Yes, it is possible to calculate the speed of the International Space Station (ISS) if you have its altitude and observe its movement across your field of view. Here's a method to estimate its speed:
Determine the Time Interval: Note the time when the ISS first enters your field of view from the left and the time when it exits your field of view on the right. This will give you the time interval during which you observed the ISS.
Measure the Angular Displacement: Measure the angular displacement of the ISS as it moves from the left side of your field of view to the right. You can use a protractor or any other method to measure the angle covered by the ISS during the observed time interval.
Calculate the Angular Speed: Divide the measured angular displacement by the time interval in seconds to calculate the angular speed of the ISS in degrees per second.
Convert Angular Speed to Linear Speed: To obtain the linear speed of the ISS, you need to convert the angular speed to linear speed. Since the ISS is at a known altitude, you can use basic trigonometry to make this conversion. The linear speed can be calculated using the formula:
Linear Speed = Altitude * (2 * π * Angular Speed) / 360
Here, Altitude is the altitude of the ISS in meters, Angular Speed is the angular speed in degrees per second, π is pi (approximately 3.14159), and 360 is the number of degrees in a full circle.
By following these steps, you can estimate the speed of the ISS as it moves across your field of view. However, please note that this method provides an approximate speed as it relies on visual observation and measurements, which may have inherent limitations and uncertainties.