Validating the geometric accuracy of high spatial resolution multispectral satellite data

Figures & data

Figure 1. QuickBird pan-sharpened multispectral data encompassing the city of Nacogdoches, Texas, USA.

Figure 2. Visual collection of QuickBird-derived UTM coordinates versus GPS-derived UTM coordinates for traffic line number 8.

Table 1. Digitized and GPS-collected UTM easting and northing coordinates for all 33 traffic line locations within the city of Nacogdoches, TX, USA.

	Digitized point		GPS point
Point (ID)	Easting (m)	Northing (m)	Easting (m)	Northing (m)
1	340,482.00	3,501,020.00	340,476.88	3,501,022.52
2	341,204.00	3,500,910.00	341,198.02	3,500,907.29
3	340,436.00	3,501,310.00	340,431.02	3,501,311.25
4	345,075.00	3,502,870.00	345,070.73	3,502,868.49
5	345,685.00	3,502,660.00	345,681.72	3,502,665.76
6	342,331.00	3,502,350.00	342,327.66	3,502,349.38
7	343,088.00	3,502,370.00	343,083.59	3,502,367.71
8	340,773.00	3,503,180.00	340,766.89	3,503,182.38
9	343,158.00	3,501,600.00	343,152.70	3,501,600.08
10	344,439.00	3,500,890.00	344,434.70	3,500,890.26
11	344,528.00	3,501,530.00	344,521.57	3,501,522.50
12	346,548.00	3,502,040.00	346,543.51	3,502,044.02
13	346,912.00	3,500,450.00	346,905.31	3,500,449.69
14	344,871.00	3,499,330.00	344,865.98	3,499,322.19
15	344,168.00	3,497,840.00	344,163.67	3,497,836.65
16	346,685.00	3,498,170.00	346,681.84	3,498,169.79
17	346,278.00	3,497,190.00	346,275.20	3,497,187.00
18	344,738.00	3,496,890.00	344,735.82	3,496,887.67
19	344,680.00	3,496,920.00	344,677.27	3,496,920.94
20	343,872.00	3,495,020.00	343,870.40	3,495,015.45
21	343,692.00	3,495,010.00	343,690.66	3,495,010.67
22	341,569.00	3,494,700.00	341,567.36	3,494,695.86
23	342,430.00	3,496,980.00	342,419.66	3,496,985.33
24	341,963.00	3,496,390.00	341,960.84	3,496,391.50
25	342,011.00	3,496,400.00	342,009.27	3,496,401.27
26	340,706.00	3,495,630.00	340,703.08	3,495,624.85
27	340,672.00	3,495,370.00	340,670.96	3,495,371.99
28	341,868.00	3,498,000.00	341,865.23	3,498,003.31
29	342,569.00	3,498,520.00	342,564.67	3,498,512.40
30	343,534.00	3,498,670.00	343,530.14	3,498,665.83
31	343,854.00	3,499,420.00	343,848.44	3,499,415.02
32	345,569.00	3,498,370.00	345,566.35	3,498,375.32
33	345,775.00	3,502,080.00	345,771.50	3,502,076.73

Figure 3. Visual comparison of QuickBird-identified UTM location and GPS-identified UTM location.

Figure 4. Calculating the Euclidean distance between the on-screen digitized UTM coordinates and the GPS-derived UTM coordinates for traffic line number 8.

Table 2. The Euclidean distance between the purchased QuickBird UTM coordinates and the GPS-identified UTM coordinates for all 33 traffic line locations.

	Pixel location minus GPS location
Sample point(ID value)	Easting difference (m)	Northing difference (m)	Euclidean distance (m)
1	5.12	–2.52	5.71
2	5.98	2.71	6.57
3	4.98	–1.25	5.14
4	4.27	1.51	4.53
5	3.28	–5.76	6.63
6	3.34	0.62	3.40
7	4.41	2.29	4.97
8	6.11	–2.38	6.56
9	5.30	–0.08	5.30
10	4.30	–0.26	4.30
11	6.43	7.50	9.88
12	4.49	–4.02	6.03
13	6.69	0.31	6.69
14	5.02	7.81	9.28
15	4.33	3.35	5.47
16	3.16	0.21	3.17
17	2.80	3.00	4.10
18	2.18	2.33	3.19
19	2.73	–0.94	2.88
20	1.60	4.55	4.82
21	1.34	–0.67	1.50
22	1.64	4.14	4.45
23	10.34	–5.33	11.63
24	2.16	–1.50	2.63
25	1.73	–1.27	2.14
26	2.92	5.15	5.92
27	1.04	–1.99	2.25
28	2.77	–3.31	4.32
29	4.33	7.60	8.75
30	3.86	4.17	5.68
31	5.56	4.98	7.46
32	2.65	–5.32	5.94
33	3.50	3.27	4.79
Mean	3.95	0.88	5.34
Standard deviation	1.92	3.74	2.28

Table 3. Geometric accuracy statistics of the QuickBird image based on 33 traffic line locations.

	Mean error	Mean absolute error	RMSE	RSME
	(m)	(m)	(m)	(m)
Easting	3.95	3.95	4.38	3.95
Northing	0.88	3.09	3.79	0.88
Distance	5.34	5.34	5.79	4.05

Figure 5. Visual comparison of all 33 QuickBird-identified UTM traffic line coordinates with their corresponding GPS-collected UTM traffic line coordinates.