Mgs time bias (#538)

* Updated disclaimer for release

* Handle MGS time bias for NAC and WAC

* Re-enabled MGS drivers

* Updated changelog

CHANGELOG.md

@@ -35,6 +35,10 @@ release.
 
 ## [Unreleased]
 
+### Fixed
+- MexHrscIsisLabelNaifSpice and MexHrscPds3NaifSpice have had there ephemeris times changed and sampling factor updated. MexHrscIsisLabelNaifSpice has also had it's focal length, and focal plane translation updated to reflect those found in the MexHrscPds3NaifSpice driver [#541](https://github.com/DOI-USGS/ale/pull/541)
+- MGS drivers now account for a time bias in the ephemeris data [#538](https://github.com/DOI-USGS/ale/pull/538)
+
 ## [0.9.0] - 2023-04-19
 
 ### Fixed

ale/base/base.py

@@ -359,7 +359,6 @@ class Driver():
               self._projection = "" 
         return self._projection
     
-
     @property 
     def geotransform(self):
         if not hasattr(self, "_geotransform"): 

ale/base/data_naif.py

@@ -428,7 +428,8 @@ class NaifSpice():
                                                       target_frame=self.target_frame_id,
                                                       center_ephemeris_time=self.center_ephemeris_time,
                                                       ephemeris_times=self.ephemeris_time,
-                                                      nadir=nadir, exact_ck_times=exact_ck_times)
+                                                      nadir=nadir, exact_ck_times=exact_ck_times,
+                                                      inst_time_bias=self.instrument_time_bias)
 
             if nadir:
                 # Logic for nadir calculation was taken from ISIS3
@@ -589,3 +590,17 @@ class NaifSpice():
                 pass
 
         return self._naif_keywords
+
+    @property
+    def instrument_time_bias(self):
+        """
+        Time bias used for generating sensor orientations
+
+        The default is 0 for not time bias
+
+        Returns
+        -------
+        : int
+          Time bias in ephemeris time
+        """
+        return 0
\ No newline at end of file

ale/drivers/mgs_drivers.py

@@ -130,6 +130,20 @@ class MgsMocNarrowAngleCameraIsisLabelNaifSpiceDriver(LineScanner, IsisLabel, Na
         """
         return [0, 0.0131240578522949, 0.0131240578522949]
 
+    @property
+    def instrument_time_bias(self):
+      """
+      Defines the time bias for Mars Global Survayor instrument rotation information.
+
+      This shifts the sensor orientation window back by 1.15 seconds in ephemeris time.
+
+      Returns
+      -------
+      : int
+        Time bias adjustment
+      """
+      return -1.15
+
 class MgsMocWideAngleCameraIsisLabelNaifSpiceDriver(LineScanner, IsisLabel, NaifSpice, RadialDistortion, Driver):
     """
     Driver for reading MGS MOC WA ISIS labels.
@@ -268,3 +282,17 @@ class MgsMocWideAngleCameraIsisLabelNaifSpiceDriver(LineScanner, IsisLabel, Naif
             return [0, -.007, .007]
         else:
             return [0, .007, .007]
+
+    @property
+    def instrument_time_bias(self):
+      """
+      Defines the time bias for Mars Global Survayor instrument rotation information.
+
+      This shifts the sensor orientation window back by 1.15 seconds in ephemeris time.
+
+      Returns
+      -------
+      : int
+        Time bias adjustment
+      """
+      return -1.15

ale/transformation.py

@@ -96,7 +96,7 @@ class FrameChain(nx.DiGraph):
                      of frame rotations in the frame chain
     """
     @classmethod
-    def from_spice(cls, sensor_frame, target_frame, center_ephemeris_time, ephemeris_times=[], nadir=False, exact_ck_times=False):
+    def from_spice(cls, sensor_frame, target_frame, center_ephemeris_time, ephemeris_times=[], nadir=False, exact_ck_times=False, inst_time_bias=0):
         frame_chain = cls()
         sensor_times = []
         # Default assume one time
@@ -106,7 +106,7 @@ class FrameChain(nx.DiGraph):
 
         if exact_ck_times and len(ephemeris_times) > 1 and not nadir:
             try:
-                sensor_times = cls.extract_exact_ck_times(ephemeris_times[0], ephemeris_times[-1], sensor_frame)
+                sensor_times = cls.extract_exact_ck_times(ephemeris_times[0] + inst_time_bias, ephemeris_times[-1] + inst_time_bias, sensor_frame)
             except Exception as e:
                 pass
 
@@ -123,8 +123,8 @@ class FrameChain(nx.DiGraph):
 
         constant_frames.extend(target_constant_frames)
 
-        frame_chain.compute_time_dependent_rotiations(sensor_time_dependent_frames, sensor_times)
-        frame_chain.compute_time_dependent_rotiations(target_time_dependent_frames, target_times)
+        frame_chain.compute_time_dependent_rotiations(sensor_time_dependent_frames, sensor_times, inst_time_bias)
+        frame_chain.compute_time_dependent_rotiations(target_time_dependent_frames, target_times, 0)
 
         for s, d in constant_frames:
             quats = np.zeros(4)
@@ -380,7 +380,7 @@ class FrameChain(nx.DiGraph):
 
         return times
 
-    def compute_time_dependent_rotiations(self, frames, times):
+    def compute_time_dependent_rotiations(self, frames, times, time_bias):
         """
         Computes the time dependent rotations based on a list of tuples that define the
         relationships between frames as (source, destination) and a list of times to
@@ -409,5 +409,6 @@ class FrameChain(nx.DiGraph):
 
             if not avs:
                 avs = None
-            rotation = TimeDependentRotation(quats, times, s, d, av=avs)
+            biased_times = [time - time_bias for time in times]
+            rotation = TimeDependentRotation(quats, biased_times, s, d, av=avs)
             self.add_edge(rotation=rotation)
\ No newline at end of file

tests/pytests/data/isds/mgsmocwa_isd.json

@@ -70,90 +70,97 @@
       -94000,
       1
     ],
-    "ck_table_start_time": -69382819.71598774,
-    "ck_table_end_time": -69382511.7160111,
-    "ck_table_original_size": 78,
+    "ck_table_start_time": -69382822.56598744,
+    "ck_table_end_time": -69382510.5660111,
+    "ck_table_original_size": 79,
     "ephemeris_times": [
-      -69382819.71598774,
-      -69382815.71598805,
-      -69382811.71598835,
-      -69382807.71598867,
-      -69382803.71598896,
-      -69382799.71598926,
-      -69382795.71598957,
-      -69382791.71598987,
-      -69382787.71599017,
-      -69382783.71599048,
-      -69382779.71599078,
-      -69382775.7159911,
-      -69382771.7159914,
-      -69382767.71599169,
-      -69382763.715992,
-      -69382759.7159923,
-      -69382755.7159926,
-      -69382751.71599291,
-      -69382747.71599321,
-      -69382743.71599352,
-      -69382739.71599382,
-      -69382735.71599412,
-      -69382731.71599443,
-      -69382727.71599473,
-      -69382723.71599503,
-      -69382719.71599534,
-      -69382715.71599564,
-      -69382711.71599595,
-      -69382707.71599625,
-      -69382703.71599655,
-      -69382699.71599686,
-      -69382695.71599716,
-      -69382691.71599746,
-      -69382687.71599777,
-      -69382683.71599805,
-      -69382679.71599837,
-      -69382675.71599866,
-      -69382671.71599896,
-      -69382667.71599928,
-      -69382663.71599957,
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-      -69382655.71600018,
-      -69382651.71600048,
-      -69382647.71600078,
-      -69382643.7160011,
-      -69382639.71600139,
-      -69382635.7160017,
-      -69382631.716002,
-      -69382627.7160023,
-      -69382623.71600261,
-      -69382619.71600291,
-      -69382615.71600321,
-      -69382611.71600352,
-      -69382607.71600382,
-      -69382603.71600413,
-      -69382599.71600443,
-      -69382595.71600473,
-      -69382591.71600504,
-      -69382587.71600534,
-      -69382583.71600564,
-      -69382579.71600595,
-      -69382575.71600625,
-      -69382571.71600656,
-      -69382567.71600686,
-      -69382563.71600716,
-      -69382559.71600747,
-      -69382555.71600777,
-      -69382551.71600807,
-      -69382547.71600838,
-      -69382543.71600868,
-      -69382539.71600899,
-      -69382535.71600929,
-      -69382531.71600959,
-      -69382527.7160099,
-      -69382523.7160102,
-      -69382519.7160105,
-      -69382515.71601081,
-      -69382511.7160111
+      -69382822.56598744,
+      -69382818.56598774,
+      -69382814.56598805,
+      -69382810.56598835,
+      -69382806.56598866,
+      -69382802.56598896,
+      -69382798.56598926,
+      -69382794.56598957,
+      -69382790.56598987,
+      -69382786.56599016,
+      -69382782.56599048,
+      -69382778.56599078,
+      -69382774.56599109,
+      -69382770.56599139,
+      -69382766.56599168,
+      -69382762.565992,
+      -69382758.5659923,
+      -69382754.5659926,
+      -69382750.5659929,
+      -69382746.5659932,
+      -69382742.56599352,
+      -69382738.56599382,
+      -69382734.56599411,
+      -69382730.56599443,
+      -69382726.56599472,
+      -69382722.56599502,
+      -69382718.56599534,
+      -69382714.56599563,
+      -69382710.56599595,
+      -69382706.56599624,
+      -69382702.56599654,
+      -69382698.56599686,
+      -69382694.56599715,
+      -69382690.56599745,
+      -69382686.56599776,
+      -69382682.56599805,
+      -69382678.56599836,
+      -69382674.56599866,
+      -69382670.56599896,
+      -69382666.56599927,
+      -69382662.56599957,
+      -69382658.56599987,
+      -69382654.56600018,
+      -69382650.56600048,
+      -69382646.56600077,
+      -69382642.56600109,
+      -69382638.56600139,
+      -69382634.5660017,
+      -69382630.566002,
+      -69382626.5660023,
+      -69382622.5660026,
+      -69382618.5660029,
+      -69382614.5660032,
+      -69382610.56600352,
+      -69382606.56600381,
+      -69382602.56600413,
+      -69382598.56600443,
+      -69382594.56600472,
+      -69382590.56600504,
+      -69382586.56600533,
+      -69382582.56600563,
+      -69382578.56600595,
+      -69382574.56600624,
+      -69382570.56600656,
+      -69382566.56600685,
+      -69382562.56600715,
+      -69382558.56600747,
+      -69382554.56600776,
+      -69382550.56600806,
+      -69382546.56600837,
+      -69382542.56600867,
+      -69382538.56600899,
+      -69382534.56600928,
+      -69382530.56600958,
+      -69382526.5660099,
+      -69382522.56601019,
+      -69382518.56601049,
+      -69382514.5660108,
+      -69382510.5660111
     ],
     "quaternions": [
+      [
+        -0.23708037152577427,
+        0.06913949189951372,
+        0.9353535261221577,
+        0.2532319278209684
+      ],
       [
         -0.23957495682735272,
         0.06980832265124022,
@@ -624,6 +631,11 @@
       ]
     ],
     "angular_velocities": [
+      [
+        -1.3243650720946794e-05,
+        -0.001147942524828248,
+        -0.0006765182794334033
+      ],
       [
         -1.4192050960089805e-05,
         -0.001149540028905371,

tests/pytests/test_cassini_drivers.py

@@ -140,7 +140,7 @@ class test_cassini_pds3_naif(unittest.TestCase):
             target_frame_id.return_value = -800
             frame_chain = self.driver.frame_chain
             assert len(frame_chain.nodes()) == 0
-            from_spice.assert_called_with(center_ephemeris_time=2.4, ephemeris_times=[2.4], nadir=False, sensor_frame=14082360, target_frame=-800, exact_ck_times=True)
+            from_spice.assert_called_with(center_ephemeris_time=2.4, ephemeris_times=[2.4], nadir=False, sensor_frame=14082360, target_frame=-800, exact_ck_times=True,  inst_time_bias=0)
 
 # ========= Test cassini isislabel and naifspice driver =========
 class test_cassini_isis_naif(unittest.TestCase):
@@ -212,4 +212,4 @@ class test_cassini_isis_naif(unittest.TestCase):
             target_frame_id.return_value = -800
             frame_chain = self.driver.frame_chain
             assert len(frame_chain.nodes()) == 0
-            from_spice.assert_called_with(center_ephemeris_time=2.4000000000000004, ephemeris_times=[2.4000000000000004], nadir=False, sensor_frame=14082360, target_frame=-800, exact_ck_times=True)
+            from_spice.assert_called_with(center_ephemeris_time=2.4000000000000004, ephemeris_times=[2.4000000000000004], nadir=False, sensor_frame=14082360, target_frame=-800, exact_ck_times=True, inst_time_bias=0)

tests/pytests/test_mgs_drivers.py

@@ -44,7 +44,6 @@ def test_wac_load(test_wac_kernels):
 
     isd_str = ale.loads(label_file, props={'kernels': test_wac_kernels})
     isd_obj = json.loads(isd_str)
-    print(json.dumps(isd_obj, indent=2))
     assert compare_dicts(isd_obj, compare_dict) == []