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) |
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].