diff --git a/pytomoatt/checkerboard.py b/pytomoatt/checkerboard.py
index 589c577..a65db5c 100644
--- a/pytomoatt/checkerboard.py
+++ b/pytomoatt/checkerboard.py
@@ -22,7 +22,10 @@ def __init__(self, model_fname:str, para_fname='input_params.yml') -> None:
             self.vel = f['vel'][:]
             self.eta = f['eta'][:]
             self.xi = f['xi'][:]
-            self.zeta = f['zeta'][:]
+            if 'zeta' in f:  # some model may not have zeta
+                self.zeta = f['zeta'][:]
+            else:
+                self.zeta = np.zeros_like(self.vel)
         self._init_axis()
 
     def _init_axis(self):
diff --git a/pytomoatt/io/crustmodel.py b/pytomoatt/io/crustmodel.py
index f7fa937..15bdc66 100644
--- a/pytomoatt/io/crustmodel.py
+++ b/pytomoatt/io/crustmodel.py
@@ -2,6 +2,7 @@
 from os.path import dirname, abspath, join
 from ..utils.common import init_axis
 from ..setuplog import SetupLog
+from ..utils.rotate import rtp_rotation_reverse
 import pickle
 import sys
 from tqdm import tqdm
@@ -40,7 +41,7 @@ def __init__(self, fname=join(dirname(dirname(abspath(__file__))), 'data', 'crus
             self.points_dict = pickle.load(f)
         self.log = SetupLog()
 
-    def griddata(self, min_max_dep, min_max_lat, min_max_lon, n_rtp, type='vp'):
+    def griddata(self, min_max_dep, min_max_lat, min_max_lon, n_rtp, type='vp', rotate=None):
         """Linearly interpolate velocity into regular grids
 
         :param min_max_dep: min and max depth, ``[min_dep, max_dep]``
@@ -63,25 +64,40 @@ def griddata(self, min_max_dep, min_max_lat, min_max_lon, n_rtp, type='vp'):
         else:
             self.log.Modellog.error(f"Velocity type {type} not supported in CRUST1.0 model")
             sys.exit(1)
+
         self.dd, self.tt, self.pp, _, _, _, = init_axis(
             min_max_dep, min_max_lat, min_max_lon, n_rtp
         )
 
+        tt_2d, pp_2d = np.meshgrid(self.tt, self.pp, indexing='ij')
+
+        # rotate reversely, from computational grid to physical grid
+        if rotate is not None:
+            try:
+                central_lat, central_lon, rotation_angle = rotate
+            except (TypeError, ValueError):
+                self.log.Modellog.error("rotate must be a 3-item sequence: [central_lat, central_lon, rotation_angle]")
+                sys.exit(1)
+            tt_2d, pp_2d = rtp_rotation_reverse(tt_2d, pp_2d, central_lat, central_lon, rotation_angle)
+
         # Grid data 
         self.log.Modellog.info('Grid data, please wait for a few minutes')
         vel = np.zeros(n_rtp)
         with tqdm(total=self.n_rtp[1] * self.n_rtp[2], desc='Gridding') as pbar:
             for ilat in range(self.n_rtp[1]):
-                new_lat = self.tt[ilat]
-                idx_lat_left, ratio_lat = degree_to_idx_and_ratio(new_lat)
-                idx_lat_right = idx_lat_left + 1
-                if idx_lat_left == -1:
-                    idx_lat_left = 0
-                    idx_lat_right = 1
-
                 for ilon in range(self.n_rtp[2]):
                     pbar.update(1)
-                    new_lon = self.pp[ilon]
+                    
+                    # latitude index and ratio
+                    new_lat = tt_2d[ilat, ilon]
+                    idx_lat_left, ratio_lat = degree_to_idx_and_ratio(new_lat)
+                    idx_lat_right = idx_lat_left + 1
+                    if idx_lat_left == -1:
+                        idx_lat_left = 0
+                        idx_lat_right = 1
+                    
+                    # longitude index and ratio
+                    new_lon = pp_2d[ilat, ilon]
                     idx_lon_left, ratio_lon = degree_to_idx_and_ratio(new_lon)
                     idx_lon_right = idx_lon_left + 1
                     if idx_lon_left == -1:  # between -179.5 and +179.5
diff --git a/pytomoatt/model.py b/pytomoatt/model.py
index 14c5102..ef1adc8 100644
--- a/pytomoatt/model.py
+++ b/pytomoatt/model.py
@@ -102,18 +102,20 @@ def to_xarray(self):
         )
         return dataset
 
-    def grid_data_crust1(self, type='vp'):
+    def grid_data_crust1(self, type='vp', rotate=None):
         """Grid data from CRUST1.0 model
 
         :param type: Specify velocity type of ``vp`` or ``vs``, defaults to 'vp'
         :type type: str, optional
+        :param rotate: Rotation parameters [central_lat, central_lon, rotation_angle] in degrees, defaults to None
         """
         cm = CrustModel()
         self.vel = cm.griddata(
             self.min_max_dep,
             self.min_max_lat,
             self.min_max_lon, 
-            self.n_rtp, type=type
+            self.n_rtp, type=type,
+            rotate=rotate
         )
         
     def grid_data_ascii(self, model_fname:str, **kwargs):