An all sky camera concept for the detection and localization of gamma ray bursts from a single spacecraft in near‐Earth orbit is described. The system is a refinement of one previously described and consists of three units each containing a position sensitive detector plus a coded aperture and an imaging modulation collimator. Monte Carlo simulations indicate that the instrument will provide positions based upon measurements in the 20‐100 keV band that are precise to 10 seconds of arc or better for bursts as strong as the Apollo 16 event. Such precision is expected for about six bursts per year, while more than thirty per year will be detected with a location precision of a few arc minutes. The addition of an uncollimated fourth detector identical to the other three will add a high throughput (375 cm3net effective area) moderately high resolution (4% FWHM) spectroscopy capability for the energy range 35‐100 keV where cyclotron features are expected to be most prominent. We also describe a more sensitive all sky soft (2‐6 keV) X‐ray camera which is capable of monitoring the X‐ray afterglows of gamma ray bursts as well as all X‐ray bursts, transients, and steady sources.