Merge pull request #18 from LCOGT/feature/wcs-line-analysis

wcs solution for coords and length of line analysis, dev warning for auth token

datalab/datalab_session/analysis/line_profile.py

@@ -1,4 +1,6 @@
 from skimage.measure import profile_line
+from astropy.wcs import WCS
+from astropy.wcs import WcsError
 
 from datalab.datalab_session.util import scale_points
 from datalab.datalab_session.util import get_hdu
@@ -9,9 +11,31 @@ def line_profile(input: dict):
     Creates an array of luminosity values and the length of the line in arcseconds
   """
   sci_hdu = get_hdu(input['basename'], 'SCI')
-
+  
   x_points, y_points = scale_points(input["height"], input["width"], sci_hdu.data.shape[0], sci_hdu.data.shape[1], x_points=[input["x1"], input["x2"]], y_points=[input["y1"], input["y2"]])
+
+  # Line profile and distance in arcseconds
   line_profile = profile_line(sci_hdu.data, (x_points[0], y_points[0]), (x_points[1], y_points[1]), mode="constant", cval=-1)
-  arcsec = len(line_profile) * sci_hdu.header["PIXSCALE"]
+
+
+  # Calculations for coordinates and angular distance
+  try: 
+    wcs = WCS(sci_hdu.header)
+
+    start_sky_coord = wcs.pixel_to_world(x_points[0], y_points[0])
+    end_sky_coord = wcs.pixel_to_world(x_points[1], y_points[1])
+
+    arcsec_angle = start_sky_coord.separation(end_sky_coord).arcsecond
+
+    start_coords = [start_sky_coord.ra.deg, start_sky_coord.dec.deg]
+    end_coords = [end_sky_coord.ra.deg, end_sky_coord.dec.deg]
+
+  except WcsError as e:
+    error = f'{input["basename"]} does not have a valid WCS header'
+    print(error, e)
+    # if theres no valid WCS solution then we default to using pixscale to calculate the angle, and no coordinates
+    start_coords = None
+    end_coords = None
+    arcsec_angle = len(line_profile) * sci_hdu.header["PIXSCALE"]
 
-  return {"line_profile": line_profile, "arcsec": arcsec}
+  return {"line_profile": line_profile, "arcsec": arcsec_angle, "start_coords": start_coords, "end_coords": end_coords}

datalab/settings.py

@@ -137,6 +137,9 @@ def get_list_from_env(variable, default=None):
 # Datalab Archive
 ARCHIVE_API = os.getenv('ARCHIVE_API', 'https://archive-api.lco.global')
 ARCHIVE_API_TOKEN = os.getenv('ARCHIVE_API_TOKEN')
+if not ARCHIVE_API_TOKEN:
+    print("WARNING: ARCHIVE_API_TOKEN is missing from the environment.")
+    exit()
 
 # Database
 # https://docs.djangoproject.com/en/4.2/ref/settings/#databases