1_Constellation_Transits.py

import streamlit as st
import constellation_utils as const_utils
import location_utils as loc_utils
import pandas as pd
from datetime import (datetime as dt, timedelta)
from pytz import timezone

# Meta Info
st.set_page_config(page_title='Constellation Transit Finder', page_icon="🔭", initial_sidebar_state='expanded')
st.subheader('Constellation Transits 🛰 🛰 🛰')
st.caption(''' Explore transits of satellites from the biggest constellations 
for over any area on Earth. Visualize constellation specific statistics such as 
satellites launched per year, inclination and altitude distributions!
''')
st.write('Constellation Transit Summary')

# After main page title
def get_results(constObj):
    # After constellation data is retrieved, compute transits
    if constObj.initialized and usrLoc.initialized:
        constObj.generatePasses(usrLoc)
        constObj.showStats(usrLoc)
    else:
        st.error('Will need to fix issues before we can proceed.')

def update_events(const_to_change):
    # Used a callback to drop events for stale loc, timerange
    const_to_change.dropEvents()

# UI Elements
# ------------------------- Sidebar panel
# Get user input:
st.sidebar.write('Begin here 👇')

# 1. Get Constellation
constellationChoice = st.sidebar.selectbox('Select a Constellation', const_utils.CONSTELLATIONS)
# @st.experimental_singleton(ttl=1200) # this will cache satellite data so we do not keep making requests to Celestrak
def getCachedConstellation(constellationName):
    constellation = const_utils.SatConstellation(constellationName)
    return constellation
constellation = getCachedConstellation(constellationChoice)
if constellation.initialized:
    st.sidebar.success(f"Queried {constellation.query_sat_count} {constellation.constellation} satellites.", icon="✅")

# 2. Get Location 
usrLoc = loc_utils.UserLocation()
locationChoice = st.sidebar.selectbox('Select a Location', usrLoc.locations_list, on_change=update_events, args=(constellation,))
usrLoc.initialize_location_services(locationChoice)
lat_long_input_disabled = True
if locationChoice == "CUSTOM LOCATION":
    lat_long_input_disabled = False
st.sidebar.columns(2)
lat = st.sidebar.number_input('Latitude', min_value= -90.0, max_value= 90.0, value=usrLoc.locations_dict[usrLoc.selected_loc][0], disabled=lat_long_input_disabled, on_change=update_events, args=(constellation,))
lon = st.sidebar.number_input('Longitude', min_value= -180.0, max_value=180.0, value=usrLoc.locations_dict[usrLoc.selected_loc][1], disabled=lat_long_input_disabled, on_change=update_events, args=(constellation,))
usrLoc.selected_position = (lat, lon)
usrLoc.update_timezone()

# 3. Get Date Range
currentDate = dt.now(timezone(usrLoc.selected_tz))
dateOptStart = dt(currentDate.year, currentDate.month, currentDate.day, currentDate.hour, 0, 0, 0, timezone(usrLoc.selected_tz))
dateChoice = st.sidebar.slider(
    f"Select time range ({usrLoc.selected_tz}):",
    min_value = dateOptStart,
    max_value = dateOptStart + timedelta(days=3),
    value=(dateOptStart, dateOptStart + timedelta(days=1, hours=12)),
    step = (timedelta(hours=6)),
    format = "MM/DD/YY HH:mm", on_change=update_events, args=(constellation,))
usrLoc.initialize_time_services(dateChoice)
if usrLoc.timerangeset:
    with st.spinner("Computing transit schedule..."):
        get_results(constellation) # display on main page
else:
    st.error('Please select a different time range!')

# 4. Display Map
st.sidebar.map(data=pd.DataFrame({'lat': usrLoc.selected_position[0], 'lon': usrLoc.selected_position[1]}, index=[0]), zoom=5, use_container_width=True)