An Algorithm for Adaptive Determination of Radar Coherent Integration Time

Objective is a joint primary and secondary code (SC) acquisition estimator of tiered Global Navigation Satellite Systems (GNSS) signals. The estimator is based on the Parallel Code Search algorithm (PCS) combined with the Single-Block-Zero-Padding (SBZP) and the Pre-correlation Coherent Accumulation (PCA). The PCA realizes the extension of the coherent integration time in front of the PCS. However, the PCS with the SBZP and the PCA is affected by a navigation/SC bit transition problem due to its cyclic property of a computed Cross-Ambiguity Function (CAF). This CAF is degraded by diverse parasitic fragments and is not directly applicable for an acquisition. A novel analysis of this mechanism and its impact is presented. Then, the proposed modified SBZP (mSBZP) modified PCA (mPCA) PCS estimator is constructed, which does not degrade the CAF. The mSBZP allows the use of the PCS algorithm in the presence of SC bit transition, while the mPCA decreases the number of PCS algorithm calculations by a factor of SC chip count due to SC pre-correlation processing. The algorithm has the same detection performance in comparison with conventional Double-Block-Zero-Padding (DBZP). However, it allows using the PCS of half-length with longer latency up to a factor of SC chip count.

Download Full-text

Internal Waves' Role in Determining Probability Distribution of Coherent Integration Time Near 133 Hz and 3709 km in North Pacific Ocean

IEEE Journal of Oceanic Engineering ◽

10.1109/joe.2011.2167831 ◽

2011 ◽

Vol 36 (4) ◽

pp. 760-771 ◽

Cited By ~ 3

Author(s):

John L. Spiesberger

Keyword(s):

Pacific Ocean ◽

Probability Distribution ◽

Internal Waves ◽

North Pacific ◽

North Pacific Ocean ◽

Integration Time ◽

Coherent Integration ◽

Coherent Integration Time

Download Full-text

New waveform with both high range resolution and long coherent integration time in a HF radar

Proceedings of International Radar Conference ◽

10.1109/icr.1996.574443 ◽

2002 ◽

Cited By ~ 2

Author(s):

Shen Yiying ◽

Zhang Ning ◽

Liu Yongtan

Keyword(s):

Hf Radar ◽

Integration Time ◽

Range Resolution ◽

Coherent Integration ◽

Coherent Integration Time ◽

High Range

Download Full-text

Multiaircraft formation identification for narrowband coherent radar in a long coherent integration time

IEEE Transactions on Aerospace and Electronic Systems ◽

10.1109/taes.2015.140427 ◽

2015 ◽

Vol 51 (3) ◽

pp. 2121-2137 ◽

Cited By ~ 13

Author(s):

Shi-bao Peng ◽

Jia Xu ◽

Xiang-gen Xia ◽

Feng Liu ◽

Teng Long ◽

...

Keyword(s):

Integration Time ◽

Coherent Integration ◽

Coherent Integration Time ◽

Coherent Radar

Download Full-text

Improving the iGNSS-R Ocean Altimetric Precision Based on the Coherent Integration Time Optimization Model

Remote Sensing ◽

10.3390/rs13224715 ◽

2021 ◽

Vol 13 (22) ◽

pp. 4715

Author(s):

Xuezhi Sun ◽

Wei Zheng ◽

Fan Wu ◽

Zongqiang Liu

Keyword(s):

Optimization Model ◽

Sea Surface ◽

Integration Time ◽

Average Deviation ◽

Noise Interference ◽

Coherent Integration ◽

Time Optimization ◽

Ocean Altimetry ◽

Coherent Integration Time ◽

Along Track

Improving the altimetric precision under the requirement of ensuring the along-track resolution is of great significance to the application of iGNSS-R satellite ocean altimetry. The results obtained by using the empirical integration time need to be improved. Optimizing the integration time can suppress the noise interference from different sources to the greatest extent, thereby improving the altimetric precision. The inverse relationship between along-track resolution and signal integration time leads to the latter not being infinite. To obtain the optimal combination of integral parameters, this study first constructs an analytical model whose precision varies with coherent integration time. Second, the model is verified using airborne experimental data. The result shows that the average deviation between the model and the measured precision is about 0.16 m. The two are consistent. Third, we apply the model to obtain the optimal coherent integration time of the airborne experimental scenario. Compared with the empirical coherent integration parameters, the measured precision is improved by about 0.1 m. Fourth, the verified model is extrapolated to different spaceborne scenarios. Then, the optimal coherent integration time and the improvement of measured precision under various conditions are estimated. It was found that the optimal coherent integration time of the spaceborne scene is shorter than that of the airborne scene. Depending on the orbital altitude and the roughness of the sea surface, its value may also vary. Moreover, the model can significantly improve the precision for low signal-to-noise ratios. The coherent integration time optimization model proposed in this paper can enhance the altimetric precision. It would provide theoretical support for the signal optimization processing and sea surface height retrieval of iGNSS-R altimetry satellites with high precision and high along-track resolution in the future.

Download Full-text