have model obs fill in filter

rubin_scheduler/scheduler/model_observatory/model_observatory.py

@@ -141,6 +141,9 @@ class ModelObservatory:
         will allow altitudes anywhere between 20-86 degrees.
     telescope : `str`
         Telescope name for rotation computations. Default "rubin".
+    band2filter : `dict`
+        Dictionary for converting band names to filter names. 
+        Default of none will use band names for filter names.
     """
 
     def __init__(
@@ -168,6 +171,7 @@ def __init__(
         sky_alt_limits=None,
         sky_az_limits=None,
         telescope="rubin",
+        band2filter=None,
     ):
         self.nside = nside
 
@@ -179,6 +183,12 @@ def __init__(
             mjd = mjd_start
 
         self.bandlist = ["u", "g", "r", "i", "z", "y"]
+        if band2filter is None:
+            self.band2filter = {}
+            for bandname in self.bandlist:
+                self.band2filter[bandname] = bandname
+        else:
+            self.band2filter = band2filter
 
         self.cloud_limit = cloud_limit
         self.no_sky = no_sky
@@ -550,6 +560,8 @@ def observation_add_data(self, observation):
         )
         observation["moonPhase"] = sun_moon_info["moon_phase"]
 
+        observation["filter"] = self.band2filter[observation["band"][0]]
+
         observation["ID"] = self.obs_id_counter
         self.obs_id_counter += 1