diff --git a/ObservationSim/MockObject/CatalogBase.py b/ObservationSim/MockObject/CatalogBase.py
index fda284966584ca9a7946307fa8a298eb4a38dd3c..a0a2d16d18e2bacb81ce5f8c835a51cd4e77bcdf 100644
--- a/ObservationSim/MockObject/CatalogBase.py
+++ b/ObservationSim/MockObject/CatalogBase.py
@@ -64,7 +64,7 @@ class CatalogBase(metaclass=ABCMeta):
             "bulgemass": 0.,
             "diskmass": 0.,
             "size": 0.,
-            "detA": 0.,
+            "detA": 1.,
             "type": 0,
             "veldisp": 0.,
             "coeff": np.zeros(20),