Unit conversions

sarxarray/_io.py

@@ -15,6 +15,8 @@
     META_ARRAY_KEYS,
     META_FLOAT_KEYS,
     META_INT_KEYS,
+    META_UNIT_CONVERSION_MULTIPLICATION_KEYS_DORIS4,
+    META_UNIT_CONVERSION_MULTIPLICATION_KEYS_DORIS5,
     RE_PATTERNS_DORIS4,
     RE_PATTERNS_DORIS5,
     RE_PATTERNS_DORIS5_IFG,
@@ -441,8 +443,16 @@
     # Convert time metadata from string to datetime
     if driver == "doris5":
         time_format = TIME_FORMAT_DORIS5
+        unit_conversions = META_UNIT_CONVERSION_MULTIPLICATION_KEYS_DORIS5
     elif driver == "doris4":
         time_format = TIME_FORMAT_DORIS4
+        unit_conversions = META_UNIT_CONVERSION_MULTIPLICATION_KEYS_DORIS4
+    else:
+        raise NotImplementedError(
+            f"Driver '{driver}' is not implemented. "
+            "Supported drivers are: 'doris4', 'doris5'."
+        )
+
     list_time = []
     # If the time is a single string, convert it to a list
     if isinstance(metadata[TIME_STAMP_KEY], str):
@@ -473,6 +483,8 @@
                 for row in range(len(arr)):
                     for col in range(len(arr[row])):
                         regulated_array[row, col] = META_ARRAY_KEYS[key](arr[row][col])
+                if key in unit_conversions.keys():
+                    regulated_array *= unit_conversions[key]
                 regulated_arrays.append(np.copy(regulated_array))
 
             metadata[key] = [
@@ -481,7 +493,6 @@
             if len(metadata[key]) == 1:
                 metadata[key] = metadata[key][0]
 
-
         else:
             # Only keep the unique values
             if isinstance(metadata[key], list):
@@ -502,12 +513,20 @@
                         f"Inconsistency found in metadata key:  {key}. "
                         "Standard deviation is larger than 1% of the mean."
                     )
+                if key in unit_conversions.keys():
+                    metadata[key] *= unit_conversions[key]
             if key in META_INT_KEYS:
                 if isinstance(metadata[key], str):
                     metadata[key] = int(metadata[key])
+                    if key in unit_conversions.keys():
+                        metadata[key] *= unit_conversions[key]
                 elif len(metadata[key]) > 1:  # set with multiple values
-                    metadata[key] = set([int(v) for v in metadata[key]])
-
+                    if key in unit_conversions.keys():
+                        metadata[key] = set(
+                            [int(v) * unit_conversions[key] for v in metadata[key]]
+                        )
+                    else:
+                        metadata[key] = set([int(v) for v in metadata[key]])
             if key in ["number_of_lines", "number_of_pixels"]:
                 if isinstance(metadata[key], set):
                     warning_msg = f"Multiple values found in {key}: {metadata[key]}."

sarxarray/conf.py

@@ -26,7 +26,7 @@
     "weighting_range": r"Weighting_range:\s+(.+)",
     "first_azimuth_time": r"First_pixel_azimuth_time \(UTC\):\s+(.+)",
 }
-# Regular expressions for reading metadata from DORIS4 files
+# Regular expressions for reading metadata from DORIS5 files
 RE_PATTERNS_DORIS5 = {
     "sar_processor": r"SAR_PROCESSOR:\s+(.+)",
     "product_type": r"Product type specifier:\s+(.+)",
@@ -107,6 +107,19 @@
 META_ARRAY_KEYS = {
     "orbit_txyz": float  # DORIS5 only
 }
+# Some keys are not read in in SI units. The following dictionary specifies those
+# keys, and the factor they should be multiplied by to restore them to SI units
+META_UNIT_CONVERSION_MULTIPLICATION_KEYS_DORIS4 = {
+    "range_sampling_rate": 1_000_000,  # originally MHz
+    "total_range_bandwidth": 1_000_000,  # originally MHz
+    "first_range_time": 0.001,  # originally ms
+}
+
+META_UNIT_CONVERSION_MULTIPLICATION_KEYS_DORIS5 = {
+    "range_sampling_rate": 1_000_000,  # originally MHz
+    "total_range_bandwidth": 1_000_000,  # originally MHz
+    "first_range_time": 0.001,  # originally ms
+}
 # Time formats for DORIS metadata
 TIME_FORMAT_DORIS4 = "%d-%b-%Y %H:%M:%S.%f"
 TIME_FORMAT_DORIS5 = "%Y-%b-%d %H:%M:%S.%f"