diff --git a/README.md b/README.md
index b661a47b0..9fbb7d2f1 100644
--- a/README.md
+++ b/README.md
@@ -95,7 +95,7 @@ import numpy as np
 psf = kb.PSF(1.5)
 
 # Create fake data with ten 512x512 pixel images and starting at MJD of 57130.2.
-from kbmod.fake_data_creator import *
+from kbmod.fake_data.fake_data_creator import *
 fake_times = create_fake_times(10, t0=57130.2)
 ds = FakeDataSet(512, 512, fake_times)
 imgs = ds.stack.get_images()
diff --git a/notebooks/create_fake_data.ipynb b/notebooks/create_fake_data.ipynb
index 6973c51e2..d64ea33ac 100644
--- a/notebooks/create_fake_data.ipynb
+++ b/notebooks/create_fake_data.ipynb
@@ -17,7 +17,7 @@
    "source": [
     "import os\n",
     "\n",
-    "from kbmod.fake_data_creator import *\n",
+    "from kbmod.fake_data.fake_data_creator import *\n",
     "from kbmod.search import *"
    ]
   },
diff --git a/src/kbmod/fake_orbits/__init__.py b/src/kbmod/fake_data/__init__.py
similarity index 100%
rename from src/kbmod/fake_orbits/__init__.py
rename to src/kbmod/fake_data/__init__.py
diff --git a/src/kbmod/fake_data_creator.py b/src/kbmod/fake_data/fake_data_creator.py
similarity index 100%
rename from src/kbmod/fake_data_creator.py
rename to src/kbmod/fake_data/fake_data_creator.py
diff --git a/src/kbmod/fake_orbits/insert_fake_orbit.py b/src/kbmod/fake_data/insert_fake_orbit.py
similarity index 100%
rename from src/kbmod/fake_orbits/insert_fake_orbit.py
rename to src/kbmod/fake_data/insert_fake_orbit.py
diff --git a/src/kbmod/fake_orbits/pyoorb_helper.py b/src/kbmod/fake_data/pyoorb_helper.py
similarity index 100%
rename from src/kbmod/fake_orbits/pyoorb_helper.py
rename to src/kbmod/fake_data/pyoorb_helper.py
diff --git a/tests/manual_test_fake_orbits.py b/tests/manual_test_fake_orbits.py
index ff0678aec..9f0212cc1 100644
--- a/tests/manual_test_fake_orbits.py
+++ b/tests/manual_test_fake_orbits.py
@@ -10,8 +10,8 @@
 import kbmod.search as kb
 
 from kbmod.configuration import SearchConfiguration
-from kbmod.fake_orbits.insert_fake_orbit import insert_fake_orbit_into_work_unit
-from kbmod.fake_orbits.pyoorb_helper import PyoorbOrbit
+from kbmod.fake_data.insert_fake_orbit import insert_fake_orbit_into_work_unit
+from kbmod.fake_data.pyoorb_helper import PyoorbOrbit
 from kbmod.work_unit import WorkUnit
 
 # Set the image parameters.
diff --git a/tests/test_analysis_utils.py b/tests/test_analysis_utils.py
index 506202de0..fcd1225ee 100644
--- a/tests/test_analysis_utils.py
+++ b/tests/test_analysis_utils.py
@@ -1,7 +1,7 @@
 import unittest
 
 from kbmod.analysis_utils import *
-from kbmod.fake_data_creator import add_fake_object
+from kbmod.fake_data.fake_data_creator import FakeDataSet
 from kbmod.result_list import *
 from kbmod.search import *
 from kbmod.trajectory_utils import make_trajectory
@@ -85,21 +85,20 @@ def setUp(self):
 
         # image properties
         self.img_count = 10
-        self.dim_x = 15
-        self.dim_y = 20
-        self.noise_level = 1.0
-        self.variance = self.noise_level**2
-        self.p = PSF(0.5)
-
-        # create image set with single moving object
-        self.imlist = []
-        self.time_list = []
-        for i in range(self.img_count):
-            time = i / self.img_count
-            self.time_list.append(time)
-            im = LayeredImage(self.dim_x, self.dim_y, self.noise_level, self.variance, time, self.p, i)
-            self.imlist.append(im)
-        self.stack = ImageStack(self.imlist)
+        self.dim_x = 100
+        self.dim_y = 100
+
+        # Create fake images.
+        self.time_list = [i / self.img_count for i in range(self.img_count)]
+        self.fake_ds = FakeDataSet(
+            self.dim_x,
+            self.dim_y,
+            self.time_list,
+            noise_level=1.0,
+            psf_val=0.5,
+            use_seed=True,
+        )
+        self.stack = self.fake_ds.stack
 
         # Set up old_results object for analysis_utils.PostProcess
         self.num_curves = 4
@@ -179,21 +178,12 @@ def test_load_and_filter_results_lh(self):
             make_trajectory(60, 60, 0, 0, 1.0, 1.0, self.img_count),
         ]
 
-        # Create fake images with the objects in them.
-        imlist = []
-        for i in range(self.img_count):
-            t = self.time_list[i]
-            im = LayeredImage(100, 100, self.noise_level, self.variance, t, self.p, i)
-
-            # Add the objects.
-            for j, trj in enumerate(trjs):
-                add_fake_object(im, trj.x, trj.y, trj.flux, self.p)
-
-            # Append the image.
-            imlist.append(im)
+        # Add a fake object to the fake images.
+        for trj in trjs:
+            self.fake_ds.insert_object(trj)
 
         # Create the stack search and insert the fake results.
-        search = StackSearch(ImageStack(imlist))
+        search = StackSearch(self.fake_ds.stack)
         search.set_results(trjs)
 
         # Do the filtering.
diff --git a/tests/test_bilinear_interp.py b/tests/test_bilinear_interp.py
index b2d02d338..cfe1f20f3 100644
--- a/tests/test_bilinear_interp.py
+++ b/tests/test_bilinear_interp.py
@@ -2,7 +2,7 @@
 
 import numpy as np
 
-from kbmod.fake_data_creator import add_fake_object
+from kbmod.fake_data.fake_data_creator import add_fake_object
 import kbmod.search as kb
 
 
diff --git a/tests/test_data_interface.py b/tests/test_data_interface.py
index 200f573a8..cac15c8e4 100644
--- a/tests/test_data_interface.py
+++ b/tests/test_data_interface.py
@@ -10,7 +10,7 @@
     load_input_from_file,
     load_input_from_individual_files,
 )
-from kbmod.fake_data_creator import create_fake_times, FakeDataSet
+from kbmod.fake_data.fake_data_creator import create_fake_times, FakeDataSet
 from kbmod.search import *
 from kbmod.work_unit import WorkUnit
 from utils.utils_for_tests import get_absolute_data_path
diff --git a/tests/test_end_to_end.py b/tests/test_end_to_end.py
index 6b25b638b..5d8705b98 100644
--- a/tests/test_end_to_end.py
+++ b/tests/test_end_to_end.py
@@ -4,7 +4,7 @@
 import tempfile
 import unittest
 
-from kbmod.fake_data_creator import *
+from kbmod.fake_data.fake_data_creator import *
 from kbmod.run_search import *
 from kbmod.search import *
 from kbmod.trajectory_utils import make_trajectory
diff --git a/tests/test_fake_data_creator.py b/tests/test_fake_data_creator.py
index 78a51b9b8..0ca5188fa 100644
--- a/tests/test_fake_data_creator.py
+++ b/tests/test_fake_data_creator.py
@@ -2,7 +2,7 @@
 import tempfile
 import unittest
 
-from kbmod.fake_data_creator import *
+from kbmod.fake_data.fake_data_creator import *
 from kbmod.file_utils import *
 from kbmod.search import *
 from kbmod.work_unit import WorkUnit
diff --git a/tests/test_image_stack.py b/tests/test_image_stack.py
index 0f8991146..64706bf3d 100644
--- a/tests/test_image_stack.py
+++ b/tests/test_image_stack.py
@@ -1,7 +1,7 @@
 import tempfile
 import unittest
 
-from kbmod.fake_data_creator import add_fake_object
+from kbmod.fake_data.fake_data_creator import add_fake_object
 from kbmod.search import *
 
 
diff --git a/tests/test_layered_image.py b/tests/test_layered_image.py
index e29f857f9..dbc1633dc 100644
--- a/tests/test_layered_image.py
+++ b/tests/test_layered_image.py
@@ -4,7 +4,7 @@
 
 from astropy.io import fits
 
-from kbmod.fake_data_creator import add_fake_object
+from kbmod.fake_data.fake_data_creator import add_fake_object
 from kbmod.search import *
 
 
diff --git a/tests/test_readme_example.py b/tests/test_readme_example.py
index 4da0759bf..6c2614e5c 100644
--- a/tests/test_readme_example.py
+++ b/tests/test_readme_example.py
@@ -3,7 +3,7 @@
 import numpy as np
 
 import kbmod.search as kb
-from kbmod.fake_data_creator import *
+from kbmod.fake_data.fake_data_creator import *
 
 
 class test_readme_example(unittest.TestCase):
diff --git a/tests/test_regression_test.py b/tests/test_regression_test.py
index 56c099a6e..ad9c614c1 100644
--- a/tests/test_regression_test.py
+++ b/tests/test_regression_test.py
@@ -13,7 +13,7 @@
 import numpy as np
 from astropy.io import fits
 
-from kbmod.fake_data_creator import add_fake_object
+from kbmod.fake_data.fake_data_creator import add_fake_object
 from kbmod.file_utils import *
 from kbmod.result_list import ResultList
 from kbmod.run_search import SearchRunner
diff --git a/tests/test_search.py b/tests/test_search.py
index c9d2739f1..8e6985d39 100644
--- a/tests/test_search.py
+++ b/tests/test_search.py
@@ -2,7 +2,7 @@
 
 import numpy as np
 
-from kbmod.fake_data_creator import add_fake_object
+from kbmod.fake_data.fake_data_creator import add_fake_object
 from kbmod.search import *
 from kbmod.trajectory_utils import make_trajectory
 
@@ -15,7 +15,7 @@ def setUp(self):
         self.flux_error = 0.15
 
         # image properties
-        self.imCount = 20
+        self.img_count = 20
         self.dim_y = 80
         self.dim_x = 60
         self.noise_level = 4.0
@@ -38,7 +38,7 @@ def setUp(self):
         )
 
         # Add convenience array of all true bools for the stamp tests.
-        self.all_valid = [True] * self.imCount
+        self.all_valid = [True] * self.img_count
 
         # search parameters
         self.angle_steps = 150
@@ -54,8 +54,8 @@ def setUp(self):
 
         # create image set with single moving object
         self.imlist = []
-        for i in range(self.imCount):
-            time = i / self.imCount
+        for i in range(self.img_count):
+            time = i / self.img_count
             im = LayeredImage(self.dim_x, self.dim_y, self.noise_level, self.variance, time, self.p, i)
             add_fake_object(
                 im,
@@ -127,7 +127,7 @@ def test_results(self):
             self.max_angle,
             self.min_vel,
             self.max_vel,
-            int(self.imCount / 2),
+            int(self.img_count / 2),
         )
 
         results = self.search.get_results(0, 10)
@@ -150,7 +150,7 @@ def test_results_extended_bounds(self):
             self.max_angle,
             self.min_vel,
             self.max_vel,
-            int(self.imCount / 2),
+            int(self.img_count / 2),
         )
 
         results = self.search.get_results(0, 10)
@@ -173,7 +173,7 @@ def test_results_reduced_bounds(self):
             self.max_angle,
             self.min_vel,
             self.max_vel,
-            int(self.imCount / 2),
+            int(self.img_count / 2),
         )
 
         results = self.search.get_results(0, 10)
@@ -198,16 +198,12 @@ def test_set_sigmag_config(self):
 
     @unittest.skipIf(not HAS_GPU, "Skipping test (no GPU detected)")
     def test_results_off_chip(self):
-        trj = Trajectory()
-        trj.x = -3
-        trj.y = 12
-        trj.vx = 25.0
-        trj.vy = 10.0
+        trj = make_trajectory(x=-3, y=12, vx=25.0, vy=10.0)
 
         # Create images with this fake object.
         imlist = []
-        for i in range(self.imCount):
-            time = i / self.imCount
+        for i in range(self.img_count):
+            time = i / self.img_count
             im = LayeredImage(self.dim_x, self.dim_y, self.noise_level, self.variance, time, self.p, i)
             add_fake_object(
                 im,
@@ -230,7 +226,7 @@ def test_results_off_chip(self):
             self.max_angle,
             self.min_vel,
             self.max_vel,
-            int(self.imCount / 2),
+            int(self.img_count / 2),
         )
 
         # Check the results.
@@ -243,10 +239,10 @@ def test_results_off_chip(self):
 
     def test_sci_viz_stamps(self):
         sci_stamps = StampCreator.get_stamps(self.search.get_imagestack(), self.trj, 2)
-        self.assertEqual(len(sci_stamps), self.imCount)
+        self.assertEqual(len(sci_stamps), self.img_count)
 
         times = self.stack.build_zeroed_times()
-        for i in range(self.imCount):
+        for i in range(self.img_count):
             self.assertEqual(sci_stamps[i].width, 5)
             self.assertEqual(sci_stamps[i].height, 5)
 
@@ -271,7 +267,7 @@ def test_stacked_sci(self):
         # Compute the true stacked pixel for the middle of the track.
         times = self.stack.build_zeroed_times()
         sum_middle = 0.0
-        for i in range(self.imCount):
+        for i in range(self.img_count):
             t = times[i]
             x = int(self.trj.x + self.trj.vx * t)
             y = int(self.trj.y + self.trj.vy * t)
@@ -286,7 +282,7 @@ def test_stacked_sci(self):
 
     def test_median_stamps_trj(self):
         # Compute the stacked science from two trajectories (one with bad points).
-        goodIdx = [[1] * self.imCount for _ in range(2)]
+        goodIdx = [[1] * self.img_count for _ in range(2)]
         goodIdx[1][1] = 0
         goodIdx[1][5] = 0
         goodIdx[1][9] = 0
@@ -303,7 +299,7 @@ def test_median_stamps_trj(self):
         times = self.stack.build_zeroed_times()
         pix_values0 = []
         pix_values1 = []
-        for i in range(self.imCount):
+        for i in range(self.img_count):
             t = times[i]
             x = int(self.trj.x + self.trj.vx * t)
             y = int(self.trj.y + self.trj.vy * t)
@@ -312,8 +308,8 @@ def test_median_stamps_trj(self):
                 pix_values0.append(pixVal)
             if pixVal != KB_NO_DATA and goodIdx[1][i] == 1:
                 pix_values1.append(pixVal)
-        self.assertEqual(len(pix_values0), self.imCount)
-        self.assertEqual(len(pix_values1), self.imCount - 3)
+        self.assertEqual(len(pix_values0), self.img_count)
+        self.assertEqual(len(pix_values1), self.img_count - 3)
 
         # Check that we get the correct answer.
         self.assertAlmostEqual(np.median(pix_values0), medianStamps0.get_pixel(2, 2), delta=1e-5)
@@ -321,11 +317,7 @@ def test_median_stamps_trj(self):
 
     def test_median_stamps_no_data(self):
         # Create a Trajectory that goes through the masked pixels.
-        trj = Trajectory()
-        trj.x = self.masked_x
-        trj.y = self.masked_y
-        trj.vx = 0
-        trj.vy = 0
+        trj = make_trajectory(x=self.masked_x, y=self.masked_y, vx=0.0, vy=0.0)
 
         # Compute the stacked science from a single Trajectory.
         medianStamp = StampCreator.get_median_stamp(self.search.get_imagestack(), trj, 2, self.all_valid)
@@ -334,18 +326,18 @@ def test_median_stamps_no_data(self):
 
         # Compute the true median pixel for the middle of the track.
         pix_values = []
-        for i in range(self.imCount):
+        for i in range(self.img_count):
             pixVal = self.imlist[i].get_science().get_pixel(self.masked_y, self.masked_x)
             if pixVal != KB_NO_DATA:
                 pix_values.append(pixVal)
-        self.assertEqual(len(pix_values), self.imCount / 2)
+        self.assertEqual(len(pix_values), self.img_count / 2)
 
         # Check that we get the correct answer.
         self.assertAlmostEqual(np.median(pix_values), medianStamp.get_pixel(2, 2), delta=1e-5)
 
     def test_mean_stamps_trj(self):
         # Compute the stacked science from two trajectories (one with bad points).
-        goodIdx = [[1] * self.imCount for _ in range(2)]
+        goodIdx = [[1] * self.img_count for _ in range(2)]
         goodIdx[1][1] = 0
         goodIdx[1][5] = 0
         goodIdx[1][9] = 0
@@ -364,7 +356,7 @@ def test_mean_stamps_trj(self):
         pix_sum1 = 0.0
         pix_count0 = 0.0
         pix_count1 = 0.0
-        for i in range(self.imCount):
+        for i in range(self.img_count):
             t = times[i]
             x = int(self.trj.x + self.trj.vx * t)
             y = int(self.trj.y + self.trj.vy * t)
@@ -375,8 +367,8 @@ def test_mean_stamps_trj(self):
             if pixVal != KB_NO_DATA and goodIdx[1][i] == 1:
                 pix_sum1 += pixVal
                 pix_count1 += 1
-        self.assertEqual(pix_count0, self.imCount)
-        self.assertEqual(pix_count1, self.imCount - 3)
+        self.assertEqual(pix_count0, self.img_count)
+        self.assertEqual(pix_count1, self.img_count - 3)
 
         # Check that we get the correct answer.
         self.assertAlmostEqual(pix_sum0 / pix_count0, meanStamp0.get_pixel(2, 2), delta=1e-5)
@@ -394,12 +386,12 @@ def test_mean_stamps_no_data(self):
         # Compute the true median pixel for the middle of the track.
         pix_sum = 0.0
         pix_count = 0.0
-        for i in range(self.imCount):
+        for i in range(self.img_count):
             pixVal = self.imlist[i].get_science().get_pixel(self.masked_y, self.masked_x)
             if pixVal != KB_NO_DATA:
                 pix_sum += pixVal
                 pix_count += 1.0
-        self.assertEqual(pix_count, self.imCount / 2.0)
+        self.assertEqual(pix_count, self.img_count / 2.0)
 
         # Check that we get the correct answer.
         self.assertAlmostEqual(pix_sum / pix_count, meanStamp.get_pixel(2, 2), delta=1e-5)
@@ -478,11 +470,7 @@ def test_coadd_cpu_simple(self):
         all_valid = [True, True, True]  # convenience array
 
         # One Trajectory right in the image's middle.
-        trj = Trajectory()
-        trj.x = 1
-        trj.y = 1
-        trj.vx = 0
-        trj.vy = 0
+        trj = make_trajectory(x=1, y=1, vx=0.0, vy=0.0)
 
         # Basic Stamp parameters.
         params = StampParameters()
@@ -538,11 +526,7 @@ def test_coadd_gpu_simple(self):
         all_valid = [True, True, True]  # convenience array
 
         # One Trajectory right in the image's middle.
-        trj = Trajectory()
-        trj.x = 1
-        trj.y = 1
-        trj.vx = 0
-        trj.vy = 0
+        trj = make_trajectory(x=1, y=1, vx=0.0, vy=0.0)
 
         # Basic Stamp parameters.
         params = StampParameters()
@@ -607,7 +591,7 @@ def test_coadd_cpu(self):
                 pix_sum = 0.0
                 pix_count = 0.0
                 pix_vals = []
-                for i in range(self.imCount):
+                for i in range(self.img_count):
                     t = times[i]
                     x = int(self.trj.x + self.trj.vx * t) + x_offset
                     y = int(self.trj.y + self.trj.vy * t) + y_offset
@@ -664,7 +648,7 @@ def test_coadd_gpu(self):
                 pix_sum = 0.0
                 pix_count = 0.0
                 pix_vals = []
-                for i in range(self.imCount):
+                for i in range(self.img_count):
                     t = times[i]
                     x = int(self.trj.x + self.trj.vx * t) + x_offset
                     y = int(self.trj.y + self.trj.vy * t) + y_offset
@@ -690,7 +674,7 @@ def test_coadd_cpu_use_inds(self):
         params.stamp_type = StampType.STAMP_MEAN
 
         # Mark a few of the observations as "do not use"
-        inds = [[True] * self.imCount, [True] * self.imCount]
+        inds = [[True] * self.img_count, [True] * self.img_count]
         inds[0][5] = False
         inds[1][3] = False
         inds[1][6] = False
@@ -713,7 +697,7 @@ def test_coadd_cpu_use_inds(self):
                 sum_1 = 0.0
                 count_0 = 0.0
                 count_1 = 0.0
-                for i in range(self.imCount):
+                for i in range(self.img_count):
                     t = times[i]
                     x = int(self.trj.x + self.trj.vx * t) + x_offset
                     y = int(self.trj.y + self.trj.vy * t) + y_offset
@@ -741,7 +725,7 @@ def test_coadd_gpu_use_inds(self):
         params.stamp_type = StampType.STAMP_MEAN
 
         # Mark a few of the observations as "do not use"
-        inds = [[True] * self.imCount, [True] * self.imCount]
+        inds = [[True] * self.img_count, [True] * self.img_count]
         inds[0][5] = False
         inds[1][3] = False
         inds[1][6] = False
@@ -764,7 +748,7 @@ def test_coadd_gpu_use_inds(self):
                 sum_1 = 0.0
                 count_0 = 0.0
                 count_1 = 0.0
-                for i in range(self.imCount):
+                for i in range(self.img_count):
                     t = times[i]
                     x = int(self.trj.x + self.trj.vx * t) + x_offset
                     y = int(self.trj.y + self.trj.vy * t) + y_offset
diff --git a/tests/test_search_encode.py b/tests/test_search_encode.py
index 168770d1a..c7456cef0 100644
--- a/tests/test_search_encode.py
+++ b/tests/test_search_encode.py
@@ -2,7 +2,7 @@
 
 import numpy as np
 
-from kbmod.fake_data_creator import FakeDataSet
+from kbmod.fake_data.fake_data_creator import FakeDataSet
 from kbmod.search import *
 from kbmod.trajectory_utils import make_trajectory
 
diff --git a/tests/test_search_filter.py b/tests/test_search_filter.py
index 0ed248f9f..8de4c232a 100644
--- a/tests/test_search_filter.py
+++ b/tests/test_search_filter.py
@@ -2,7 +2,7 @@
 
 import numpy as np
 
-from kbmod.fake_data_creator import FakeDataSet
+from kbmod.fake_data.fake_data_creator import FakeDataSet
 from kbmod.search import *
 from kbmod.trajectory_utils import make_trajectory
 
diff --git a/tests/test_stamp_filters.py b/tests/test_stamp_filters.py
index 829326251..174872a2e 100644
--- a/tests/test_stamp_filters.py
+++ b/tests/test_stamp_filters.py
@@ -2,7 +2,7 @@
 import unittest
 
 from kbmod.configuration import SearchConfiguration
-from kbmod.fake_data_creator import add_fake_object, create_fake_times, FakeDataSet
+from kbmod.fake_data.fake_data_creator import add_fake_object, create_fake_times, FakeDataSet
 from kbmod.filters.stamp_filters import *
 from kbmod.result_list import *
 from kbmod.search import *
diff --git a/tests/test_stamp_parity.py b/tests/test_stamp_parity.py
index 2844af2e7..cfe709326 100644
--- a/tests/test_stamp_parity.py
+++ b/tests/test_stamp_parity.py
@@ -8,7 +8,7 @@
 
 import numpy as np
 
-from kbmod.fake_data_creator import FakeDataSet
+from kbmod.fake_data.fake_data_creator import FakeDataSet
 from kbmod.search import *
 from kbmod.trajectory_utils import make_trajectory
 
diff --git a/tests/test_work_unit.py b/tests/test_work_unit.py
index 62e0716e8..e3583383e 100644
--- a/tests/test_work_unit.py
+++ b/tests/test_work_unit.py
@@ -9,7 +9,7 @@
 import warnings
 
 from kbmod.configuration import SearchConfiguration
-from kbmod.fake_data_creator import make_fake_wcs_info
+from kbmod.fake_data.fake_data_creator import make_fake_wcs_info
 import kbmod.search as kb
 from kbmod.work_unit import hdu_to_raw_image, raw_image_to_hdu, WorkUnit