The existence of the POPPY program was declassified by the NRO in September 2005, although most of the details about its capabilities and operation are still classified. The NRO revealed, though, that the POPPY satellites, like other US signals intelligence (SIGINT) systems, used the principle of signals time difference of arrival, which enables precise locating of an object.[1]
All POPPY launches orbited multiple satellites.[2] The first POPPY launch included two satellites, launch #2 and #3 three satellites each, and subsequent launches orbited four satellites each.[3]
The full configuration thus employed four vehicles in low Earth orbit.[4]
There were seven launches of POPPY satellites from Vandenberg Air Force Base from 1962 until 1971, all of which were successful.[2] The program continued until August 1977.
Satellite blocks
The size and capabilities (in particular radio frequency coverage) of the POPPY satellites evolved over the course of the 19-year program. Block I POPPY satellites had a diameter of 20 inches (51 cm), identical to the diameter of the GRAB satellites. Two Block I satellites were launched with the first and third POPPY launch (Composite 2 and Composite 4), and one with the second POPPY launch (Composite 3). Block II POPPY satellites had a diameter of 24 inches (61 cm) and an increased weight. Two Block II satellites were launched on the second POPPY launch (Composite 3), one each on the third and fifth POPPY launch (Composite 4 and 6), and four on the fourth POPPY launch (Composite 5). Block III POPPY satellites had a diameter of 27 inches (69 cm) and again an increased weight. Three Block III satellites were launched on the fifth POPPY launch (Composite 6), and four each on the sixth and seventh POPPY launches (Composite 7 and 8).[3]
Ammoniamicrothrusters were used for station keeping in order to maintain the orbital configuration of the POPPY constellation. Satellites used 2- or 3-axis gravity gradient stabilization.[3]
POPPY Block I (NRL Composite 2)
POPPY Block II (NRL Composite 3)
POPPY Block II (NRL Composite 3)
POPPY 3 (NRL Composite 4)
POPPY 4C (NRL Composite 5)
POPPY 4D (NRL Composite 5)
POPPY 7 (NRL Composite 8)
Ground stations
POPPY satellites functioned in a store-and-dump mode. They recorded and stored data while passing over a target area, and later transmitted or "dumped" this stored information during their pass over a ground station. Known POPPY ground stations were located in Adak, AK, Lajes Field, Azores, Portugal, Edzell, Scotland, and Todendorf, Germany.[5]
Data collection and analysis
Among POPPY's tasks was the detection of signals originating from Soviet early warning radars located along the coastal regions of the USSR. Noticeable discoveries were the first recordings of the HEN HOUSE and TALL KING radars. In the operations building at each ground station, the recorded signals were analysed using Sonographs and Spectrum analyzers, and then compared with already known Emitter Library Notations (ELNOT). The analysis results were then sent under the Byeman Control System to NRL, where Signal Analysis Reports were created.[5]
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