sort needed dates, pull prev/next day for sp3,clk if close to day boundary

Author: betaBison

gnss_lib_py/utils/ephemeris_downloader.py

@@ -256,6 +256,10 @@ def _extract_ephemeris_dates(file_type, dt_timestamps):
     will also be included. If after 22:00, the next day will also be
     included.
 
+    To appropriately compute fit satellite position and clock esimates,
+    sp3 and clk files are also pulled for the previous or next day if
+    the timestamps are close to the start or end of the day.
+
     Parameters
     ----------
     file_type : string
@@ -265,9 +269,9 @@ def _extract_ephemeris_dates(file_type, dt_timestamps):
 
     Returns
     -------
-    needed_dates : set
-        Set of datetime.date objects of the days in UTC for which
-        ephemeris needs to be retrieved.
+    needed_dates : List
+        List of datetime.date objects of the days in UTC for which
+        ephemeris needs to be retrieved in order sorted by date.
 
     """
 
@@ -276,7 +280,7 @@ def _extract_ephemeris_dates(file_type, dt_timestamps):
 
     needed_dates = set()
 
-    if file_type == "rinex_nav":
+    if file_type in ("rinex_nav","sp3","clk"):
         # add every day for each timestamp
         needed_dates.update({dt.date() for dt in dt_timestamps})
 
@@ -293,13 +297,11 @@ def _extract_ephemeris_dates(file_type, dt_timestamps):
                              (dt.date() != datetime.utcnow().date()))
                         })
 
-    elif file_type in ("sp3","clk"):
-        # add every day for each timestamp
-        needed_dates.update({dt.date() for dt in dt_timestamps})
-
     else:
         raise RuntimeError("invalid file_type variable option")
 
+    needed_dates = sorted(list(needed_dates))
+
     return needed_dates
 
 def _valid_ephemeris_in_paths(date, possible_types, file_paths=None):

tests/utils/test_ephemeris_downloader.py

@@ -275,48 +275,55 @@ def test_extract_ephemeris_dates():
     # check basic case
     noon_utc = datetime(2023, 7, 27, 12, 0, 0, 0, tzinfo=timezone.utc)
     dates = ed._extract_ephemeris_dates("rinex_nav", np.array([noon_utc]))
-    assert dates == {datetime(2023, 7, 27).date()}
+    assert dates == [datetime(2023, 7, 27).date()]
 
     # check that timezone conversion is happening
     eleven_pt = datetime(2023, 7, 26, 23, 0, 0, 0,
                     tzinfo=timezone(-timedelta(hours=8)))
     dates = ed._extract_ephemeris_dates("rinex_nav", np.array([eleven_pt]))
-    assert dates == {datetime(2023, 7, 27).date()}
+    assert dates == [datetime(2023, 7, 27).date()]
 
     # check add prev day if after before 2am
     for hour in [0,1,2]:
         two_am_utc = datetime(2023, 7, 27, hour, 0, 0, 0, tzinfo=timezone.utc)
         dates = ed._extract_ephemeris_dates("rinex_nav", np.array([two_am_utc]))
-        assert dates == {datetime(2023, 7, 26).date(),
-                         datetime(2023, 7, 27).date()}
+        assert dates == [datetime(2023, 7, 26).date(),
+                         datetime(2023, 7, 27).date()]
 
     # check add next day if after 10pm
     for hour in [22,23]:
         ten_pm_utc = datetime(2023, 7, 26, hour, 0, 0, 0, tzinfo=timezone.utc)
         dates = ed._extract_ephemeris_dates("rinex_nav", np.array([ten_pm_utc]))
-        assert dates == {datetime(2023, 7, 26).date(),
-                         datetime(2023, 7, 27).date()}
+        assert dates == [datetime(2023, 7, 26).date(),
+                         datetime(2023, 7, 27).date()]
 
     # check don't add next day if after 10pm on current day
     ten_pm_utc_today = datetime.combine(datetime.utcnow().date(),
                                         time(22,tzinfo=timezone.utc))
     dates = ed._extract_ephemeris_dates("rinex_nav", np.array([ten_pm_utc_today]))
-    assert dates == {datetime.utcnow().date()}
+    assert dates == [datetime.utcnow().date()]
 
     # check that across multiple days there aren't duplicates
     dates = ed._extract_ephemeris_dates("rinex_nav", np.array([noon_utc,
                                                           eleven_pt,
                                                           two_am_utc,
                                                           ten_pm_utc]))
-    assert dates == {datetime(2023, 7, 26).date(),
-                     datetime(2023, 7, 27).date()}
+    assert dates == [datetime(2023, 7, 26).date(),
+                     datetime(2023, 7, 27).date()]
+
+    # test order is maintained in sorted order
+    dates = ed._extract_ephemeris_dates("rinex_nav", np.array([noon_utc + timedelta(days=1),
+                                                               noon_utc,
+                                                               ]))
+    assert dates == [datetime(2023, 7, 27).date(),
+                     datetime(2023, 7, 28).date()]
 
     # check for two separate days
     noon_utc_01 = datetime(2023, 7, 1, 12, 0, 0, 0, tzinfo=timezone.utc)
     dates = ed._extract_ephemeris_dates("rinex_nav", np.array([noon_utc,
                                                            noon_utc_01]))
-    assert dates == {datetime(2023, 7, 27).date(),
-                     datetime(2023, 7, 1).date()}
+    assert dates == [datetime(2023, 7, 1).date(),
+                     datetime(2023, 7, 27).date()]
 
 def test_ftp_errors(ephem_download_path):
     """Test FTP download errors.