Automatic aircraft avoidance for laser uplink safety

Meenehan, Seán M.; Dunkel, Emily; Cheng, Michael

doi:10.1117/12.2607303

Cited by 7 publications

(3 citation statements)

References 28 publications

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“…Alternately, square wave modulation (50% duty cycle) with no uplink data is possible. Outdoor laser safety measures [16] are implemented by an Uplink Laser Safety Assembly (ULSA).…”

Section: Ground Laser Transmitter (Glt)mentioning

confidence: 99%

Deep space optical communications technology demonstration

Biswas,

Srinivasan,

Andrews

et al. 2024

Free-Space Laser Communications XXXVI

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The National Aeronautics and Space Administration's (NASA) Deep Space Optical Communications (DSOC) payload, launched with the Psyche spacecraft on October 13, 2023, is facilitating an ongoing technology demonstration (TD) of free-space optical communications (FSOC), from beyond the earth-moon system. The DSOC flight laser transceiver (FLT), can acquire a 1064 nm uplink laser from earth, and return a 1550 nm, serially concatenated pulse position modulated (SCPPM) signal, to earth. The FLT uses a 22 cm diameter unobscured optical transceiver assembly, coupled to a 4 W average power laser transmitter, supplemented with actuators, sensors, electronics and software. A 5-7 kW average power, multi-beam 1064 nm uplink laser assembly integrated to the Optical Communications Telescope Laboratory (OCTL) near Wrightwood, CA serves as the Ground Laser Transmitter (GLT). The DSOC Ground Laser Receiver (GLR) at the Palomar Observatory, Hale telescope (operated by Caltech Optical Observatories), consists of a superconducting nanowire single photon detector (SNSPD) array, connected to a ground signal processing assembly. Signal photon arrivals are detected and processed to extract information codewords at the GLR. A Mission Operations System (MOS) co-located with the Psyche Project Mission Operations Center, at the Jet Propulsion Laboratory (JPL), coordinates DSOC technology demonstration activities. This paper presents a system overview, mission description and operations architecture for the TD. Early results that include downlink at maximum downlink data-rate of 267 Mb/s from 0.37 astronomical units (AU) or 55 million kilometers are presented.

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“…Alternately, square wave modulation (50% duty cycle) with no uplink data is possible. Outdoor laser safety measures [16] are implemented by an Uplink Laser Safety Assembly (ULSA).…”

Section: Ground Laser Transmitter (Glt)mentioning

confidence: 99%

Deep space optical communications technology demonstration

Biswas,

Srinivasan,

Andrews

et al. 2024

Free-Space Laser Communications XXXVI

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“…The DSOC TD was facilitated by NASA's Psyche Mission [5] hosting the flight payload and allocating weekly contact opportunities during the first 2 years of the long 6-year cruise. Ground station constraints, for example, nighttime only at GLR, and uplink laser safety [6] sensors restricted to minimum sun-earth-probe (SEP) angle of 35 are factored into TD opportunities. Figure 2a shows the Psyche spacecraft trajectory where the blue dots indicate DSOC optical link opportunities.…”

Section: Mission Summarymentioning

confidence: 99%

Photon-counting for deep space optical communications

Biswas,

Srinivasan,

Wollman

et al. 2024

Advanced Photon Counting Techniques XVIII

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Motivated by the need for higher data volume return from NASA's future planetary missions, the deep space optical communications (DSOC) technology demonstration (TD) was initiated. The DSOC project integrated a flight laser transceiver to the Psyche Mission spacecraft which launched on Oct. 13, 2023. Ground transmitting and receiving stations implemented by instrumenting existing assets, make more or less weekly optical links with the receding spacecraft. Compared to past and ongoing free-space optical communication (FSOC) TD's, the key difference for DSOC, is the huge increase in link distance. Photon-counting at both ends of the link were mandated to overcome the link difficulty, defined as data-rate times link-distance squared. In this paper a summary of the photon-counting applications and experience gained so far will be described.

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“…The first tier of the external laser safety system consists of a narrow field-of-view (17.6°) and a wide field-of-view (50°) thermal camera aligned to the telescope boresight, intended to detect aircraft within 20 km of the GLT that may not be captured by the FAA NextGen data, along with two sets of visible and fisheye roof-mounted camera to capture low-flying fast-moving aircraft. ULSA algorithms and software developed entirely in-house 12 are used to process the thermal camera images. These algorithms track and classify objects, and then automatically shutter the uplink lasers if an object is classified as an aircraft that is predicted to enter the beam.…”

Section: Uplink Laser Safety Assembly (Ulsa)mentioning

confidence: 99%

The Deep Space Optical Communications project ground laser transmitter

Srinivasan

Velasco

Wright

et al. 2023

Free-Space Laser Communications XXXV

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The Deep Space Optical Communication (DSOC) project will conduct its technology demonstration concurrently with NASA's Psyche mission, which hosts the DSOC flight transceiver (FLT) on its spacecraft and will operate it over an approximate range of 0.05 to 3.0 AU. The DSOC Ground Laser Transmitter (GLT), located at the Jet Propulsion Laboratory's Optical Communication Telescope Laboratory (OCTL) near Wrightwood, CA, has been developed to provide a high-power optical uplink beacon that serves as a line-of-sight FLT downlink pointing reference and delivers low rate (1.8 kbps) uplink command data to the FLT. In this paper we present an overview of the completed GLT and its subsystems: (i) the multi-beam Uplink Laser Assembly (ULA) capable of transmitting up to 7 kW of average power, (ii) the Uplink Data Formatter that modulates the ULA, (iii) the GLT Optics Assembly that manages the ULA high power output beams and couples them to the OCTL telescope, (iv) the Uplink Laser Safety Assembly that automatically avoids hazardous laser irradiation by shuttering the laser output, and (v) the custom-developed Monitor and Control software used to test and operate the entire system. We discuss various implementation and operational challenges, and review results from key system performance verification and operational tests, indicating the readiness of the Ground Laser Transmitter station to fulfill the DSOC technology demonstration objectives.

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Automatic aircraft avoidance for laser uplink safety

Cited by 7 publications

References 28 publications

Deep space optical communications technology demonstration

Deep space optical communications technology demonstration

Photon-counting for deep space optical communications

The Deep Space Optical Communications project ground laser transmitter

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