<Almanac>) -> Result<Vector3<f64>, DynamicsError> {

src/dynamics/solarpressure.rs

@@ -38,6 +38,8 @@ pub struct SolarPressure {
     /// solar flux at 1 AU, in W/m^2
     pub phi: f64,
     pub e_loc: EclipseLocator,
+    /// Set to true to estimate the coefficient of reflectivity
+    pub estimate: bool,
 }
 
 impl SolarPressure {
@@ -66,6 +68,7 @@ impl SolarPressure {
         Ok(Self {
             phi: SOLAR_FLUX_W_m2,
             e_loc,
+            estimate: true,
         })
     }
 
@@ -74,6 +77,16 @@ impl SolarPressure {
         Ok(Arc::new(Self::default_raw(vec![shadow_body], almanac)?))
     }
 
+    /// Accounts for the shadowing of only one body and will set the solar flux at 1 AU to: Phi = 1367.0
+    pub fn default_no_estimation(
+        shadow_body: Frame,
+        almanac: Arc<Almanac>,
+    ) -> Result<Arc<Self>, DynamicsError> {
+        let mut srp = Self::default_raw(vec![shadow_body], almanac)?;
+        srp.estimate = false;
+        Ok(Arc::new(srp))
+    }
+
     /// Must provide the flux in W/m^2
     pub fn with_flux(
         flux_w_m2: f64,
@@ -96,7 +109,11 @@ impl SolarPressure {
 
 impl ForceModel for SolarPressure {
     fn estimation_index(&self) -> Option<usize> {
-        Some(6)
+        if self.estimate {
+            Some(6)
+        } else {
+            None
+        }
     }
 
     fn eom(&self, ctx: &Spacecraft, almanac: Arc<Almanac>) -> Result<Vector3<f64>, DynamicsError> {