diff --git a/swmmanywhere/geospatial_operations.py b/swmmanywhere/geospatial_operations.py
index 8576e41b..6749f4c7 100644
--- a/swmmanywhere/geospatial_operations.py
+++ b/swmmanywhere/geospatial_operations.py
@@ -1,6 +1,9 @@
 # -*- coding: utf-8 -*-
 """Created 2024-01-20.
 
+A module containing functions to perform a variety of geospatial operations,
+such as reprojecting coordinates and handling raster data.
+
 @author: Barnaby Dobson
 """
 from functools import lru_cache
@@ -21,7 +24,7 @@
 TransformerFromCRS = lru_cache(pyproj.transformer.Transformer.from_crs)
 
 
-def get_utm_crs(x: float, 
+def get_utm_epsg(x: float, 
                 y: float, 
                 crs: str | int | pyproj.CRS = 'EPSG:4326', 
                 datum_name: str = "WGS 84"):
@@ -141,7 +144,7 @@ def interpolate_points_on_raster(x: list[float],
                                         bounds_error=False, 
                                         fill_value=None)
         # Interpolate for x,y
-        return [interp_wrap((y_, x_), interp, grid, values) for x_, y_ in zip(x,y)]
+        return [interp_with_nans((y_, x_), interp, grid, values) for x_, y_ in zip(x,y)]
     
 def reproject_raster(target_crs: str, 
                      fid: str, 
diff --git a/tests/test_geospatial.py b/tests/test_geospatial.py
index cf320c62..fd70f724 100644
--- a/tests/test_geospatial.py
+++ b/tests/test_geospatial.py
@@ -16,8 +16,8 @@
 from swmmanywhere import geospatial_operations as go
 
 
-def test_interp_wrap():
-    """Test the interp_wrap function."""
+def test_interp_with_nans():
+    """Test the interp_interp_with_nans function."""
     # Define a simple grid and values
     x = np.linspace(0, 1, 5)
     y = np.linspace(0, 1, 5)
@@ -32,13 +32,13 @@ def test_interp_wrap():
 
     # Test the function at a point inside the grid
     yx = (0.875, 0.875)
-    result = go.interp_wrap(yx, interp, grid, values)
+    result = go.interp_with_nans(yx, interp, grid, values)
     assert result == 0.875
 
     # Test the function on a nan point
     values_grid[1][1] = np.nan
     yx = (0.251, 0.25) 
-    result = go.interp_wrap(yx, interp, grid, values)
+    result = go.interp_with_nans(yx, interp, grid, values)
     assert result == values_grid[1][2]
 
 @patch('rasterio.open')
@@ -70,11 +70,11 @@ def test_interpolate_points_on_raster(mock_rst_open):
 def test_get_utm():
     """Test the get_utm_epsg function."""
     # Test a northern hemisphere point
-    crs = go.get_utm_epsg(-1, 51)
+    crs = go.get_utm_epsg(-1.0, 51.0)
     assert crs == 'EPSG:32630'
 
     # Test a southern hemisphere point
-    crs = go.get_utm_epsg(-1, -51)
+    crs = go.get_utm_epsg(-1.0, -51.0)
     assert crs == 'EPSG:32730'
 
 def create_raster(fid):