USGS Mercury Relief
Usage
You access the global Messenger relief grid by specifying the special name
@mercury_relief[_rru[_reg]]
This grid contains observed relief measured via altimetry. The following codes for the optional rru and reg are supported (dimensions are listed for pixel-registered grids; gridline-registered grids increment dimensions by one):
Code
Dimensions
Reg
Size
Description
01d
360 x 180
g,p
114 KB
1 arc degree Mercury relief (Messenger @ 315 km)
30m
720 x 360
g,p
401 KB
30 arc minute Mercury relief (Messenger @ 157 km)
20m
1080 x 540
g,p
839 KB
20 arc minute Mercury relief (Messenger @ 105 km)
15m
1440 x 720
g,p
1.4 MB
15 arc minute Mercury relief (Messenger @ 79 km)
10m
2160 x 1080
g,p
3.0 MB
10 arc minute Mercury relief (Messenger @ 52 km)
06m
3600 x 1800
g,p
7.9 MB
6 arc minute Mercury relief (Messenger @ 32 km)
05m
4320 x 2160
g,p
11 MB
5 arc minute Mercury relief (Messenger @ 26 km)
04m
5400 x 2700
g,p
17 MB
4 arc minute Mercury relief (Messenger @ 21 km)
03m
7200 x 3600
g,p
29 MB
3 arc minute Mercury relief (Messenger @ 16 km)
02m
10800 x 5400
g,p
63 MB
2 arc minute Mercury relief (Messenger @ 11 km)
01m
21600 x 10800
g,p
224 MB
1 arc minute Mercury relief (Messenger @ 1.9 km)
56s
23040 x 11520
p
262 MB
56.25 arc second Mercury relief (Messenger @ 1.9 km)
Note that resolutions 05m and higher are tiled. See Remote Data Sets for more information.
See GMT remote dataset usage for when resolution codes are optional or required.
All of these data will, when downloaded, be placed in your ~/.gmt/server directory, with
the mercury_relief files being placed in an mercury/mercury_relief sub-directory. If you
do not specify a CPT then the default CPT for this dataset (the GMT master @mercury_relief CPT) will be used.
Technical Information
As you see, the 01m and lower resolutions are all derivatives of USGS’ 56.25 arc-second Mercury_Messenger_USGS_DEM_Global_665m_v2.tif (Becker_et_al.,_2016). We have downsampled it via Cartesian Gaussian filtering to prevent aliasing while preserving the latitude-dependent resolution in the original 56.25 arc sec grid. The full (6 sigma) filter-widths are indicated in parenthesis. Almost all grids are available in both gridline- and pixel-registered formats except the original pixel-registered grid at 56.25 arc-seconds resolution (here called @mercury_relief_56s). Data resolution is 0.5 meter.
Data References
Messenger: [https://www.hou.usra.edu/meetings/lpsc2016/pdf/2959.pdf].