Question

National City Chula Vista eus 7) The MODIS imager (aboard NASA'S TERRA satellite) orbits at 705 km with an inclination angle of 98.2°. It has a nadir imaging swath of 2330 km across track and 10 km along flight track. For a given fly-over, how long is Chula Vista in view? Imperial Beach Satellite OTAY MESA AN YSIDRO Map data ©2019 INEGI Gogle United States Terms Send feedback 2 mi

Answer 1

The total length of the city is around 4km.

The imaging swath of the satellite is the length of the surface it can view at a given time, which in this case is 2330km. Since the length is a total of 4km, the city will remain in view for a swath width of 2330-3 = 2327km.

Now, the orbital velocity of the planet is given by:

GM

where r is the orbit of radius, G is the gravitational and M is the mass of the earth.

The orbital radius is measured from the center of the Earth.

r = 6378.1 + 705 = 7083.1km = 7.083x10⁶m

M = 5.9x10²⁴km

G = 6.67x10^-11

Thus,

v = (6.67x10^-11x5.9x10²⁴/7.083x10⁶)^1/2 = 7453.84m/s = 7.453km/s

Thus, the total time for which the satellite will be able to view the town is 2327/7.453 = 312.22s