MST radar vary considerably from one installation to the next in the type of hardware, operating schedule, associated personnel, and amount of funding. Most such systems do not have the computing power to decode in software when the decoding must be performed for each received pulse, as is required for certain sets of phase codes. These sets allow one to obtain the best signal-to-sidelobe ratio when operating at the minimum baud length allowed by the bandwidth of the transmitter. We discuss here a number of realizations of the hardware phase decoder, and discuss the applicability of each to decoding MST radar signals. We present a new design for a decoder which is very inexpensive to build, easy to add to an existing system and is capable of decoding on each received pulse using codes with a baud length as short as one microsecond.

In this paper we discuss many aspects of codes and decoding and their applications to MST experimenta. This includes Barker codes and longer individual codes, and then complementary codes and other code sets. We discuss software decoding and also hardware decoders and coherent integrators.

In October 1997 and July 1999 during the STS-86 and STS-93 flights of the Space Shuttle, the crew performed experiments with controlled ion injections over the incoherent scatter radar (ISR) facilities located at Arecibo, Puerto Rico; Jicamarca, Perú; and Kwajalein, Marshall Islands. Ion beams were formed by charge exchange in the ionosphere of the high velocity neutral molecules exhausted by the Orbital Maneuver Subsystem (OMS) engines on the Space Shuttle. Pick-up ions were produced with energies between 2 and 10 eV depending on the orientation of the OMS engines relative to the vehicle orbit. The ions eventually recombined with electrons yielding electrón density depressions or holes.

Diapositivas presentadas en el 2010 CEDAR Workshop, University of Colorado, Boulder, CO, 20-25 June 2010.

We present observations of the F‐region ionosphere over Arecibo, Puerto Rico (18.34°N, 66.75°W), during the January–February 2008 and January–February 2009 sudden stratospheric warming (SSW) events. For the first period (2008), we have used incoherent scatter radar (ISR) electron density and temperature measurements from the Arecibo Observatory (AO), as well as relative total electron content (TEC) derived from a dual‐frequency GPS receiver. For the second event (2009), during which we observed the largest recorded stratospheric warming, we have used the relative GPS TEC. Our analysis indicates that the ionosphere over Arecibo exhibits perturbations after the SSW, the effects are most visible during the daytime. The strongest signatures are observed in the TEC measurements, represented by large enhancements (with respect to non SSW days), particularly during daytime hours. Howe...

We have made 16 unsuccessful attempts, in February and October 2003, and February 2004, to observe solar echoes using the 50 MHz radar at Jicamarca in Peru. The upper bound that we have determined on the solar cross section is significantly lower than the average of earlier reported observations. In this paper we will describe the observations, discuss the noise and interference from solar bursts, and suggest possible reasons why the echo might be weaker than expected.