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A function to calculate the dynamic brownian motion variance for a movement track. It can be also used by advanced programmers to program against.

Usage

# S4 method for .MoveTrackSingle,numeric,numeric,numeric
brownian.motion.variance.dyn(object, location.error, window.size, margin)

Arguments

object

a move, moveStack or moveBurst object can be used for variance calculation. This object must be in a flat coordinate system (projection different to longitude/latitude), use spTransform to transform your coordinates.

location.error

single numeric value or vector of the length of coordinates that describes the error of the location (sender/receiver) system in map units.

window.size

The size of the moving window along the track for the variance calculation. Larger windows provide more stable/accurate estimates of the brownian motion variance but are less well able to capture more frequent changes in behavior. This number has to be odd.

margin

The margin size used for variance calculation. This number has to be odd.

Value

'dBMvariance' object, if move object is provided

'dBMvarianceStack' object, if moveStack object is provided

'dBMvarianceBurst' object, if moveBurst object is provided

References

Kranstauber, B., Kays, R., LaPoint, S. D., Wikelski, M. and Safi, K. (2012), A dynamic Brownian bridge movement model to estimate utilization distributions for heterogeneous animal movement. Journal of Animal Ecology. doi: 10.1111/j.1365-2656.2012.01955.x

Author

Bart Kranstauber & Anne Scharf

See also

brownian.bridge.dyn, linkdynBGBvariance

Examples

data(leroy)
data2 <- spTransform(leroy[1:80,], CRSobj="+proj=aeqd +ellps=WGS84", center=TRUE)
err<-rep(23.5,n.locs(data2))
dBMvar <- brownian.motion.variance.dyn(data2, location.error=err, margin=13, window.siz=31)
dBMvar
#>               coordinates               timestamp eobs.battery.voltage
#> 45  (-2073.424, 1090.731) 2009-02-11 12:16:45.000                 3615
#> 46  (-2067.168, 1089.462) 2009-02-11 12:31:38.000                 3623
#> 47  (-2065.016, 1084.285) 2009-02-11 12:45:48.997                 3627
#> 48  (-2059.363, 1095.625) 2009-02-11 13:00:16.002                 3632
#> 49  (-2066.399, 1089.018) 2009-02-11 13:15:19.000                 3642
#> 50  (-2077.535, 1085.322) 2009-02-11 13:30:13.000                 3647
#> 51  (-2064.253, 1089.517) 2009-02-11 13:45:37.000                 3652
#> 52  (-2064.594, 1072.254) 2009-02-11 14:00:35.000                 3647
#> 53  (-2066.818, 1082.508) 2009-02-11 14:15:49.000                 3652
#> 54  (-2067.694, 1083.808) 2009-02-11 14:30:49.000                 3654
#> 55  (-2062.493, 1089.228) 2009-02-11 14:45:13.997                 3653
#> 56  (-2062.828, 1090.483) 2009-02-11 15:00:45.000                 3666
#> 57  (-2067.478, 1065.723) 2009-02-11 15:15:10.999                 3623
#> 58   (-2065.26, 1091.861) 2009-02-11 15:30:44.999                 3652
#> 59  (-2074.312, 1103.728) 2009-02-11 15:45:33.000                 3657
#> 60  (-2060.905, 1115.577) 2009-02-11 16:00:31.999                 3654
#> 61  (-2067.577, 1091.906) 2009-02-11 16:15:14.999                 3654
#> 62  (-2070.509, 1090.119) 2009-02-11 16:30:11.000                 3662
#> 63  (-2066.077, 1096.916) 2009-02-11 16:45:52.999                 3666
#> 64  (-2069.845, 1092.751) 2009-02-11 17:00:12.000                 3653
#> 65    (-2053.83, 1062.02) 2009-02-11 17:15:12.997                 3662
#> 66  (-2060.667, 1091.182) 2009-02-11 17:30:19.000                 3662
#> 67   (-2059.831, 1091.16) 2009-02-11 17:45:45.000                 3663
#> 68  (-2069.157, 1093.051) 2009-02-11 18:00:23.000                 3662
#> 69  (-2066.703, 1084.774) 2009-02-11 18:15:19.999                 3657
#> 70   (-2071.263, 1085.62) 2009-02-11 18:30:09.999                 3662
#> 71  (-2069.618, 1085.953) 2009-02-11 18:45:17.997                 3664
#> 72  (-2070.196, 1094.807) 2009-02-11 19:00:12.997                 3664
#> 73  (-2070.331, 1082.032) 2009-02-11 19:15:14.997                 3664
#> 74  (-2066.732, 1069.811) 2009-02-11 19:30:48.000                 3662
#> 75  (-2069.779, 1094.795) 2009-02-11 19:45:23.997                 3657
#> 76  (-2056.311, 1090.726) 2009-02-11 20:01:20.997                 3658
#> 77  (-2075.635, 1061.349) 2009-02-11 20:15:44.999                 3647
#> 78    (-2070.6, 1085.709) 2009-02-11 20:30:22.000                 3652
#> 79  (-2070.945, 1083.209) 2009-02-11 20:45:14.000                 3657
#> 80  (-2072.785, 1090.986) 2009-02-11 21:00:17.999                 3666
#> 81  (-2056.526, 1082.972) 2009-02-11 21:15:18.999                 3664
#> 82  (-2059.877, 1076.652) 2009-02-11 21:30:16.999                 3652
#> 83  (-2074.422, 1092.175) 2009-02-11 21:45:06.000                 3657
#> 84  (-2065.179, 1088.118) 2009-02-11 22:00:23.000                 3662
#> 85  (-2067.703, 1082.786) 2009-02-11 22:15:15.000                 3657
#> 86  (-2071.958, 1088.931) 2009-02-11 22:30:49.000                 3657
#> 87  (-2070.336, 1092.196) 2009-02-11 22:45:23.000                 3652
#> 88  (-2079.595, 1071.314) 2009-02-11 23:00:19.999                 3657
#> 89  (-2069.619, 1081.587) 2009-02-11 23:15:15.997                 3652
#> 90   (-2067.146, 1080.82) 2009-02-11 23:30:26.000                 3662
#> 91  (-2067.079, 1088.185) 2009-02-11 23:45:09.000                 3653
#> 92   (-2063.41, 1088.695) 2009-02-12 00:00:05.999                 3657
#> 93  (-2069.888, 1085.942) 2009-02-12 00:15:38.997                 3662
#> 94   (-2061.815, 1084.54) 2009-02-12 00:30:39.000                 3652
#> 95  (-2070.337, 1062.247) 2009-02-12 00:45:19.997                 3647
#> 96  (-2071.609, 1080.432) 2009-02-12 01:00:11.997                 3652
#> 97  (-2065.697, 1080.264) 2009-02-12 01:15:09.997                 3653
#> 98  (-2068.775, 1081.753) 2009-02-12 01:30:22.000                 3662
#> 99  (-2069.954, 1085.175) 2009-02-12 01:45:12.000                 3653
#> 100 (-2084.331, 1085.824) 2009-02-12 02:00:08.997                 3652
#> 101 (-1739.362, 1265.913) 2009-02-12 02:15:30.000                 3648
#> 102 (-1545.267, 1254.003) 2009-02-12 02:30:13.999                 3632
#> 103 (-1355.856, 1236.466) 2009-02-12 02:45:58.999                 3637
#> 104 (-671.8046, 1477.927) 2009-02-12 03:01:11.000                 3623
#> 128 (-254.3866, 1629.167) 2009-02-12 09:30:55.000                 3615
#> 129 (-197.2929, 1763.915) 2009-02-12 09:45:31.000                 3623
#> 130 (-255.5174, 1604.061) 2009-02-12 10:00:18.000                 3632
#> 131 (-254.6976, 1633.055) 2009-02-12 10:15:55.999                 3640
#> 132  (-233.058, 1652.828) 2009-02-12 10:30:55.997                 3638
#> 133    (-243.98, 1645.03) 2009-02-12 10:45:52.000                 3642
#> 134 (-254.4599, 1638.909) 2009-02-12 11:00:49.000                 3642
#> 135 (-131.4191, 1351.877) 2009-02-12 11:15:39.000                 3632
#> 136 (-38.79557, 864.8451) 2009-02-12 11:31:08.997                 3632
#> 137 (-42.24389, 684.3609) 2009-02-12 11:46:11.000                 3625
#> 184  (145.4499, 703.0806) 2009-02-13 00:45:43.000                 3637
#> 185  (137.7489, 492.9915) 2009-02-13 01:00:25.000                 3632
#> 186  (84.43719, 133.8222) 2009-02-13 01:15:10.000                 3632
#> 187 (471.4874, -276.3753) 2009-02-13 01:30:49.999                 3635
#> 188 (476.2554, -301.8584) 2009-02-13 01:45:48.000                 3632
#> 189 (561.7113, -679.2605) 2009-02-13 02:00:16.000                 3632
#> 190 (874.7864, -1034.941) 2009-02-13 02:15:57.000                 3632
#> 191 (1163.795, -1677.816) 2009-02-13 02:31:09.000                 3632
#> 192 (1688.915, -1673.731) 2009-02-13 02:46:48.997                 3625
#> 193  (2085.19, -1763.593) 2009-02-13 03:01:38.997                 3620
#>     eobs.horizontal.accuracy.estimate eobs.key.bin.checksum
#> 45                              14.85            2992317972
#> 46                               5.38            1723246055
#> 47                               5.38            1910450098
#> 48                               6.40            2286746099
#> 49                               7.68            3797866101
#> 50                               8.70            3956003832
#> 51                               8.45             475472569
#> 52                               8.70             339941809
#> 53                               3.84             926093098
#> 54                               4.86             576092324
#> 55                               7.17            2943310215
#> 56                               6.91            1434607011
#> 57                               5.89            2276933997
#> 58                               5.12            3646303882
#> 59                              12.54            2198896627
#> 60                              12.80            3542771960
#> 61                               8.19            3741727053
#> 62                               5.89            1230317175
#> 63                              20.74            3064068964
#> 64                               9.47             802579354
#> 65                               9.47             296637532
#> 66                               6.40             173584112
#> 67                               6.40            1925158895
#> 68                               7.17            3711075603
#> 69                               6.66            4003121393
#> 70                               6.14            2283982083
#> 71                               5.89             205691675
#> 72                               6.66            3250291258
#> 73                               9.73            4124366251
#> 74                               8.96             464963184
#> 75                              13.57             175662127
#> 76                              16.90            3403808943
#> 77                              32.77             607887809
#> 78                               7.94            3800565560
#> 79                               5.89            2394932013
#> 80                               6.91            2464123497
#> 81                               9.47            1277395188
#> 82                               8.96            1795565752
#> 83                               8.70            4210037370
#> 84                               8.19            3523872212
#> 85                               9.22            1090427829
#> 86                               3.33            2910296570
#> 87                               8.96            2894887465
#> 88                               8.19            3117921803
#> 89                               6.14             559498906
#> 90                               8.45            1604532171
#> 91                               4.61             774639894
#> 92                               7.17            2608911787
#> 93                               7.94               7099154
#> 94                              13.57            1480763064
#> 95                               8.19            1269123265
#> 96                               5.63            3371817643
#> 97                               5.63            1091410445
#> 98                               7.17            1141925541
#> 99                               5.89            4128654486
#> 100                              8.19            4219653549
#> 101                              7.94            2483946764
#> 102                             40.70            1878663691
#> 103                             10.75             522872407
#> 104                             32.77             508610862
#> 128                              4.10            2838873577
#> 129                             15.36            1965845718
#> 130                             16.38            3432840527
#> 131                              7.42            1100978343
#> 132                             15.87            2616942344
#> 133                              7.42            2916882383
#> 134                              8.45             759893441
#> 135                             13.57            1615864888
#> 136                             18.94            1144716190
#> 137                             38.91              65824169
#> 184                              4.86             133052724
#> 185                              5.63            4012206721
#> 186                              5.12            2212989207
#> 187                             42.24            2578903376
#> 188                             13.06            2271819342
#> 189                             32.51            1875816583
#> 190                             66.56            3068335944
#> 191                             15.87            3134303858
#> 192                             25.60             687031706
#> 193                             20.74            2316511112
#>     eobs.speed.accuracy.estimate    eobs.start.timestamp eobs.status
#> 45                          5.65 2009-02-11 12:14:59.000           A
#> 46                          4.69 2009-02-11 12:30:01.000           A
#> 47                          4.19 2009-02-11 12:45:01.000           A
#> 48                          5.97 2009-02-11 13:00:02.000           A
#> 49                          6.34 2009-02-11 13:15:01.000           A
#> 50                          6.15 2009-02-11 13:30:01.000           A
#> 51                          5.08 2009-02-11 13:45:01.000           A
#> 52                          5.13 2009-02-11 14:00:01.000           A
#> 53                          2.86 2009-02-11 14:15:01.000           A
#> 54                          3.45 2009-02-11 14:30:01.000           A
#> 55                          5.30 2009-02-11 14:45:00.000           A
#> 56                          3.77 2009-02-11 15:00:02.000           A
#> 57                          4.00 2009-02-11 15:14:59.000           A
#> 58                          2.98 2009-02-11 15:30:00.000           A
#> 59                          2.71 2009-02-11 15:45:01.000           A
#> 60                          2.43 2009-02-11 15:59:59.000           A
#> 61                          3.27 2009-02-11 16:15:01.000           A
#> 62                          4.29 2009-02-11 16:30:02.000           A
#> 63                          6.96 2009-02-11 16:45:00.000           A
#> 64                          6.33 2009-02-11 17:00:02.000           A
#> 65                          5.31 2009-02-11 17:15:00.000           A
#> 66                          4.09 2009-02-11 17:30:02.000           A
#> 67                          3.91 2009-02-11 17:45:01.000           A
#> 68                          5.66 2009-02-11 18:00:01.000           A
#> 69                          5.84 2009-02-11 18:15:00.000           A
#> 70                          5.67 2009-02-11 18:30:01.000           A
#> 71                          2.39 2009-02-11 18:45:01.000           A
#> 72                         10.00 2009-02-11 19:00:01.000           A
#> 73                          5.53 2009-02-11 19:15:01.000           A
#> 74                          7.59 2009-02-11 19:30:02.000           A
#> 75                          9.27 2009-02-11 19:45:00.000           A
#> 76                         10.48 2009-02-11 20:00:01.000           A
#> 77                         10.08 2009-02-11 20:15:02.000           A
#> 78                          4.16 2009-02-11 20:30:02.000           A
#> 79                          4.26 2009-02-11 20:45:01.000           A
#> 80                          4.93 2009-02-11 21:00:00.000           A
#> 81                          8.98 2009-02-11 21:15:01.000           A
#> 82                          7.42 2009-02-11 21:30:01.000           A
#> 83                          5.09 2009-02-11 21:45:02.000           A
#> 84                          4.47 2009-02-11 22:00:01.000           A
#> 85                          4.08 2009-02-11 22:15:01.000           A
#> 86                          2.66 2009-02-11 22:30:01.000           A
#> 87                          8.04 2009-02-11 22:45:02.000           A
#> 88                          6.82 2009-02-11 23:00:00.000           A
#> 89                          5.37 2009-02-11 23:15:01.000           A
#> 90                          7.98 2009-02-11 23:30:02.000           A
#> 91                          2.96 2009-02-11 23:45:01.000           A
#> 92                          5.60 2009-02-12 00:00:00.000           A
#> 93                          5.28 2009-02-12 00:15:01.000           A
#> 94                          6.38 2009-02-12 00:30:02.000           A
#> 95                          4.73 2009-02-12 00:45:00.000           A
#> 96                          4.96 2009-02-12 01:00:01.000           A
#> 97                          5.17 2009-02-12 01:15:01.000           A
#> 98                          6.16 2009-02-12 01:30:02.000           A
#> 99                          3.42 2009-02-12 01:45:01.000           A
#> 100                         4.51 2009-02-12 02:00:00.000           A
#> 101                         6.31 2009-02-12 02:15:02.000           A
#> 102                        14.23 2009-02-12 02:30:00.000           A
#> 103                         6.45 2009-02-12 02:45:01.000           A
#> 104                         6.96 2009-02-12 03:00:02.000           A
#> 128                         3.08 2009-02-12 09:30:00.000           A
#> 129                        12.68 2009-02-12 09:45:01.000           A
#> 130                         9.30 2009-02-12 10:00:01.000           A
#> 131                         5.62 2009-02-12 10:15:00.000           A
#> 132                        13.17 2009-02-12 10:30:01.000           A
#> 133                         7.12 2009-02-12 10:45:02.000           A
#> 134                         7.23 2009-02-12 11:00:01.000           A
#> 135                        12.31 2009-02-12 11:15:01.000           A
#> 136                        11.05 2009-02-12 11:30:00.000           A
#> 137                         9.55 2009-02-12 11:45:02.000           A
#> 184                         3.53 2009-02-13 00:44:59.000           A
#> 185                         6.56 2009-02-13 01:00:01.000           A
#> 186                         5.28 2009-02-13 01:15:01.000           A
#> 187                        11.94 2009-02-13 01:30:00.000           A
#> 188                         8.11 2009-02-13 01:45:02.000           A
#> 189                        17.31 2009-02-13 02:00:01.000           A
#> 190                        21.32 2009-02-13 02:15:01.000           A
#> 191                        11.17 2009-02-13 02:30:01.000           A
#> 192                        13.64 2009-02-13 02:45:00.000           A
#> 193                         9.21 2009-02-13 03:00:01.000           A
#>     eobs.temperature eobs.type.of.fix eobs.used.time.to.get.fix ground.speed
#> 45                20                3                       106         2.10
#> 46                26                3                        97         0.51
#> 47                24                3                        47         0.16
#> 48                24                3                        14         0.23
#> 49                25                3                        18         0.48
#> 50                23                3                        12         0.17
#> 51                24                3                        36         0.29
#> 52                27                3                        34         0.25
#> 53                29                3                        48         0.02
#> 54                29                3                        48         0.19
#> 55                34                3                        13         0.43
#> 56                35                3                        43         0.13
#> 57                30                3                        11         0.62
#> 58                35                3                        44         0.11
#> 59                32                3                        32         0.15
#> 60                28                3                        32         0.04
#> 61                26                3                        13         0.15
#> 62                25                3                         9         0.17
#> 63                26                3                        52         1.19
#> 64                22                3                        10         0.24
#> 65                23                3                        12         0.36
#> 66                23                3                        17         0.34
#> 67                24                3                        44         0.17
#> 68                27                3                        22         0.16
#> 69                19                3                        19         0.02
#> 70                25                3                         8         0.13
#> 71                21                3                        16         0.25
#> 72                22                3                        11         0.22
#> 73                20                3                        13         0.35
#> 74                22                3                        46         0.33
#> 75                26                3                        23         0.23
#> 76                24                3                        79         0.27
#> 77                24                3                        42         0.64
#> 78                26                3                        20         0.25
#> 79                26                3                        13         0.10
#> 80                26                3                        17         0.11
#> 81                29                3                        17         0.27
#> 82                25                3                        15         0.37
#> 83                24                3                         4         0.42
#> 84                18                3                        22         0.11
#> 85                21                3                        14         0.05
#> 86                23                3                        48         0.05
#> 87                19                3                        21         0.18
#> 88                23                3                        19         0.18
#> 89                25                3                        14         0.28
#> 90                27                3                        24         0.19
#> 91                23                3                         8         0.22
#> 92                23                3                         5         0.11
#> 93                22                3                        37         0.05
#> 94                22                3                        37         0.61
#> 95                23                3                        19         0.13
#> 96                23                3                        10         0.22
#> 97                24                3                         8         0.15
#> 98                24                3                        20         0.08
#> 99                24                3                        11         0.33
#> 100               23                3                         8         0.41
#> 101               15                3                        28         2.58
#> 102               17                3                        13         1.61
#> 103               17                3                        57         2.10
#> 104               16                3                        69         3.51
#> 128               21                3                        55         0.40
#> 129               19                3                        30         2.03
#> 130               23                3                        17         0.46
#> 131               24                3                        55         0.62
#> 132               24                3                        54         0.15
#> 133               24                3                        50         0.76
#> 134               24                3                        48         0.38
#> 135               22                3                        38         0.55
#> 136               22                3                        68         0.82
#> 137               21                3                        69         0.34
#> 184               21                3                        44         0.40
#> 185               20                3                        24         2.02
#> 186               21                3                         9         0.53
#> 187               20                3                        49         0.91
#> 188               21                3                        46         0.19
#> 189               21                3                        15         1.66
#> 190               20                3                        56         7.64
#> 191               21                3                        68         0.81
#> 192               22                3                       108         5.21
#> 193               22                3                        97         0.89
#>     heading height.above.ellipsoid utm.easting utm.northing utm.zone
#> 45   125.17                   79.3    590130.0      4732942      18N
#> 46     3.28                   94.2    590136.3      4732940      18N
#> 47    91.10                   82.5    590138.5      4732935      18N
#> 48   335.54                  153.7    590144.0      4732947      18N
#> 49   359.79                   73.7    590137.0      4732940      18N
#> 50    29.49                   71.2    590126.0      4732936      18N
#> 51     7.21                   76.9    590139.2      4732941      18N
#> 52    10.49                  108.2    590139.1      4732923      18N
#> 53    11.80                   90.7    590136.7      4732934      18N
#> 54    13.76                   78.3    590135.8      4732935      18N
#> 55   340.79                   59.6    590140.9      4732940      18N
#> 56   359.14                   99.2    590140.6      4732942      18N
#> 57     7.21                   88.2    590136.3      4732917      18N
#> 58    18.35                   91.7    590138.1      4732943      18N
#> 59   140.90                  110.2    590128.9      4732955      18N
#> 60    92.41                   96.7    590142.2      4732967      18N
#> 61   337.51                   83.2    590135.8      4732943      18N
#> 62   355.21                   96.3    590132.9      4732941      18N
#> 63   350.62                   77.3    590137.3      4732948      18N
#> 64    15.73                   81.2    590133.5      4732944      18N
#> 65    15.07                   76.1    590150.0      4732913      18N
#> 66     1.97                   74.7    590142.7      4732942      18N
#> 67   348.65                   70.5    590143.6      4732942      18N
#> 68   350.62                   72.5    590134.2      4732944      18N
#> 69     2.62                   66.9    590136.8      4732936      18N
#> 70    14.42                   55.1    590132.2      4732937      18N
#> 71   298.19                   90.5    590133.9      4732937      18N
#> 72   350.62                   45.8    590133.2      4732946      18N
#> 73   342.75                   89.6    590133.2      4732933      18N
#> 74   184.81                   44.1    590137.0      4732921      18N
#> 75   353.24                   95.4    590133.6      4732946      18N
#> 76   342.10                   49.7    590147.1      4732942      18N
#> 77   325.06                  148.0    590128.2      4732912      18N
#> 78   345.37                   89.8    590132.9      4732937      18N
#> 79    24.25                   90.2    590132.6      4732934      18N
#> 80    11.80                   72.2    590130.6      4732942      18N
#> 81   352.58                  109.4    590147.0      4732934      18N
#> 82    10.49                   96.8    590143.7      4732928      18N
#> 83   356.52                   76.4    590129.0      4732943      18N
#> 84   345.37                   98.1    590138.3      4732939      18N
#> 85     7.86                   94.3    590135.8      4732934      18N
#> 86     3.93                   87.9    590131.5      4732940      18N
#> 87   337.51                   85.7    590133.1      4732943      18N
#> 88   357.83                  133.5    590124.1      4732922      18N
#> 89     0.00                  100.2    590133.9      4732933      18N
#> 90    11.14                   76.8    590136.4      4732932      18N
#> 91     3.28                   84.0    590136.4      4732939      18N
#> 92   348.00                   75.7    590140.0      4732940      18N
#> 93   338.17                   86.5    590133.6      4732937      18N
#> 94   354.55                   99.8    590141.7      4732936      18N
#> 95    19.01                  124.4    590133.5      4732913      18N
#> 96   358.48                   82.9    590131.9      4732931      18N
#> 97    13.76                  106.6    590137.9      4732931      18N
#> 98    14.42                   97.4    590134.8      4732933      18N
#> 99    11.80                   88.4    590133.5      4732936      18N
#> 100  343.41                   77.7    590119.2      4732937      18N
#> 101  110.10                   66.5    590461.6      4733121      18N
#> 102   20.32                   58.4    590655.8      4733112      18N
#> 103  108.13                   82.4    590845.3      4733097      18N
#> 104  306.71                  108.8    591525.9      4733347      18N
#> 128  340.79                   84.8    591941.1      4733504      18N
#> 129  112.07                   48.1    591996.4      4733640      18N
#> 130    1.31                   91.7    591940.3      4733479      18N
#> 131  341.44                   63.3    591940.8      4733508      18N
#> 132  235.27                   -5.3    591962.1      4733528      18N
#> 133  321.78                   22.5    591951.3      4733520      18N
#> 134   10.49                   46.3    591940.9      4733514      18N
#> 135  116.65                   93.4    592067.8      4733229      18N
#> 136  180.88                   83.9    592166.8      4732743      18N
#> 137  338.82                   44.5    592165.8      4732563      18N
#> 184   32.11                   61.8    592353.2      4732584      18N
#> 185  348.65                   60.0    592348.3      4732374      18N
#> 186    8.52                   61.2    592299.8      4732014      18N
#> 187  353.89                   79.5    592692.2      4731609      18N
#> 188    1.31                   31.4    592697.3      4731584      18N
#> 189  177.60                   20.8    592787.7      4731208      18N
#> 190  194.64                   43.9    593105.4      4730856      18N
#> 191    5.24                   82.8    593402.9      4730217      18N
#> 192   49.15                   91.9    593927.8      4730228      18N
#> 193   16.38                  116.0    594325.1      4730144      18N
#>       study.local.timestamp
#> 45  2009-02-11 06:16:45.000
#> 46  2009-02-11 06:31:38.000
#> 47  2009-02-11 06:45:48.997
#> 48  2009-02-11 07:00:16.002
#> 49  2009-02-11 07:15:19.000
#> 50  2009-02-11 07:30:13.000
#> 51  2009-02-11 07:45:37.000
#> 52  2009-02-11 08:00:35.000
#> 53  2009-02-11 08:15:49.000
#> 54  2009-02-11 08:30:49.000
#> 55  2009-02-11 08:45:13.997
#> 56  2009-02-11 09:00:45.000
#> 57  2009-02-11 09:15:10.999
#> 58  2009-02-11 09:30:44.999
#> 59  2009-02-11 09:45:33.000
#> 60  2009-02-11 10:00:31.999
#> 61  2009-02-11 10:15:14.999
#> 62  2009-02-11 10:30:11.000
#> 63  2009-02-11 10:45:52.999
#> 64  2009-02-11 11:00:12.000
#> 65  2009-02-11 11:15:12.997
#> 66  2009-02-11 11:30:19.000
#> 67  2009-02-11 11:45:45.000
#> 68  2009-02-11 12:00:23.000
#> 69  2009-02-11 12:15:19.999
#> 70  2009-02-11 12:30:09.999
#> 71  2009-02-11 12:45:17.997
#> 72  2009-02-11 13:00:12.997
#> 73  2009-02-11 13:15:14.997
#> 74  2009-02-11 13:30:48.000
#> 75  2009-02-11 13:45:23.997
#> 76  2009-02-11 14:01:20.997
#> 77  2009-02-11 14:15:44.999
#> 78  2009-02-11 14:30:22.000
#> 79  2009-02-11 14:45:14.000
#> 80  2009-02-11 15:00:17.999
#> 81  2009-02-11 15:15:18.999
#> 82  2009-02-11 15:30:16.999
#> 83  2009-02-11 15:45:06.000
#> 84  2009-02-11 16:00:23.000
#> 85  2009-02-11 16:15:15.000
#> 86  2009-02-11 16:30:49.000
#> 87  2009-02-11 16:45:23.000
#> 88  2009-02-11 17:00:19.999
#> 89  2009-02-11 17:15:15.997
#> 90  2009-02-11 17:30:26.000
#> 91  2009-02-11 17:45:09.000
#> 92  2009-02-11 18:00:05.999
#> 93  2009-02-11 18:15:38.997
#> 94  2009-02-11 18:30:39.000
#> 95  2009-02-11 18:45:19.997
#> 96  2009-02-11 19:00:11.997
#> 97  2009-02-11 19:15:09.997
#> 98  2009-02-11 19:30:22.000
#> 99  2009-02-11 19:45:12.000
#> 100 2009-02-11 20:00:08.997
#> 101 2009-02-11 20:15:30.000
#> 102 2009-02-11 20:30:13.999
#> 103 2009-02-11 20:45:58.999
#> 104 2009-02-11 21:01:11.000
#> 128 2009-02-12 03:30:55.000
#> 129 2009-02-12 03:45:31.000
#> 130 2009-02-12 04:00:18.000
#> 131 2009-02-12 04:15:55.999
#> 132 2009-02-12 04:30:55.997
#> 133 2009-02-12 04:45:52.000
#> 134 2009-02-12 05:00:49.000
#> 135 2009-02-12 05:15:39.000
#> 136 2009-02-12 05:31:08.997
#> 137 2009-02-12 05:46:11.000
#> 184 2009-02-12 18:45:43.000
#> 185 2009-02-12 19:00:25.000
#> 186 2009-02-12 19:15:10.000
#> 187 2009-02-12 19:30:49.999
#> 188 2009-02-12 19:45:48.000
#> 189 2009-02-12 20:00:16.000
#> 190 2009-02-12 20:15:57.000
#> 191 2009-02-12 20:31:09.000
#> 192 2009-02-12 20:46:48.997
#> 193 2009-02-12 21:01:38.997