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Suppression of an Effect of Terrain Unevenness on Accuracy of Height Measurement in UAV with Integrated Ultrasound Altimeter during Landing^{ †}

^{1}

^{2}

^{*}

^{†}

## Abstract

**:**

## 1. Introduction

## 2. Filtration Methods

_{e}(t) = [h

_{m}(t) + h

_{m}(t-1) + ∙∙∙ + h

_{m}(t-n)]/[n+1],

_{e}(t) is the height estimate at time t, h

_{m}(t) is a height measurement at time t, h

_{m}(t-1) is a height measurement at time t-1, h

_{m}(t-n) is a height measurement at time t-n, and n is the amount of past measurements used for the computation. In simulation in this paper, the number n = 9.

_{t|t-1}= A

_{t}x

_{t-1|t-1},

_{t|t-1}= A

_{t}P

_{t-1|t-1}A

_{t}

^{T}+ Q

_{t},

_{k|k-1}is a state vector prediction at time t computed from state vector estimate from time t-1 (x

_{t-1|t-1}), P

_{t|t-1}is a covariance matrix prediction at time t computed from covariance matrix of state at time t-1 (P

_{t-1|t-1}), Q

_{t}is a process noise covariation matrix and A

_{t}is a 2-by-2 transformation matrix defined as:

_{t}= [1 Δt, 0 1],

## 3. Simulation Scenarios

## 4. Evaluation of Simulation Results

## 5. Conclusions

## Acknowledgments

## References

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**Figure 2.**Simulation results of surface approximation by Kalman filter and moving average algorithm for defined surface profile 1 with no unevenness: (

**a**) using threshold detector; (

**b**) using intra-pulse phase signal modulation.

**Figure 3.**Simulation results of surface approximation by Kalman filter and moving average algorithm for defined surface profile 1 with small unevenness: (

**a**) using threshold detector; (

**b**) using intra-pulse phase signal modulation.

**Figure 4.**Simulation results of surface approximation by Kalman filter and moving average algorithm for defined surface profile 1 with large unevenness: (

**a**) using threshold detector; (

**b**) using intra-pulse phase signal modulation.

**Figure 5.**Simulation results of surface approximation by Kalman filter and moving average algorithm for defined surface profile 2 with no unevenness: (

**a**) using threshold detector; (

**b**) using intra-pulse phase signal modulation.

**Figure 6.**Simulation results of surface approximation by Kalman filter and moving average algorithm for defined surface profile 2 with small unevenness: (

**a**) using threshold detector; (

**b**) using intra-pulse phase signal modulation.

**Figure 7.**Simulation results of surface approximation by Kalman filter and moving average algorithm for defined surface profile 2 with large unevenness: (

**a**) using threshold detector; (

**b**) using intra-pulse phase signal modulation.

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**MDPI and ACS Style**

Dycka, P.; Janu, P.; Bajer, J.
Suppression of an Effect of Terrain Unevenness on Accuracy of Height Measurement in UAV with Integrated Ultrasound Altimeter during Landing. *Eng. Proc.* **2020**, *2*, 87.
https://doi.org/10.3390/ecsa-7-08263

**AMA Style**

Dycka P, Janu P, Bajer J.
Suppression of an Effect of Terrain Unevenness on Accuracy of Height Measurement in UAV with Integrated Ultrasound Altimeter during Landing. *Engineering Proceedings*. 2020; 2(1):87.
https://doi.org/10.3390/ecsa-7-08263

**Chicago/Turabian Style**

Dycka, Pavel, Premysl Janu, and Josef Bajer.
2020. "Suppression of an Effect of Terrain Unevenness on Accuracy of Height Measurement in UAV with Integrated Ultrasound Altimeter during Landing" *Engineering Proceedings* 2, no. 1: 87.
https://doi.org/10.3390/ecsa-7-08263