in csst format, fits header emgain key word shoud be emset

csst_cpic_sim/io.py

@@ -445,7 +445,7 @@ def frame_header(obs_info, index, primary_header, camera_dict):
     header['CD2_2'] = np.cos(rotation)
 
     # Readout information
-    header['EMGAIN'] = float(obs_info['emgain'])
+    header['EMGAIN'] = float(obs_info['emset'])
     header['GAIN'] = float(camera_config['ph_per_adu'])
     header['DET_BIAS'] = float(camera_config['bias_level'])
     header['RON'] = float(camera_config['readout_noise'])
@@ -507,6 +507,7 @@ def save_fits_simple(images, obs_info, output_folder='./'):
     header['nframe'] = obs_info['nframe']
     header['band'] = obs_info['band']
     header['emgain'] = obs_info['emgain']
+    header['emset'] = obs_info['emset']
     header['obsid'] = obs_info['obsid']
     header['rotation'] = obs_info['rotation']
     shift = obs_info['shift']
@@ -542,8 +543,10 @@ def save_fits(images, obs_info, gnc_info, camera_dict={}, csst_format=True, outp
             - Exposure time of the each image.
         - nframe: int
             - Number of frames in the image.
-        - emgain: int
+        - emgain: float
             - EM gain of the camera.
+        - emset: int
+            -EM gain set value
         - obsid: str
             - Observation ID. Obsid must be 11 digits and start with 5 for CPIC. See pharse_obsid() for details.
         - rotation: float