Add needed keywords to ALE ISD generation for SAR to support usgscsm (#353)

ale/formatters/usgscsm_formatter.py

@@ -44,9 +44,6 @@ def to_usgscsm(driver):
         'unit' : 'm'
     }
     
-    # shared isd keywords for Framer and Linescanner
-    if isinstance(driver, LineScanner) or isinstance(driver, Framer):
-        # exterior orientation for just Framer and LineScanner
     sun_positions, sun_velocities, _ = driver.sun_position
     isd_data['sun_position'] = {
         'positions' : sun_positions,
@@ -54,6 +51,9 @@ def to_usgscsm(driver):
         'unit' : 'm'
     }
 
+    # shared isd keywords for Framer and Linescanner
+    if isinstance(driver, LineScanner) or isinstance(driver, Framer):
+        # exterior orientation for just Framer and LineScanner
         frame_chain = driver.frame_chain
         sensor_to_target = frame_chain.compute_rotation(driver.sensor_frame_id, driver.target_frame_id)
         quaternions = sensor_to_target.quats
@@ -124,6 +124,8 @@ def to_usgscsm(driver):
         else:
             isd_data['dt_ephemeris'] = 0
 
+        isd_data['t0_ephemeris'] = interp_times[0]
+
     # line scan sensor model specifics
     if isinstance(driver, LineScanner):
         isd_data['name_model'] = 'USGS_ASTRO_LINE_SCANNER_SENSOR_MODEL'
@@ -153,7 +155,7 @@ def to_usgscsm(driver):
 
     # radar sensor model specifics
     if isinstance(driver, Radar):
-        isd_data['name_model'] = 'USGS_ASTRO_SAR_MODEL'
+        isd_data['name_model'] = 'USGS_ASTRO_SAR_SENSOR_MODEL'
         isd_data['starting_ephemeris_time'] = driver.ephemeris_start_time
         isd_data['ending_ephemeris_time'] = driver.ephemeris_stop_time
         isd_data['wavelength'] = driver.wavelength

tests/pytests/data/isds/lrominirf_isd.json

@@ -10105,7 +10105,25 @@
     ],
     "unit": "m"
   },
-  "name_model": "USGS_ASTRO_SAR_MODEL",
+ "sun_position": {
+    "positions": [
+      [
+        106362878979.21156,
+        106752639404.5255,
+        3800122792.5012856
+      ]
+    ],
+    "velocities": [
+      [
+        263427.2731009642,
+        -260832.3680061591,
+        -207.62866458328944
+      ]
+    ],
+    "unit": "m"
+  },
+  "name_model": "USGS_ASTRO_SAR_SENSOR_MODEL",
+  "t0_ephemeris": 325441417.4304223,
   "starting_ephemeris_time": 325441417.4304223,
   "ending_ephemeris_time": 325441721.22304827,
   "wavelength": 0.12596322416750805,