Update postings in STATIC layers granule ID to decimeters

python/packages/nisar/static/granule_id.py

@@ -1,27 +1,33 @@
 import string
 from datetime import datetime
+from osgeo import osr
 
 import isce3
 
 
-def int_to_3_digit_string(i: int) -> str:
+def int_to_n_digit_string(i: int, n: int = 3) -> str:
     """
-    Format an integer as a 3-digit zero-padded string.
+    Format an integer as an n-digit zero-padded string.
 
     Parameters
     ----------
     i : int
-        The input integer. Must be >= 0 and <= 999.
+        The input integer. Must be >= 0 and <= 10^n - 1.
+
+    n : int
+        The number of digits in the output string.
 
     Returns
     -------
     str
-        A 3-character string representation of the input integer, left-padded with
-        zeros.
+        An n-character string representation of the input integer, left-padded
+        with zeros.
     """
-    if (i < 0) or (i > 999):
-        raise ValueError(f"argument must be in the range [0, 999], got {i}")
-    return f"{i:03d}"
+    max_value = 10 ** n - 1
+    if (i < 0) or (i > max_value):
+        raise ValueError(f"argument must be in the range [0, {max_value}],"
+                         f" got {i}")
+    return f"{i:0{n}d}"
 
 
 def orbit_direction_to_char_code(direction: isce3.core.OrbitPassDirection) -> str:
@@ -99,6 +105,7 @@ def form_granule_id(
     frame_number: int,
     x_posting: float,
     y_posting: float,
+    epsg_code: int,
     validity_start_datetime: datetime,
     composite_release_id: str,
     processing_center: str,
@@ -129,6 +136,9 @@ def form_granule_id(
     x_posting, y_posting : float
         X and Y spacing of the raster coordinate grid, in the units of the grid's native
         coordinate system. Must be > 0 and <= 999.
+    epsg_code : int
+        EPSG code of the spatial reference system in which the raster coordinate grid is
+        defined.
     validity_start_datetime : datetime.datetime
         UTC date and time of the start of the granule's validity date range. Must not
         contain a fractional seconds component.
@@ -144,29 +154,56 @@ def form_granule_id(
     Returns
     -------
     str
-        The granule ID.
+        The granule ID. If the spatial reference system specified by
+        epsg_code is projected, the X and Y postings are multiplied
+        by 10 and formatted as four-digit, zero-padded integers.
+        If the spatial reference system is geographic, the X and Y
+        postings are formatted directly (without multiplication) as
+        four-digit, zero-padded integers, with the decimal point
+        removed.
 
     References
     ----------
     .. [1] S. Niemoeller, "NASA SDS Product Specification Level-2 Static Layers", JPL
         D-107727, 2025.
     """
-    template = string.Template(
-        "${MISSION}_${I}${L}_${PROD}_${REL}_${P}_${FRM}_${Xposting}_${Yposting}"
-        "_${ValidityStartDateTime}_${CRID}_${LOC}_${CTR}"
-    )
+    srs = osr.SpatialReference()
+    srs.ImportFromEPSG(epsg_code)
+
+    # The granule ID for projected coordinate systems encodes the X and Y
+    # postings in decimeters as 4-digit zero-padded integers,
+    # while the granule ID for geographic coordinate systems encodes the
+    # X and Y postings in degrees as 4-digit zero-padded integers with the
+    # decimal point removed.
+    if not srs.IsGeographic():
+        template = string.Template(
+            "${MISSION}_${I}${L}_${PROD}_${REL}_${P}_${FRM}"
+            "_${XpostingDecimeters}_${YpostingDecimeters}"
+            "_${ValidityStartDateTime}_${CRID}_${LOC}_${CTR}"
+        )
+    else:
+        template = string.Template(
+            "${MISSION}_${I}${L}_${PROD}_${REL}_${P}_${FRM}"
+            "_${Xposting}_${Yposting}"
+            "_${ValidityStartDateTime}_${CRID}_${LOC}_${CTR}"
+        )
     return template.substitute(
         MISSION=mission_id,
         I=radar_band,
         L=product_level,
         PROD=product_type,
-        REL=int_to_3_digit_string(relative_orbit_number),
+        REL=int_to_n_digit_string(relative_orbit_number, n=3),
         P=orbit_direction_to_char_code(orbit_pass_direction),
-        FRM=int_to_3_digit_string(frame_number),
-        Xposting=int_to_3_digit_string(int(round(x_posting))),
-        Yposting=int_to_3_digit_string(int(round(y_posting))),
-        ValidityStartDateTime=datetime_to_yyyymmddthhmmss(validity_start_datetime),
+        FRM=int_to_n_digit_string(frame_number, 3),
+        XpostingDecimeters=int_to_n_digit_string(int(10*round(x_posting)),
+                                                 n=4),
+        YpostingDecimeters=int_to_n_digit_string(int(10*round(y_posting)),
+                                                 n=4),
+        Xposting=int_to_n_digit_string(int(round(x_posting)), n=4),
+        Yposting=int_to_n_digit_string(int(round(y_posting)), n=4),
+        ValidityStartDateTime=datetime_to_yyyymmddthhmmss(
+            validity_start_datetime),
         CRID=composite_release_id,
         LOC=processing_center_to_char_code(processing_center),
-        CTR=int_to_3_digit_string(product_counter),
+        CTR=int_to_n_digit_string(product_counter, n=3),
     )

python/packages/nisar/workflows/static.py

@@ -236,6 +236,7 @@ def run_static_layers_workflow(config_file: os.PathLike | str) -> None:
             orbit_pass_direction=orbit_pass_direction,
             x_posting=abs(geo_grid.spacing_x),
             y_posting=abs(geo_grid.spacing_y),
+            epsg_code=geo_grid_params["epsg"],
             validity_start_datetime=validity_start_datetime,
             composite_release_id=primary_executable_params["composite_release_id"],
             processing_center=primary_executable_params["processing_center"],

tests/python/packages/nisar/static/granule_id.py

@@ -14,13 +14,14 @@ def test_form_granule_id():
         frame_number=2,
         x_posting=10.0,
         y_posting=5.0,
+        epsg_code=32611,
         validity_start_datetime=datetime.fromisoformat("1999-12-31T23:59:59"),
         composite_release_id="T01023",
         processing_center="JPL",
         product_counter=1,
     )
     assert (
-        granule_id == "NISAR_L2_STATIC_001_A_002_010_005_19991231T235959_T01023_J_001"
+        granule_id == "NISAR_L2_STATIC_001_A_002_0100_0050_19991231T235959_T01023_J_001"
     )
 
     granule_id = form_granule_id(
@@ -33,11 +34,12 @@ def test_form_granule_id():
         frame_number=124,
         x_posting=80.0,
         y_posting=80.0,
+        epsg_code=32611,
         validity_start_datetime=datetime.fromisoformat("2000-01-01T00:00:00"),
         composite_release_id="A11111",
         processing_center="somewhere else",
         product_counter=999,
     )
     assert (
-        granule_id == "NISAR_S2_STATIC_123_D_124_080_080_20000101T000000_A11111_X_999"
+        granule_id == "NISAR_S2_STATIC_123_D_124_0800_0800_20000101T000000_A11111_X_999"
     )