Power Transmission Tower Monitoring with Hydrostatic Leveling System: Measurement Refinement and Performance Evaluation

Table 4

Maximum, minimum, and final relative settlement values between the reference and monitoring points (cm) obtained by day-by-day (R1), monthly (R2), quarterly (R3), and annual (R4) processing schemes.

	Time
	0 : 00	6 : 00	12 : 00	18 : 00
Original result
Max	0.2	0.4	0.9	0.4
Min	−4.5	−3.3	−5.8	−4.7
Final	−3.5	−2.3	−3.5	−3.0
R1
Max	0.2	0.6	1.7	0.6
Min	−3.9	−3.3	−3.7	−2.8
Final	−3.2	−2.6	−3.1	−1.6
R2
Max	0.1	0.6	1.7	1.6
Min	−2.8	−1.4	−3.6	−1.6
Final	−2.5	−1.1	−2.3	1.0
R3
Max	0.2	0.5	1.4	0.7
Min	−1.8	−1.1	−3.4	−1.3
Final	−1.1	−0.7	−1.9	−0.5
R4
Max	0.1	0.4	1.9	0.7
Min	−4.3	−3.8	−3.7	−2.7
Final	−4.1	−3.1	−2.1	−2.0