Django ordering by Haversine Distance for model with latitude and longitude

haversine.py

from django.db.models import CASCADE, SET_DEFAULT, SET_NULL, PROTECT, QuerySet, Q
from django.db.models.expressions import F
from django.db.models.functions import Cos, Sqrt, ASin


class ExampleModel(models.Model):
    # Example model that could use this function
    latitude = models.FloatField()
    longitude = models.FloatField()
    
  
def order_closest(queryset: QuerySet, latitude: float, longitude: float) -> QuerySet:
    """Annotates the queryset with distance from the given latitude and longitude and orders by that field. Distance is in kilometers"""
    # Adapted for Django from https://stackoverflow.com/a/41337005/5314541
    degree_to_radian = 0.017453292519943295  # 2*pi/360
    earth_diameter = 12742  # Diameter of the earth in kM, use 7912 (earth diameter in miles) to have the calculated distances be in miles    
    
    # convert latitude/longitude to radians
    lat1 = latitude * degree_to_radian
    lon1 = longitude * degree_to_radian
    lat2 = F('latitude') * degree_to_radian
    lon2 = F('longitude') * degree_to_radian

    haversine_function = 0.5 - Cos(lat2 - lat1)/2 + Cos(lat1)*Cos(lat2) * (1 - Cos(lon2 - lon1) / 2)
    distance_function = earth_diameter * ASin(Sqrt(haversine_function))
    return queryset.annotate(haversine_distance=distance_function).order_by('haversine_distance')

if __name__ == '__main__':
    order_closestExampleMode.objects.all()