By

Isaac Kuma Yeboah

and

Mohammed N.A Daanaahttp://www.sssri.edu.gh

Exploring the Beauty of deep space

Table of Contents

� Background

� Mission Objectives

� Operation Concept

----Space segment

--- Ground segment

� Technical risks

� Uniqueness

� Implementation Schedule

� Costs

� Collaboration

Background� Many people around the world living in communities near water bodies which serve as

a source of generating income, nourishment and livelihood.

� Yet these communities are prone to dangers such as flooding and drought, a few of such communities include those along the Volta basin which extends from Ghana to Burkina Faso, Togo, Ivory Coast, Mali and Benin as shown in figures 1 and 2 .

� Recently in Ghana the Volta Lake flooded and destroyed some communities along its bank as shown in figure 3 , the same lake suffered from a drought in 1970.

� Unfortunately the communities around the Waija Lake near greater Accra are at the mercy to the same sort of danger like the people of Volta Lake communities are facing.

� On the 3rd of June 2015 a downpour flooded most of Accra and neighboring areas, these floods caused explosions at some petrol filling stations and over 200 lives were lost.

Proposed Solution To The Problem.

� Satellite System is the best methodof solving our problem becauseunfortunately other wirelesstelecommunication systems such asmobile network signals are veryweak and unreliable in areas such asVolta and some parts of Accra

� The Mobile network signal is weakat the Volta lake and is a flood-prone area this houses the Akosobodam and Hydroelectric powerstation.

� Waija lake which is part of Accra isone of the flood-prone area thishave the biggest water processingdam and station which providedportable water to the whole ofGreater Accra and same part ofCentral Region.

Mission Objectives� To develop a system to monitor water level of Volta Lake and

communicate with satellite constellation we need to follow the steps below.

� Construction of a water monitoring systems based on solar power, a microcontroller interfaced with an ultrasonic sensor to measure at any giving time the water level using UHF satellite transmitter.

� Construction of a ground station located in Accra Ghana, consisting of a VHF receiver, a computer and a mobile Phone.

� Construction of three low earth orbit satellites less than 5 kg each, since each would only carry on board computers , Transceivers, Telemetry systems that will enable communication with the water level system and ground station

� These will help the Environmental protection agency(EPA), National deserter mobilization organization(NADMO) and the Volta basin authority (VBA)conduct studies and analysis on the causes of flooding , drought and deserter.

Operation Concept� The water level monitoring systems on the ground located

at Volta Lake and Waija Lake are based on a solar powered Microcontroller for self-sustainability, interfaced with an Ultrasonic sensor fixed at a specified distance of about 2 meters from the water in order to determine the level of the water at any giving time and a UHF transmitter to uplink water level measurement data to the Nanosat constellation.

� The Nanosat constellation consisting of 3 Nanosat downlinks water level measurement data to a Ground station via VHF transceiver located in Accra Ghana or any other place and data is recorded in a computer. Commands can be sent to the Nanosat constellation from the ground station on VHF.

Operational Concept

Ground segmentWater monitoring station #1 and #2

Lake depth = Ullage – Fillage, where Ullage is the fixed length between the sensor and the water surface while the Fillage is the distance between the water surface and then Lake Floor

Narrow beam with high sensitive sensors of repetition rate up to 100Hz.

The Ultrasonic Water Level Monitoring Systems.

�

Ground Tracking and Nano-satellites Pointing in Ghana.Satellite tracking involves pointing an antenna located on the river Volta and Wajia lake located on the ground at a satellite and following its position in its orbit.

Ground track is the path of the subsatellite point on the Earth‘s surface. The coverage area of a single satellite is give by where Re is the radius of the earth and θ is the earth central angle.

The earth central angle θ is calculated using , where E is the minimum elevation angle and h is the satellite altitude

The nanosat constellation coverage area is calculated as A = 255,592,9663 km², with earth central angle of θ = 1.934º. The equatorial radius of the earth is 6378km. The satellite altitude is 400km, and minimum elevation angle of antenna beam width of 60º.

Space SegmentThe Nano sat communicates to the ground station and the water monitoring station using UHF and VHF, the Accelerometer is a 3 axis which would help determine the orientation of our Nanosat, the GPS would enable us to know the satellite position over the earth, Momentum based 3-axis stabilization are used to maintain altitude.

NanoSat #1 ,#2 and #3 OBC High performance, low power 32-bit ARM Cortex-M3 based MCU 4-48MHz

@ 1.25 DMPIS/MHz Integrated Internal Real-Time-Clock 4MB of Flash for Code Storage 2 x 1 MB of external SRAM for Data Storage and a Micro SD socket for storage up to 2GB of data with built in GPS and accelerometer modules

Orbit Apogee of 400 km and in order to cover Both Accra and Brisbane an inclination of less than 28 degrees will be adequate for coverage of both cities and 35 degrees inclination for Canberra.

Altitude control system

and propulsion

Momentum based 3-axis stabilization

Communication Power: <1.7W (transmitter on), <0.2W (receiver only)Downlink data rate: 1200, 2400, 4800 or 9600 bpsUplink data rate: 300 or 1200 bps

Power Cells providing up to 30W of power per panel Power generation: max average 80W~ 90W with 3 panelsPower consumption: average 50 WBus voltage: 12v,5VBattery: 5.8AH Li-Ion

Space Segment

Space Segment

Link Budgeting

At frequency of 430MHz for UHF and 140MHz for VHF, transmitting power at 1.8w, Distance of 2294 km, 30° elevation

VHF Uplink UHF Downlink

Frequency[Ghz] 0.14 0.43

Transmitter power[w]

1.8 1

Transmitter AntennaeGain[dB]

20 0

Receiver antennae Gain[dB]

0 20

Space losses [dB] -140.87 -150.37

Orbit Description

Space Segment

RisksThere exist possible risks such as

1)Component failure after launch.

2) In-lab equipment failure.

3)Communication system failure.

4)Missed deadlines.

5)Loss of expertise

Expected Results� The success of this project will be to the benefit of the

people of Ghana and the various nations sharing the Volta basin tributaries, by getting better prepared for the flooding, droughts and decide on the necessary actions to protect and preserve the water bodies.

� The difficulties in learning the use of satellite data for flood assessment, flood prediction and flood management have been solved by using Nanosat.

� This will help authorities and insurances in the precise assessment of the damaged area and in planning and organizing support for reconstruction by authorities.

Uniqueness� Similar to the Utilizing Nano Satellites for Water Monitoring

for Nile River, yet unique in the sense that It is the first time a satellite mission is designed in Ghana that would encourage more African nations to make a step forward in considering miniature satellite technology as a platform to solve their issues locally already our system would serve about 5 or more countries within the sub region.

� Narrow ultrasound beam, high sensitive sensors for distance measurement also at steep, small and fast waves with high resolution and accuracy.

� Free of calibration due to synchronization of sensors and high repetition rate up to 100Hz for measuring of wave contours up to breaking wave.

Implementation Schedule

� The construction of the NanoSat will be largely done by internship students under supervision in the laboratory of the Space Science Systems and Research Institute.

Final prototype design 2016

Flight model 2017

Monitoring station Construction 2015

Launching of Nanosat Depends on launching operators

Cost estimations

Item Cost($) Notes

3 Nano Satellite 22,000 With further development

2 monitoring stations 4,000 Test and further development

Ground station 10,000

Launching ~80,000 Depends on the date

5 years operation 100,000 To be managed by SSSRI

Total 213,000

CollaborationsThe SSSRI will collaborate with University of New South Wales Canberra as our local collaborator ,Ghana space science and technology ,the Multinational Authority which comprises of Benin-Burkina Faso-Côte d'Ivoire-Ghana-Mali-Togo and Miyazaki laboratory in Japan as our foreign partner in achieving our said targets.