The Louisiana Space Consortium Student Sounding Balloon Program

Since the fall of 2003 the Louisiana Aerospace Catalyst Experiences for Students (LaACES) program has been providing university students a two semester project that culminates with the flight of a scientific balloon experiment. During the first semester students complete the Student Ballooning Course (SBC) which teaches basic skills necessary to develop a working scientific payload. The SBC consists of a series of lectures and activities providing instruction in electronics, programming, project management, balloon payload design, and introductory circuit assembly. The SBC introduces the BalloonSat, a sub-assembly designed at LSU for LaACES which contains a microcontroller, real-time clock and a four channel analog-to-digital converter. The second semester is spent on the design, development, testing and calibration of the payloads. Upon completion of the Flight Readiness Review, students travel to the NASA Columbia Scientific Balloon Facility (CSBF) in Palestine, Texas for integration, launch, recovery and science presentations. A flight capable Automatic Packet Reporting System (APRS) radio beacon armed with GPS and command capable cut down was developed to track the balloon during flight and to cut-down the payloads. Tracking vehicles are outfitted with radios tuned to APRS frequency and laptops displaying maps of the payload location. Here we describe LaACES; program development, tools and technologies, implementation, program, management issues and flight experiences.

Solving the Multilateration Problem without Iteration

The process of positioning, using only distances from control stations, is called trilateration (or multilateration if the problem is over-determined). The observation equation is Pythagoras’s formula, in terms of the summed squares of coordinate differences and, thus, is nonlinear. There is one observation equation for each control station, at a minimum, which produces a system of simultaneous equations to solve. Over-determined nonlinear systems of simultaneous equations are typically solved using iterative least squares after forming the system as a truncated Taylor’s series, omitting the nonlinear terms. This paper provides a linearization of the observation equation that is not a truncated infinite series—it is exact—and, thus, is solved exactly, with full rigor, without iteration and, thus, without the need of first providing approximate coordinates to seed the iteration. However, there is a cost of requiring an additional observation beyond that required by the non-linear approach. The examples and terminology come from terrestrial land surveying, but the method is fully general: it works for, say, radio beacon positioning, as well. The approach can use slope distances directly, which avoids the possible errors introduced by atmospheric refraction into the zenith-angle observations needed to provide horizontal distances. The formulas are derived for two- and three-dimensional cases and illustrated with an example using total-station and global navigation satellite system (GNSS) data.

Radio engineering support of aircraft flights and aviation telecommunications

The training manual describes the basics of radio engineering support for flights, the organization of radio engineering support for flights, and the general characteristics of flight support equipment. Information is provided about drive radios, marker beacons, radio beacon landing systems, automatic direction finders, RSBN system, VOR and DME beacons, satellite navigation systems, as well as radar surveillance equipment. The basics of telecommunications, issues of aviation telecommunications, as well as information about the means of aviation telecommunications are presented. There are questions for self-control. It is intended for students studying under the specialty program in the specialty 25.05.05 "Aircraft operation and air traffic management"; for students studying under the bachelor's program in the direction of training 25.03.04 "Airport operation and aircraft flight support", as well as for students studying under the master's program in the direction 25.04.04 "Airport Operation and aircraft flight support".

Amplitude-polarization method of the moving object pitch detection

There is discussed the amplitude-polarization method of a moving object pitch angle detection using the radio beacon horizontally polarized signals. The moving object pitch angle estimation is done using the ratio of the in-phase orthogonal horizontal linearly polarized radio beacon amplitudes of the signals received within the linearly polarized basis.

On the radio beacon technique for refinement the orbit of an asteroid

Приводятся аргументы в пользу неизбежной интенсификации полетов к астероидам. Это обусловлено ростом внимания к проблеме астероидно-кометной опасности, а также быстрым ростом интереса к освоению астероидных ресурсов. Массовость полетов ставит задачу оптимизации технологии уточнения параметров движения астероидов. Метод радиопередатчика (маяка), размещенного на околоастероидной орбите, позволяет уточнить положение астероида по сравнению с обычными средствами на 2-3 порядка. Отработка такой возможности была заложена в космическом проекте «Апофис», который ранее предлагался для включения в Федеральную космическую программу, а сейчас может быть частично реализован в рамках проекта «Бумеранг». Arguments are given in favor of the inevitable intensification of flights to the asteroids. This is due to the growing attention to the problem of asteroid/comet hazard, as well as the rapid growth of interest in exploration of asteroid resources. The massive flights require an optimal technology for refining the motion parameters of asteroid. The method of a radio transmitter (beacon) placed into a near-asteroid orbit makes it possible to refine the position of the asteroid by 2-3 orders of magnitude in comparison to conventional techniques. Working out this possibility was laid down in the “Apophis” space project, which was previously proposed for inclusion in the Federal space program, and now can be implemented in the “Boomerang” project.

A Distributed Radio Beacon/IMU/Altimeter Integrated Localization Scheme with Uncertain Initial Beacon Locations for Lunar Pinpoint Landing

As a growing number of exploration missions have successfully landed on the Moon in recent decades, ground infrastructures, such as radio beacons, have attracted a great deal of attention in the design of navigation systems. None of the available studies regarding integrating beacon measurements for pinpoint landing have considered uncertain initial beacon locations, which are quite common in practice. In this paper, we propose a radio beacon/inertial measurement unit (IMU)/altimeter localization scheme that is sufficiently robust regarding uncertain initial beacon locations. This scheme was designed based on the sparse extended information filter (SEIF) to locate the lander and update the beacon configuration at the same time. Then, an adaptive iterated sparse extended hybrid filter (AISEHF) was devised by modifying the prediction and update stage of SEIF with a hybrid-form propagation and a damping iteration algorithm, respectively. The simulation results indicated that the proposed method effectively reduced the error in the position estimations caused by uncertain beacon locations and made an effective trade-off between the estimation accuracy and the computational efficiency. Thus, this method is a potential candidate for future lunar exploration activities.