A key feature of the National Polar-orbiting Operational Environmental Satellite System (NPOESS) is the Northrop Grumman Space Technology patent-pending data collection architecture known as ‘SafetyNet^TM‘. The centerpiece of SafetyNet^TM is the system of fifteen globally-distributed ground receptors developed by Raytheon Company. These receptors or antennae will collect up to five times as much environmental data approxi-mately four times faster than current polar-orbiting weather satellites. Once collected, these data will be forwarded near-instantaneously to U.S. weather centrals via global fiber optic network for processing and production of data records for use in environmental prediction models.

Key system design factors:

The NPOESS SafetyNet^TM architecture provides:

o Frequent downlinks and maximizes contact duration (>100% margin) at low cost,

o Downlink bandwidth margin that allows all Stored Mission Data to be down linked to two separate receptors and

o Minimal latency impacts from loss of multiple ground receptors.

Other notable characteristics of SafetyNet^TM:

o Simple, receive-only, Ka Band receptor design provides autonomous operations

o Fifteen locations in ten countries; full-motion to track polar satellites

o Reliable and timely collection, delivery and processing of quality data

o 75% of NPOESS data products delivered to the US's weather centrals within 15 minutes; the rest in under 30 minutes

Presentation will show:

• A graphic of SafetyNet^TM within the NPOESS program architecture

• A depiction of the NPOESS data download scheme

• A map of the worldwide SafetyNet^TM receptor locations

• A graph of the percent of NPOESS Environmental Data Records (EDRs) versus time from observation to delivery

• A example chart of the NPOESS data downlink patterns to SafetyNet^TM receptors

• Example photos of SafetyNet^TM receptor antennae and radomes