diff --git a/packetraven/gui/base.py b/packetraven/gui/base.py
index 8d56b5e6..9b610229 100644
--- a/packetraven/gui/base.py
+++ b/packetraven/gui/base.py
@@ -57,6 +57,8 @@ def __init__(
             },
             'ssh_tunnel': {'ssh_hostname': None, 'ssh_username': None, 'ssh_password': None},
             'prediction': {
+                'prediction_start_time': None,
+                'prediction_start_location': None,
                 'prediction_ascent_rate': None,
                 'prediction_burst_altitude': None,
                 'prediction_sea_level_descent_rate': None,
diff --git a/packetraven/predicts.py b/packetraven/predicts.py
index 5a7686ec..99f541fb 100644
--- a/packetraven/predicts.py
+++ b/packetraven/predicts.py
@@ -1,7 +1,7 @@
 from abc import ABC, abstractmethod
 from datetime import datetime, timedelta
 from enum import Enum
-from typing import Any, Optional, Tuple, Union
+from typing import Any, Generator, Optional, Tuple, Union
 
 from dateutil.parser import parse as parse_date
 import numpy
@@ -13,9 +13,7 @@
 from packetraven.packets.tracks import LocationPacketTrack, PredictedTrajectory
 from packetraven.utilities import get_logger
 
-DEFAULT_ASCENT_RATE = 5.5
-DEFAULT_BURST_ALTITUDE = 28000
-DEFAULT_SEA_LEVEL_DESCENT_RATE = 9
+DEFAULT_FLOAT_ALTITUDE_UNCERTAINTY = 500
 UTC_TIMEZONE = pytz.utc
 
 LOGGER = get_logger('predicts')
@@ -375,7 +373,7 @@ def get_predictions(
     burst_altitude: float = None,
     sea_level_descent_rate: float = None,
     float_altitude: float = None,
-    float_altitude_uncertainty: float = 500,
+    float_altitude_uncertainty: float = None,
     float_duration: timedelta = None,
     api_url: str = None,
 ) -> [PredictedTrajectory]:
@@ -395,6 +393,8 @@ def get_predictions(
     """
 
     if start_location is not None:
+        if isinstance(start_location, Generator):
+            start_location = list(start_location)
         if len(start_location) == 2:
             start_location = (*start_location, 0)
 
@@ -404,6 +404,9 @@ def get_predictions(
     if float_duration is not None and float_altitude is None:
         float_altitude = burst_altitude
 
+    if float_altitude_uncertainty is None:
+        float_altitude_uncertainty = DEFAULT_FLOAT_ALTITUDE_UNCERTAINTY
+
     if api_url is None:
         api_url = PredictionAPIURL.cusf