In general, meteors occur when meteoroids (interstellar debris) enter Earth's atmosphere and burn up at altitudes between 100 and 120 km. As a meteor enters the atmosphere, a plasma cloud forms, and using the 440 UHF Millstone Hill radar we can study the echoes off this plasma cloud, known as meteor head echoes. We focus on the 1999 Leonid meteor shower which occurred from November 18th to the 20th. We will describe the data reduction process which includes several specialized computer programs, and we will present statistics on the altitude, frequency and strength of the meteor echoes seen. We will compare these results to similar studies of meteor head echoes at other incoherent scatter radars and will highlight unique features of the 1999 Leonid shower as viewed from Millstone Hill.
Verification of Seasonal Dependancies of the Millstone Hill ISR Model
Charles M. Werneth
University of Southern Mississippi (MS)
A model of scalar parameters such as electron density, electron temperature, and ion temperature has been constructed using data taken with the Millstone Hill Incoherent Scatter Radars (ISR). The ISR data used for this model have been stored in the madrigal database--a publicly accessible database created by Millstone Hill for atmospheric research. This model, designed by John Holt, Cynthia Rudin, and Michael Buonsanto, has been written such that seasonal profiles of the aforementioned scalar quantities could be easily accessed and studied. Upon analyzing the data and code, however, one discovers that implementation of the fitting algorithm may not independently separate data seasonally and may be a source of seasonal contamination. The purpose of this research project has been to modify the model to separate the seasonal data into corresponding output files and to determine if the original model's seasonal predictions differ from the new model's seasonal predictions.
Real-Time Access and Display of Remote-site Geophysical Data
Daron Vroon
Hope College (MI)
The Millstone Observatory contains several instruments which complement the research done here using the high-power radars. Among these are a magnetometer belonging to the Florida Institute of Technology and an all-sky imager belonging to Boston University. The goal of this project was to find a way to access the data from these instruments and create a web-based tool for viewing it in real-time. New networking hardware was installed and configured on FIT's computer to give access to the magnetometer data. Methods involving file sharing and FTP were utilized to retrieve the all- sky imager data. A Java program was written to update the real-time display and parse the incoming data for installation into the Madrigal Database. Also, a Java servlet was created to access and display the archived data.
SKA Design and Data Redundancy Simulation
David R. Law
University of Virginia (VA)
When completed, the Square Kilometer Array (SKA) will be capable of an imaging power far greater than that of any radio telescope array today. Comprised of approximately 1000 antenna stations spaced over a distance of order 1000 kilometers, it is significantly different from current arrays, and so requires extensive research to realize all of the characteristics of such a large n array. As this array will possess a far greater dynamic range than any other, it must therefore be calibrated to a finer degree as well, rendering new automated methods more desirable. Data redundancies in the form of UV line crossings (while usually of minimal importance for smaller arrays) become significant for arrays of this size, and characterizing these crossing points can potentially prove to be of key importance in the effective calibration of such an array. This paper begins a preliminary investigation into these crossing points, detailing how they are affected by such factors as the number of antenna stations and the length of integration time, and presents some comparisons of their behavior for a variety of different array configurations.
Java Software for the Madrigal Database
Thomas Briggs
Amherst College (MA)
Servlets are a method of adding "intelligence" -- dynamic content generation -- to Web pages. Written in the Java language, servlets reside on the Web server, waiting for Web browsers to request information from them. Unlike normal Web pages, though, servlets can look at input passed to them as they are called, and hence can react to user-submitted data in the form of menus, text fields, etc.. Anyone who has used a Web search engine or online order form is familiar with this principle. The servlet interface for the Madrigal database written for Haystack last year has been rewritten as a more full-featured version capable of processing virtually any user request. The database itself has been updated correspondingly, moving from a flat-file model to a relational database using MySQL.
Development of Real-Time Analysis and Display
S. Daniel Daugherty II
University of Alabama, Huntsville
Millstone Hill Observatory utilizes several optical instruments in gathering atmospheric wind and temperature measurements. Previously the data acquisition and analysis had been separate processes. My job for the summer was a software project in which the primary goal was to have the acquisition program and analysis program run concurrently so that the results of the measurements could be made available in real-time. Originally I undertook the task of translating the analysis programs from PASCAL to a more efficient and compatible C++, but this proved too time consuming. Next I decided to modify the existing PASCAL programs to analyze the data as it came in from the acquisition program, but feeling more comfortable writing in C++, I chose to write an intermediary program. This program reads the incremental data from the acquisition program and writes it to a temporary file until significant data is received, at which point the PASCAL program is called to analyze the data, making it effectively run in near real-time.
SMALL RADIO TELESCOPE
Rodolfo Montez Jr.
University of Texas at Austin (TX)
ABSTRACT (A) Electronic Calibrator for the Small Radio Telescope
An electronic noise calibrator for MIT Haystack Observatory's Small Radio Telescope (SRT) is described. The electronic noise calibrator replaces the existing vane calibrator. A noise diode and a small dipole antenna emit a signal at 21 cm wavelength. The result is a calibrator that functions quickly, efficiently, and in conditions problematic to the vane calibrator. Circuit diagrams, components, and construction are presented. This research was carried out as part of the National Science Foundation's Research Experience for Undergraduates (REU) Program at MIT Haystack Observatory.
ABSTRACT (B) Modeling the Spillover Temperature for the SRT
A model for the spillover temperature for MIT Haystack Observatory's Small Radio Telescope (SRT) is described. The spillover temperature, Tspillover, is radiation the receiver detects other than that reflected from the dish. The model evaluates Tspillover over all elevations. The model can also be applied to whole data sets to incorporate more realistic values of Tspillover. The end results are constant values of the receiver's temperature, Treceiver, for all elevations. This research was carried out as part of the National Science Foundation's Research Experience for Undergraduates (REU) Program at MIT Haystack Observatory.
7-mm VLBI Studies of Mira's (Ceti) Stellar Envelope
Julia Gardner
Smith College (MA)
Over a period of 6 months in 1999-2000, six epochs of VLBI data at 43 GHz were taken of v=1 and v=2 SiO maser emission around Mira (o Ceti). Images were created from each epoch and registered to study the motion of the masing regions within Mira's stellar envelope. In each transition, the masing regions appeared in a broken, 0.060 - 0.080 arcsecond ring about the star. The data encompasses a period of time in which Mira peaks in visual wavelengths. The peak for the SiO masers lagged behind the visual peak, as expected. However, this lag was different between the v=1 and v=2 vibrational states. These images, which resemble a stop-action movie of Mira's masing regions, are the highest fidelity look into its envelope achieved to date.
Probing the Molecular Outflow in Orion-KL with SiO Masers
Whitney Raas
University of California, Los Angeles (CA)
SiO masers are found in only three star forming regions and occur veryclose to young stars and are therefore one of the few ways to obtain information regarding the environment around these stars. We have observed SiO masers in the Orion KL Nebula and present high resolution images of the 3mm (86.2 GHz) transition as well as the 7mm (43.1 GHz) transition (v=1, J=2-1 and v=1, J=1-0, respectively). Emission from both the 3mm and 7mm lines forms in a distinctive "X" morphology thought to represent the outlines of a bipolar conical outflow. Comparison of the two transitions also plainly shows that in all regions where emission is present, the two maser lines are not cospatial. Both masers form around the center source, believed to be a young star, but the 3mm emission is consistently found outside the 7mm emission, further from the source. The location of the different emission lines can provide new evidence for an explanation of how the masers form, as well as help to describe the temperature, density, and dynamics of the Orion Nebula.