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HABLAN-users-manual

HABLAN - Multispectral and Multiangular Remote Sensing of the Light at Night from High Altitude Balloon

User's Manual

Martin Aubé^{1, 2}, Ph.D. (PI)

autres auteurs¹

¹ Cégep de Sherbrooke, Sherbrooke, Québec, Canada

² Université de Sherbrooke, Sherbrooke, Québec, Canada

Img:hablan.jpg Δ

March 8, 2019

<a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/"><img alt="Creative Commons License" style="border-width:0" src="license" href="http://creativecommons.org/licenses/by-sa/4.0/">Creative Commons Attribution-ShareAlike 4.0 International License</a>.

Abstract

In collaboration with the Canadian Space Agency (CSA) and the European Space Agency (ESA) in the framework of the STRATOS project, we will launch a dual DSLR system to observe the multiangular and spectral properties of the installed luminaires from an altitude of 36 km. STRATOS project consists of high altitude balloon flights to perform a variety of near space experiments. Two Sony A7S cameras will be attached to a gimbal in order to assure a nadir pointing stability. The balloon will take off at Timmins (ON, Canada), and will land near Val d’Or (QC, Canada), going over Rouyn-Noranda (QC, Canada). The experiment will take place around the new moon of August 2019. One of the two cameras is equipped with a 50mm lens, assuring the collection of high-resolution images (6 m per pixel). Data, such as multispectral radiance of light points and spectral type recognition, ground cover, and obstacles properties will be derived from this camera. The other camera is equipped with an 8mm fisheye lens so that the angular function of the luminaires will be sampled up to almost 90-degrees from zenith. Close to the flight, ground-based data will be acquired. For instance, we will use the LANcube multiangular and multispectral sensor in a roadrunner mode to map the light at night all over the overflown region. We will also sample the sky brightness with a third A7S camera equipped with a fisheye lens.

Hardware

Components

The system consists of the following items:

Item #	Component name	Number	Picture
1	Raspberry pi model 3 B+	1
2	SanDisk Ultra 256GB micro SDHC Card	1
3	SanDisk 256GB Ultra Fit	1
4	USB GPS tratux Vk-162 Remote Mount USB GPS (U-blox)	1
5	Real time clock breakout DS3231 & CR 2032 battery	1
6	Sony A7S DSLR	2
7	8 mm Samyang manual focus lens - T3.8 UMC Fish-Eye CS II Lens for Sony E Mount (model SYHD8MV-NEX)	1
8	50 mm Samyang manual focus lens -T1.5 VDSLR AS UMC Lens for Sony E Mount (model SYDS50M-NEX)	1
9	AC-PW20 Fully Decoded DC Coupler dummy battery	2
10	micro usb male soldering connector - to power the raspbery pi	1
11	USB-A female soldering connector	2
12	Speedbag swivel	1
13	12mm/0.47" Dia Shaft Coupling Motor Connector Steel Universal Joint	1
14	5/16in 1 1/2in hex bolt	2
15	5/16in coupling nut	1
16	Mat black spray paint - to apply inside the insulated enclosure	-
17	Mat white spray paint - to apply outside the insulated enclosure	-
18	1/4-20 1/2in screws	2
19	1/8in Aluminium U channel w=2in h=1 1/2in x 2 in long	1
20	6in x 6in x 1/16in aluminium plate	1
21	1/16in aluminium z bar
22	1/8in aluminium channel 1 1/2in x 1 1/2in
23	1/16in aluminium corner 1 1/2in
23	Aluminium pop rivet
24	1in thick aluminium foil bounded insulation panel

Mechanical components

Aluminium structure

Mass:

Insolated box and back face

Mass:

Optical components

Computer

Wiring

Pinout informations and GPIO pinout map

RPI GPIO pinout map

RPI microUSB power pinout

Real time clock wiring

We are using the DS3231 RTC module to keep the date and time after powering off the system.

The RTC pins should follow the following configuration

The pin numbers below refers to figure "RPI GPIO pinout map".

• VCC connects to Pin 1
• SDA connects to Pin 3
• SCL connects to Pin 5
• GND connects to Pin 6

Shutdown button

The shutdown button should follow the following configuration

The pin numbers below refers to figure "RPI GPIO pinout map".

• 1 wire connects to Pin 13 (GPIO 27)
• the other wire connects to Pin 14 (GND)

The RPI will reboot if the button is held for more than two seconds but fewer than five seconds and it will shut down if the button is held for more than five seconds.

Assembly

Setting up the HABLAN for measurements

Access to the data

Data format

The data is structured in the following way.

Shutdown of the HABLAN

Press the shutdown button at least 5 seconds.

Reboot of the HABLAN

Press the shutdown button 3 seconds.