Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Implementation of a Low-Cost Flight Tracking System for High-Altitude
  Ballooning   High altitude balloons (HABs) are typically tracked via GPS data sent via
real-time radio-based communication systems such as the Automated Packet
Reporting System (APRS). Prefabricated APRS-compatible tracker modules have
made it trivial to transmit GPS coordinates and payload parameters in
compliance with the requisite AX.25 protocol. However, in order to receive and
track APRS signals, conventional methodologies call for the use of a Very High
Frequency (VHF) receiver to demodulate signals transmitted on the 440/144 MHz
APRS frequencies, along with a compatible antenna and custom methodology for
visualizing the HAB's location on a map. The entire assembly is typically
costly, cumbersome, and may require an internet connection in order to obtain
real-time visualization of the HAB's location. This paper describes a low-cost,
handheld system based on open-source software that operates independently of an
internet connection. The miniaturized system is suited to tracking done either
from a vehicle or on foot, and is cost-effective enough to be within the means
of nearly any HAB user. The paper also discusses preliminary test results and
further applications.

4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org