added support for new nirc2 real-time controller header keywords

nirc2_reduce/data/header_kw_dicts/nirc2_newrtc.yaml

@@ -0,0 +1,26 @@
+---
+object: OBJECT
+instrument: INSTRUME
+observer: OBSERVER
+date: DATE-OBS
+time: DATE-BEG
+filter: FILTER
+wl: EFFWAVE
+subc: NAXIS1
+itime: ITIME
+coadds: COADDS
+isdome:
+  kw: AXESTAT
+  yesdome: not controlling
+  nodome: tracking
+lamps:
+  kw: FLSPECTR
+  lampon: "on"
+  lampoff: "off"
+shutter:
+  kw: SHRNAME
+  shutopen: "open"
+  shutclose: "closed"
+warpx_file: nirc2_distort_X_post20150413_v1.fits
+warpy_file: nirc2_distort_Y_post20150413_v1.fits
+dfits_kws: ["OBJECT", "DATE-OBS", "FILTER", "EFFWAVE", "NAXIS1", "ITIME", "COADDS", "AXESTAT", "FLSPECTR", "SHRNAME", "DATE-BEG", "OBSERVER"]

nirc2_reduce/flats.py

@@ -33,9 +33,7 @@ def __init__(self, fnames_off, fnames_on):
         off = np.nanmedian(self.frames_off, axis=0)
         on = np.nanmedian(self.frames_on, axis=0)
         if (np.nanmean(on) - np.nanmean(off))/np.nanmean(on) < 0.01:
-            warnings.warn(f'brightness difference between domeflaton and domeflatoff is near zero \
-            for flat including fname {fnames_on[0]}. setting to off. \
-            if this is a thermal filter (lp, ms) then this is probably ok')
+            warnings.warn(f'brightness difference between domeflaton and domeflatoff is near zero for flat including fname {fnames_on[0]}. setting to off. if this is a thermal filter (lp, ms) then this is probably ok', stacklevel=2)
             flat = off
         else:
             flat = on - off

nirc2_reduce/observation.py

@@ -379,7 +379,11 @@ def com_crop_final(self, wx, wy=None, cutoff=None):
 
         data_to_calc = np.copy(self.final)
         data_to_calc[data_to_calc < 10*cutoff] = 0.0
-        com = center_of_mass(data_to_calc)
+        if np.sum(data_to_calc) == 0.0:
+            # prevents failures when low SNR
+            com = (self.final.shape[0]/2, self.final.shape[1]/2)
+        else:
+            com = center_of_mass(data_to_calc)
 
         self.final = self.final[int(com[0]-wy):int(com[0]+wy), int(com[1]-wx):int(com[1]+wx)]