Aerospace and Electronic Systems - March 2019 - 32

Feature Article:

DOI. No. 10.1109/MAES.2019.2901133

Mid-Sea and Land Based Wind Measurement for
Technology Demonstrator
S. Femina Beegum, R. Gopakumar, J. Girija, Vikram Sarabhai Space Centre,
Thiruvananthapuram, India

INTRODUCTION
Cost of access to space is always a concern which limits
space exploration and space utilization. The reusable
launch vehicle is an acceptable solution to achieve low
cost, reliable, and on-demand space access. India's reusable launch vehicle technology demonstrator hypersonic
experiment (RLV-TD HEX 01) [1] was the first of its kind
to demonstrate the hypersonic aero-thermo dynamic characterization of winged reentry body along with autonomous mission management to land at a specified location
[2]. The experiment was conducted from Indian launch
site at Satish Dhawan Space Centre Sriharikota (SDSC
SHAR) on May 23rd, 2016.
The wind load effect on any launch vehicle can be
reduced by suitable biasing of the vehicle steering
program, during its atmospheric phase of flight and
this process is referred as Wind Biasing (WB). Biasing
of the launch vehicle with the wind close to the time
of launch is referred as day of launch wind biasing
(DOL-WB). DOL WB ensures benign load conditions
during flight and it eliminates the risk of launch postponement due to unexpected wind conditions [3].
Efficient DOL WB requires wind measurements as
close to the time of launch as possible. Pisharoty sonde
system was used for wind measurement for the DOL
WB of RLV-TD HEX 01 mission.
Launch vehicles, such as polar satellite launch vehicle,
geosynchronous satellite launch vehicle, and launch vehicle mark 3, normally require wind data only from its
launch site (SDSC SHAR), for DOL WB as wind biasing

Authors' current address: S. Femina Beegum,
R. Gopakumar, J. Girija, RF Advanced Technology Division, Vikram Sarabhai Space Centre, Thiruvananthapuram
695022, India. E-mail: (s_feminabeegum@vssc.gov.in).
Manuscript received September 30, 2018; revised
December 13, 2018. ready for publication January 23,
2019.
Review handled by R. Sabatini.
0885/8985/19/$26.00 ß 2019 IEEE
32

is required only for lift-off phase. But RLV-TD required
atmospheric wind profiles for ascent phase DOL WB as
well as for the initialization of inertial navigation system
(INS) which is the key part of its autonomous navigation,
guidance, and control during its descent/landing phase [4].
Pisharoty sonde ascents for capturing ascent phase wind
profile were carried out from SDSC SHAR, while the
sonde ascents for descent phase wind were carried out
from a ship located at the Bay of Bengal, near to the
touchdown point.
A radiosonde is a balloon-borne instrument used
for the upper atmospheric studies typically up to
altitudes of 40 km [5]. It contains sensors capable of measuring atmospheric pressure, temperature, and humidity
(PTH). The Radiosonde is lifted up through the atmosphere by helium- or hydrogen-filled balloon. A transmitter located in the Radiosonde transmits the data to the
ground station. In conventional Radiosonde, the balloon is
tracked by radar to get the wind parameters at different
altitudes [6]. Radiosondes capable of measuring the position and the wind parameters with the help of global positioning system (GPS) receiver module, which is part of
the unit, in addition to the normal PTH parameters, are
generally called GPS sondes [7].
The fully end to end indigenous GPS sonde system
consisting of the balloon-borne sonde and corresponding ground station, designed and developed by RF Systems Group, Avionics, Vikram Sarabhai Space Centre,
Thiruvananthapuram is named as "Pisharoty sonde
system" after the famous Indian physicist and meteorologist Pisharoth Rama Pisharoty [8].

SYSTEM DESCRIPTION
Pisharoty sonde system consists of two subsystems,
namely, Pisharoty sonde and Pisharoty sonde ground station [8]. Schematic representation of Pisharoty sonde system is shown in Figure 1.
Pisharoty sonde consists of a GPS receiver module,
sensors, analog to digital converter (ADC), micro-

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MARCH 2019

Aerospace and Electronic Systems - March 2019

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