diff --git a/csst_dfs_commons/models/constants.py b/csst_dfs_commons/models/constants.py
index 9d2ca23d17f267315465d0f7d073849da6af4e71..d1aa49da68402ec7ed0cb9f33762f6a90e834640 100644
--- a/csst_dfs_commons/models/constants.py
+++ b/csst_dfs_commons/models/constants.py
@@ -71,4 +71,6 @@ SLS_DECTECTORS2FILTER = {
     28: "GU",
     29: "GV",
     30: "GI"
-}
\ No newline at end of file
+}
+
+MSC_SCI_OBS_TYPE = 'SCI'
\ No newline at end of file
diff --git a/csst_dfs_commons/utils/fits.py b/csst_dfs_commons/utils/fits.py
index 649ab2b2a13e207d33408c60585a8ae462d754ee..7b6192819c8378c1ee1e16751858db27a6cafb6f 100644
--- a/csst_dfs_commons/utils/fits.py
+++ b/csst_dfs_commons/utils/fits.py
@@ -1,9 +1,11 @@
 from astropy_healpix import HEALPix
 from astropy.coordinates import ICRS
 from astropy import units as u
-from astropy.coordinates import SkyCoord
+from astropy.coordinates import SkyCoord, spherical_to_cartesian
 from astropy.io import fits
-
+from astropy import wcs
+import numpy as np
+import healpy as hp
 def get_header_value(key: str, headers, default_value = None):
     try:
         ret_value = None
@@ -31,4 +33,39 @@ def get_healpix_id(ra, dec, nside=32):
 def get_healpix_ids(ra, dec, radius, nside=32):
     hp = HEALPix(nside=nside, order='nested', frame=ICRS())
     coord = SkyCoord(ra = ra * u.deg, dec = dec * u.deg, frame='icrs')
-    return hp.cone_search_skycoord(coord, radius = radius * u.deg)    
\ No newline at end of file
+    return hp.cone_search_skycoord(coord, radius = radius * u.deg)
+
+def get_raw_header(filepath, **keys):
+    union = {}
+    with fits.open(filepath, **keys) as hdulist:
+        for hdu in hdulist:
+            for card in hdu.header.cards:
+                card.verify('fix')
+                key, value = card.keyword, card.value
+                if not key:
+                    continue
+                union[key]= value
+    return union
+
+def fits_of_healpix_ids(filepath, nside=256):
+    """ Get healpix ids for the fits file
+
+    :param filepath: the file path of fits
+    :param nside: default 128, approximate resolution at NSIDE 1024 is 0.057 deg, 12582912 bricks
+    :return: a numpy.ndarray (n,)
+    """    
+    with fits.open(filepath) as hdulist:
+        nx = get_header_value('NAXIS1', hdulist, 0)
+        ny = get_header_value('NAXIS2', hdulist, 0)
+
+        fits_wcs = wcs.WCS(hdulist[1])
+        ra0, dec0 = fits_wcs.all_pix2world(0, 0, 1)
+        ra0, dec1 = fits_wcs.all_pix2world(0, ny, 1)
+        ra1, dec0 = fits_wcs.all_pix2world(nx, 0, 1)
+        ra1, dec1 = fits_wcs.all_pix2world(nx, ny, 1)
+        ra_poly, dec_poly = np.array([[ra0, ra0, ra1, ra1], [dec0, dec1, dec0, dec1]])
+        xyzpoly = spherical_to_cartesian(np.deg2rad(ra_poly), np.deg2rad(dec_poly), 1)
+        xyzpoly = tuple(map(tuple, xyzpoly))
+        xyzpoly = np.array(xyzpoly).reshape(-1, 3)
+        healpixids = hp.query_polygon(nside, xyzpoly.T)
+        return healpixids
diff --git a/requirements.txt b/requirements.txt
index c69f7f633372454cccb4c42aa5af6bf5085c6381..d29e67e3530641aca31a947f892bfe6845476047 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
-astropy>=4.0
-astropy_healpix==0.7
\ No newline at end of file
+astropy
+astropy_healpix
+healpy
\ No newline at end of file