GPS coordinate system (latitude, longitude, altitude) in Drone Programming - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Calculate distance between two GPS points

Given two GPS points with latitude and longitude, what is the output of this code that calculates the approximate distance in kilometers using the Haversine formula?

Drone Programming

from math import radians, sin, cos, sqrt, atan2

def haversine(lat1, lon1, lat2, lon2):
    R = 6371  # Earth radius in km
    dlat = radians(lat2 - lat1)
    dlon = radians(lon2 - lon1)
    a = sin(dlat/2)**2 + cos(radians(lat1)) * cos(radians(lat2)) * sin(dlon/2)**2
    c = 2 * atan2(sqrt(a), sqrt(1 - a))
    return R * c

point1 = (52.2296756, 21.0122287)
point2 = (41.8919300, 12.5113300)
distance = haversine(*point1, *point2)
print(round(distance, 1))

A 879.6

B 1317.5

C 1150.3

D 1420.8

💡 Hint

Remember the Haversine formula calculates great-circle distance between two points on a sphere.

The code uses the Haversine formula correctly and calculates the distance between Warsaw (52.2296756, 21.0122287) and Rome (41.8919300, 12.5113300) as approximately 1317.5 km.

🧠 Conceptual

intermediate

Understanding altitude in GPS coordinates

Which statement correctly describes the altitude value in a GPS coordinate system?

A Altitude is the distance from the equator along the Earth's surface.

B Altitude is the height above the Earth's surface at the given latitude and longitude.

C Altitude is the height above mean sea level at the given latitude and longitude.

D Altitude is the distance from the center of the Earth to the GPS receiver.

💡 Hint

Altitude usually references a standard baseline related to sea level.

Altitude in GPS coordinates is typically measured as height above mean sea level, not just the Earth's surface or center.

🔧 Debug

advanced

Identify the error in GPS coordinate validation

What error will this code raise when validating GPS latitude and longitude values?

Drone Programming

def validate_gps(lat, lon):
    if not (-90 <= lat <= 90):
        raise ValueError("Latitude out of range")
    if not (-180 <= lon <= 180):
        raise ValueError("Longitude out of range")

validate_gps(95, 45)

A ValueError: Latitude out of range

B ValueError: Longitude out of range

C No error, function returns None

D TypeError: unsupported operand type(s) for <=: 'str' and 'int'

💡 Hint

Check the latitude value passed to the function.

The latitude 95 is outside the valid range -90 to 90, so the function raises a ValueError with message 'Latitude out of range'.

📝 Syntax

advanced

Find the syntax error in GPS coordinate unpacking

Which option contains a syntax error when unpacking GPS coordinates from a tuple?

Drone Programming

gps_point = (40.7128, -74.0060, 10.0)

A lat, lon, alt = gps_point

B lat, lon = gps_point[:2]

C lat, lon, alt = gps_point[0], gps_point[1]

D lat, lon, alt = *gps_point

💡 Hint

Check the use of the unpacking operator (*) in assignment.

Option D uses '*gps_point' incorrectly in assignment, which causes a syntax error. The unpacking operator * cannot be used on the right side like this in an assignment.

🚀 Application

expert

Calculate new GPS coordinate after moving north by 1 km

Given a GPS coordinate (latitude, longitude, altitude), which option correctly calculates the new latitude after moving exactly 1 km north, assuming Earth radius 6371 km?

Drone Programming

from math import radians, degrees

def move_north(lat, lon, alt, km):
    R = 6371  # Earth radius in km
    new_lat = lat + degrees(km / R)
    return (new_lat, lon, alt)

start = (0, 0, 0)
result = move_north(*start, 1)
print(tuple(round(x, 6) if isinstance(x, float) else x for x in result))

A (0.008993, 0, 0)

B (0.009, 0, 0)

C (0.0009, 0, 0)

D (0.08993, 0, 0)

💡 Hint

1 degree latitude is approximately 111 km. Use degrees(km / R) to convert km to degrees.

The code converts 1 km to degrees latitude by dividing by Earth's radius and converting radians to degrees. The result is approximately 0.008993 degrees latitude north.