Merge pull request #48 from ChristopherRabotin/issue-47

Stat OD HW1

.gitignore

@@ -1,3 +1,11 @@
+# Ignore files with no extensions
+# Ignore all
+*
+# Unignore all with extensions
+!*.*
+# Unignore all dirs
+!*/
+# Specific ignoring
 outputdata/
 data/jplhorizon
 env.sh

examples/statOD/hw1/main.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/ChristopherRabotin/smd"
+)
+
+/*
+Create a numerical simulation of a spacecraft in an orbit with a = 7000 km, e = 0.001, i = 30 degrees, Ω = 80 degrees, ω = 40 degrees,
+and an initial true anomaly of ν = 0 degrees. Include only μ and J2 in the dynamics for the system.
+Integrate the system for 24 hours. This is your reference trajectory.
+Integrate a second trajectory by perturbing the initial state with a state deviation vector, δx = [1km, 0, 0, 0, 10m/s, 0].
+Compare the state of the second trajectory with respect to the reference trajectory over the course of 24 hours.
+Use the STM computed around the reference trajectory to perform a second propagation of δx.
+*/
+func main() {
+	dt := time.Now().UTC()
+	osc := smd.NewOrbitFromOE(7000, 0.001, 30, 80, 40, 0, smd.Earth)
+	R, V := osc.RV()
+	fmt.Printf("R=%+v km\tV=%+v km/s\n", R, V)
+	pert := smd.Perturbations{Jn: 2}
+	mis := smd.NewMission(smd.NewEmptySC("hw10", 0), osc, dt, dt.Add(24*time.Hour), smd.Cartesian, pert, smd.ExportConfig{Filename: "hw1.0", Cosmo: true, AsCSV: true, Timestamp: false})
+	mis.Propagate()
+
+	// Second with initial error δx.
+	R[0]++
+	V[1] += 10e-3
+	fmt.Printf("R=%+v km\tV=%+v km/s\n", R, V)
+	osc = smd.NewOrbitFromRV(R, V, smd.Earth)
+	mis = smd.NewMission(smd.NewEmptySC("hw11", 0), osc, dt, dt.Add(24*time.Hour), smd.Cartesian, pert, smd.ExportConfig{Filename: "hw1.1", Cosmo: true, AsCSV: true, Timestamp: false})
+	mis.Propagate()
+}