Thoth Technology Argus 2000 Owner's Manual
Argus 2000 IR Spectrometer
Owner’s Manual
Document Number
OG274001
© Thoth Technology, 2018. All rights reserved. This document is proprietary and should not be disseminated
without the written consent of Thoth Technology. The information contained in this document is restricted
and may be subject to international laws governing spacecraft products and services.
Thoth Technology Inc., Algonquin Radio Observatory, Achray Road, RR6
Pembroke, Ontario K8A 6W7, Canada
Tel: +(1) (905) 713-2884. Email: space@thothx.com, www.thothx.com
Issue
Release 1.03
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Table of Contents
1 PRODUCT KEY .................................................................................................... 5
2 PURPOSE ............................................................................................................ 6
3 SCOPE ................................................................................................................. 6
4 SYMBOLS USED ................................................................................................. 6
5 TRADEMARKS .................................................................................................... 6
6 IMPORTANT SAFETY INSTRUCTIONS .............................................................. 7
7 PACKAGE CONTENTS ....................................................................................... 7
8 PRODUCT FEATURES ........................................................................................ 8
8.1 Specifications ........................................................................................................... 9
8.2 Detector System ..................................................................................................... 10
8.3 Optical Design ....................................................................................................... 13
8.4 Optical Efficiency .................................................................................................. 13
8.5 Angular Sensitivity ................................................................................................. 14
8.6 Response to Collimated Monochromatic Laser Source ........................................ 15
8.7 Functional Design .................................................................................................. 15
8.8 Applications ........................................................................................................... 17
8.8.1 Observing atmospheric gas and mineral species ................................................................. 17
9 GROUND SYSTEM ELECTRONICS SETUP ..................................................... 22
10 ARGUS GSE TEST APPLICATION ................................................................... 22
10.1 Argus Status Message ............................................................................................ 23
10.2 Adjusting Spectrum Pixel Range ........................................................................... 23
10.3 Commanding the Instrument Settings .................................................................. 23
10.4 Data Logging ......................................................................................................... 24
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10.5 Communications .................................................................................................... 24
11 INTEGRATION ................................................................................................... 24
11.1 Power Interface ...................................................................................................... 24
11.2 Communications Interface .................................................................................... 24
11.3 Timing of Spectra Acquisition and Co-Adding Feature ....................................... 25
11.4 Data Packet Format ............................................................................................... 25
11.5 Connectors ............................................................................................................. 28
11.6 Mechanical Interfaces ............................................................................................ 30
11.7 Environment .......................................................................................................... 32
12 OPERATION ....................................................................................................... 33
12.1 Command Format (Models 01-03) ......................................................................... 33
12.1.2 Command List ......................................................................................................................... 35
12.2 Command Format (Model 04) ............................................................................... 37
12.2.2 Command List Model 04 ........................................................................................................ 40
13 TROUBLESHOOTING ........................................................................................ 43
14 WARRANTY ....................................................................................................... 43
14.1 Disclaimer .............................................................................................................. 44
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Release Notes
Issue Revisions Date
1.01
1.02
1.03
Draft for release.
Revised, corrected and enlarged
Revised
1 December 2017
16 March 2018
15 August 2018
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1 Product Key
The product code format for the Argus instruments described in this manual is:
ARGUS2000XYZ-NN.
The code descriptions are as follows:
Table 1: X Letter Code Key
Letter Code Description
A Aluminum optics
G Gold optics
S Space certified
N UAV grade
Table 2: Y Letter Code Key
Letter Code Description
U Unit only (kit excluded)
K Kit included
Table 3: Z Letter Code Key
Letter Code Description
L Standard range
E Extended range
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Table 4: NN Number Code Key
Number Code Description
01 700 nm – 1150 nm range
02 1000 nm –1650 nm range
03 1240 nm – 2000 nm extended range
04 1730 nm – 2200 nm extended range
2 Purpose
The purpose of this guide is to provide explanations and procedures for installing, operating,
maintaining and troubleshooting the Argus 2000 IR Spectrometer.
3 Scope
This document provides safety guidelines, setup information, operating instructions,
troubleshooting procedures and interface and technical specifications for the Argus 2000 IR
Spectrometer.
4 Symbols Used
The following symbols are used in this document.
CAUTION
!
instrument or other equipment.
Cautions identify conditions or practices that could result in damage to the
5 Trademarks
Argus is a registered trademark of Thoth Technology Inc.
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6 Important Safety Instructions
CAUTION
This guide contains important safety instructions that should be followed during
!
Before installing or using this product, read all instructions and cautionary markings located
in this guide.
The instrument should be handled with gloves in a suitable clean room environment. Care
should be taken not to contact optical surfaces or instrument corners.
Do not attempt to open or unseal the unit. This product contains no serviceable parts.
handling, installation and operation of this product. Be sure to read and understand
these safety instructions prior to handling.
The instrument shall be accommodated in a temperature and humidity controlled clean room
of cleanliness class no worse than 100,000 during handling, assembly, integration and test.
Anti-static grounding procedures must be observed when handling the instrument or
interface electronics. Care should be taken to align connector keys prior to insertion of
instrument interface.
Do not shock the instrument physically or expose this unit to liquids of any type.
7 Package Contents
The Argus instrument and GSE Kit includes the items shown in Figure 1 and itemized in
Table 5.
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Figure 1: Argus Instrument and GSE Kit.
Table 5: Argus GSE Kit Contents
Item Location (Figure 1) Description
1 Center Argus unit
2 Top left Shipping case
3 Top right Argus ground test display laptop
4 Bottom Left Argus power and communications interface
cable, example electrical and mechanical
mounting hardware.
5 Bottom Center Laptop serial interface USB adapter
6 Bottom Center Right Argus power USB adapter (5V)
7 Bottom Center Left Laptop power module
8 Bottom Right Laptop mains power cable (NEMA 5-15)
8 Product Features
The Argus spectrometer operates in the near infrared band in the standard range or in extended
range versions. For instrument spectral variations please see the product key. Argus features a
surface resolution of approximately 1.6 km when deployed in Low Earth Orbit (LEO). The
device uses a detector array of 1x256 elements that is actively cooled. Each pixel has a native
radiometric resolution of 10-bits. For models with numbers 01-03 resolution may be enhanced to
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13-bit performance by utilizing the integrations setting to co-add successive spectra. The device
includes a microcontroller, which controls the instrument’s components. The device operates
typically in a continuous single-pixel scanning mode with approximately 100 illuminated spectral
channels.
8.1 Specifications
The technical specifications for Argus 2000 are summarized in Table 6, below.
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Table 6: Technical Specifications, Argus 2000 Spectrometer
Argus 2000 Specification
1. Type Grating spectrometer
2. Configuration Single aperture spectrometer
3. Field of View 0.15º viewing angle around centered camera boresight with 15mm
fore-optics
4. Mass ~280 g
5. Accommodation 46 mm x 80 mm x 80 mm
6. Operating Temp. -20ºC to +40ºC operating temperature
7. Survival Temp. -25ºC to + 50ºC survival temperature
8. Detector InGaAs diode arrays with Peltier cooler
9. Grating 300 g/mm
10. Electronics microprocessor controlled 10-bit ADC (co-adding feature to enhance
precision to 13-bit, models 01-03), 3.6-4.2V input rail 250mA-1500mA
(375mA typical)
11. Operational Modes –Continuous cycle, constant integration time with co-adding feature
–Adaptive Exposure mode
12. Data Delivery Fixed length parity striped packets of single or co-added spectra with
sequence number, temperature, array temperature and operating
parameters
13. Interface Serial interface RS232 protocol
14. Spectral Channels 100 (typical)
15. Integration Time 500 μs to 4.096 sec
16. Handling Shipped by courier in ruggedized carrying case
8.2 Detector System
A linear gallium arsenide (InGaAs) photodiode array with high-quantum efficiency pixels in the
infrared detect radiation emitted for a 1.5 km2 surface tile, assuming LEO orbit altitude of 600
km, that has been divided spectrally by the grating optics. The array is a hybrid InGaAs and
CMOS acitve-pixel readout electronics in which the photo-current is buffered, amplified and
stored. Channels are differentially sampled as a form of double correlated sampling. Two values
of feedback capacitor may be selected (the HIGH setting enhances dynamic range, the LOW
setting increases sensitivity). Typical device quantum efficiencies are shown in the figures below.
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Figure 2: Detector Quantum Efficiency (1.7m device).
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Figure 3: Detector Quantum Efficiency (2.2 m device).
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Figure 4: Quantum efficiency of 2.6m detector measured at 20oC
8.3 Optical Design
The instrument is a single-scan pixel type observing a square surface tile and deriving
simultaneous independent measurements of the surface spectral emission. The fore optics
comprises a telescope lens system, field stop and mirror to provide a collimated image of the
surface tile onto the reflective grating. The reflective grating reflects a spectrally divided image (in
the vertical plane) onto another mirror that focuses the first spectral order of the surface tile
image onto the detector. The particular optical configuration is determined by Thoth’s custom
design tool. Spectrometers may be customized for particular spectral ranges or resolution by
choice of grating type and optical element placement.
8.4 Optical Efficiency
The typical optical efficiency of Argus is shown in Figure 5 as a function of wavelength against a
NIST traceable source. The variation arises because of the device’s approximately constant
quantum efficiency over this wavelength range. Argus instruments require assembly to high
tolerances and are individually tuned to optimize performance. Consequently, the absolute
radiometric calibration will vary from instrument to instrument. Instruments can be ground
calibrated for absolute radiance by using a calibrated light source viewed from a range of at least
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12 meters and a 5 Degree of Freedom (DOF) kinematic mount. However, it is our experience is
that due to alignment difficulties and variation between test lamps and solar insolation that results
are only accurate to approximately 10%. Characteristic space radiance data is given in section
8.8.1.
-7
Calibration Results us ing Datafile: l ampCanXP rocData.log
x 10
6
5.5
5
4.5
Joules per Count
4
3.5
3
1.2 1.3 1.4 1. 5 1.6 1.7
Wavelength
x 10
-6
Figure 5: Spectrometer Energy Conversion Efficiency (1.6 ms exposure) against
NIST traceable standard screen and source (typical results).
8.5 Angular Sensitivity
The angular sensitivity in response to a 1523 nm collimated gas laser is shown in Figure 6 for the
standard grade Argus instrument. The full-width-half-maximum is estimated at 0.15o. At a typical
LEO orbital height of 600 km, this corresponds to a surface tile of length 1.57 km.
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