Resolve "Which frame are the injection parameters supposed to be in?"

docs/transient-gw-data.txt

@@ -91,6 +91,21 @@ You can also set the strain data without any noise at all
 Injecting a signal
 ------------------
 
-If you wish to inject a signal into the data, you can use this function
+If you wish to inject a signal into the data, you can use this function:
 
    >>> bilby.gw.detector.Interferometer.inject_signal
+
+To inject a signal a `bilby.gw.waveform_generator.WaveformGenerator` is required.
+This is where you must specify the injection's duration, start-time, waveform.
+Additionally, a `parameter_conversion` function can be passed. The default is :code:`parameter_conversion = bilby.gw.conversion.convert_to_lal_binary_black_hole_parameters`.
+This expects injection parameters to be provided in the detector-frame, e.g.
+
+.. code-block:: python
+
+    >>> parameters = dict(
+        mass_1=36., mass_2=29.,
+        a_1=0.4, a_2=0.3, tilt_1=0.5, tilt_2=1.0, phi_12=1.7, phi_jl=0.3,
+        luminosity_distance=2000., theta_jn=0.4, psi=2.659,
+        phase=1.3, geocent_time=1126259642.413, ra=1.375, dec=-1.2108
+        )
+