Due: October 28, 2003.

Given:

• broadcast ephemeris file (note: this is the same file you used for the satellite clock corrections)
• READnav_orbit.m Matlab code to read the "Keplerian" elements from the navigation message.
• Kepler's equation homework
• NEW orbits for PRN 24 (YOU MUST PICK UP THIS FILE)

• Read the navigation message using READnav_orbit. Save these values in the variable name bele_gl. Define this as a global variable.
• Code up the broadcast ephemeris algorithm as a function.
• Input must be PRN number and time (GPS seconds).
• Output must be the Cartesian satellite position (a 3 by 1 column vector in meters) and the relativity correction (in meters).

• Use your function to compute satellite coordinates for January 1, 2001 from 0:00 to 1:00 UTC at 30 second increments. Compare your orbits to mine, and plot the difference between them, i.e. delta X, delta Y, delta Z. Microns (1/1000 of a mm) are a good unit for this.
• Use your function to compute satellite coordinates for December 31, 2000, 23 hours, 45 minutes, and 0 seconds. Print to the screen with a precision of 1 mm.

Answers for January 1, 2001, 0:00:00

• Mean anomaly 1.631803886
• Eccentric anomaly 1.641165073
• Uncorrected Argument of latitude -0.003394275054
• Longitude/Ascending Node -8.317126056
• X -11918706.6271945
• Y -23755879.4206037
• Z -75141.8219498

Turn in: plot, code, screen printout.