# Tracking Multiple Unmanned Aerial Vehicles through Occlusion in Low-Altitude Airspace

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## Abstract

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## 1. Introduction

## 2. Problem Discussion

#### 2.1. Markov-Chain Model of Target Existence

#### 2.2. Sensor Measurement Model

## 3. Integration of LMIPDA and MC2 (LMIPDA-MC2)

## 4. False-Track Discrimination (FTD)

## 5. Illustrative Simulation and Experimental Results

#### 5.1. Monte Carlo Simulation Results

- Case: to obtain the total number of confirmed track pursuing the original $\tau \mathrm{th}$ target in scan $k=13$.
- Okay: to obtain the total number of CTTs that still retain the original $\tau \mathrm{th}$ target in scan $k=28$.
- Switched: to obtain the total number of CTTs that switched the original target to some other CTT and now pursue a different target in scan $k=28$.
- Lost: to obtain the total number of CTTs that were lost in scan $k=28$ because they were either terminated or they became CFTs.
- End: to obtain the total number of CTTs at the end scan $k=36$.
- Execution time [s]: the average execution time per run.

^{TM}i7-1165G7 (@ 2.80 GHz, 2.80 GHz) computer for programming the algorithms.

#### 5.2. Experimental Results

## 6. Conclusions

## Author Contributions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 1.**The flowchart of the LMIPDA-MC2 method [30].

**Figure 5.**Root mean square errors (RMSEs). (

**a**) RMSE of Target 1. (

**b**) RMSE of Target 2. (

**c**) RMSE of Target 3.

**Figure 6.**Experimental platform: (

**a**–

**c**) are reprinted from Expert Systems with Applications, 177, Myunggun Kim, Sufyan Ali Memon, et al., Dynamic based trajectory estimation and tracking in an uncertain environment, Page No. 7, Copyright (2021), with permission from Elsevier. (

**a**) Surveillance region. (

**b**) UAV. (

**c**) Autonomous vehicle. (

**d**) Experimental setup.

**Figure 7.**Tracking and estimation of each target trajectory: The original position of all autonomous vehicle (depicted by dashed colored lines) are reprinted from Expert Systems with Applications, 177, Myunggun Kim, Sufyan Ali Memon, et al., Dynamic based trajectory estimation and tracking in an uncertain environment, Page No. 8, Copyright (2021), with permission from Elsevier. (

**a**) LMIPDA-MC2. (

**b**) LMIPDA-MC1.

**Figure 8.**Position estimation of targets using LMIPDA−MC2. (

**a**) UAV. (

**b**) Autonomous vehicle 1. (

**c**) Autonomous vehicle 2. (

**d**) Autonomous vehicle 3.

**Figure 9.**Position estimation of targets using LMIPDA−MC1. (

**a**) UAV. (

**b**) Autonomous vehicle 1. (

**c**) Autonomous vehicle 2. (

**d**) Autonomous vehicle 3.

Algorithm | Case | Okay | Switched | Lost | End | time [s] |
---|---|---|---|---|---|---|

IPDA-MC1 | 517 | 449 | 38 | 30 | 574 | 0.3 |

IPDA-MC2 | 513 | 422 | 56 | 35 | 561 | 0.4 |

LMIPDA-MC1 | 568 | 550 | 16 | 2 | 595 | 0.2 |

LMIPDA-MC2 | 600 | 598 | 2 | 0 | 599 | 0.5 |

Parameter | Description | Value |
---|---|---|

$\mathbf{A}$ | Surveillance region | ${[3,4,4]}^{\mathrm{t}}\phantom{\rule{0.166667em}{0ex}}\mathrm{m}$ |

${\mathit{R}}_{k}$ | Measurement noise covariance | $0.08{\mathbf{I}}_{3\times 3}$ |

Number of scans | Number of time steps | 83 |

T | Sampling time between scans | $0.25\phantom{\rule{0.166667em}{0ex}}\mathrm{s}$ |

${P}_{D}$ | Detection probability | $0.8$ |

${\rho}_{k,i}^{\tau}$ | Clutter measurement density | $5\times {10}^{-4}\phantom{\rule{0.166667em}{0ex}}{\mathrm{m}}^{-3}$ |

$\alpha $ | Validation measurement-selection threshold | 5 |

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## Share and Cite

**MDPI and ACS Style**

Memon, S.A.; Son, H.; Kim, W.-G.; Khan, A.M.; Shahzad, M.; Khan, U.
Tracking Multiple Unmanned Aerial Vehicles through Occlusion in Low-Altitude Airspace. *Drones* **2023**, *7*, 241.
https://doi.org/10.3390/drones7040241

**AMA Style**

Memon SA, Son H, Kim W-G, Khan AM, Shahzad M, Khan U.
Tracking Multiple Unmanned Aerial Vehicles through Occlusion in Low-Altitude Airspace. *Drones*. 2023; 7(4):241.
https://doi.org/10.3390/drones7040241

**Chicago/Turabian Style**

Memon, Sufyan Ali, Hungsun Son, Wan-Gu Kim, Abdul Manan Khan, Mohsin Shahzad, and Uzair Khan.
2023. "Tracking Multiple Unmanned Aerial Vehicles through Occlusion in Low-Altitude Airspace" *Drones* 7, no. 4: 241.
https://doi.org/10.3390/drones7040241