USGS Pluto Relief

Usage

You access the global New Horizon relief grid by specifying the special name

@pluto_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	71 KB	1 arc degree Pluto relief (NH @ 59 km)
30m	720 x 360	g,p	220 KB	30 arc minute Pluto relief (NH @ 29 km)
20m	1080 x 540	g,p	452 KB	20 arc minute Pluto relief (NH @ 20 km)
15m	1440 x 720	g,p	774 KB	15 arc minute Pluto relief (NH @ 15 km)
10m	2160 x 1080	g,p	1.6 MB	10 arc minute Pluto relief (NH @ 9.8 km)
06m	3600 x 1800	g,p	4.2 MB	6 arc minute Pluto relief (NH @ 5.9 km)
05m	4320 x 2160	g,p	6.0 MB	5 arc minute Pluto relief (NH @ 4.9 km)
04m	5400 x 2700	g,p	9.0 MB	4 arc minute Pluto relief (NH @ 3.3 km)
03m	7200 x 3600	g,p	15 MB	3 arc minute Pluto relief (NH @ 2.9 km)
02m	10800 x 5400	g,p	33 MB	2 arc minute Pluto relief (NH @ 2.0 km)
01m	21600 x 10800	g,p	122 MB	1 arc minute Pluto relief (NH @ 1.0 km)
52s	24888 x 12444	p	124 MB	52.07… arc second Pluto relief (NH original)

Note that resolutions 05m and higher are tiled. See Remote Datasets 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 pluto_relief files being placed in an pluto/pluto_relief sub-directory. If you do not specify a CPT then the default CPT for this dataset (the GMT master @pluto_relief.cpt CPT) will be used.

Examples

To create a PDF map of the Pluto New Horizons relief at 1 arc degree resolution, try:

gmt grdimage @pluto_relief_01d -Baf -pdf pluto_relief

Technical Information

As you see, the 01m and lower resolutions are all derivatives of USGS’ 52.0732883317 arc-second Pluto_NewHorizons_Global_DEM_300m_Jul2017_16bit.tif (Moore_et_al., 2016). We have downsampled it via Cartesian Gaussian filtering to prevent aliasing while preserving the latitude-dependent resolution in the original 52.0732883317 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 52.0732883317 arc-seconds resolution (here called @pluto_relief_52s).

We also scale and reformat the original data to take up very little space so that downloads from the servers are as fast as possible. For the pluto_relief grids this means we chose 0.25 meter as the grid z step, which is well below the uncertainties in the data. Elevations are scaled and shifted to fit in a short integer grid that is highly compressed by netCDF lossless compression and chunking.

Note: Because of this quantization, these grids should be used with care in morphometric studies (e.g., slope, curvature or roughness analyses), since even sub-meter rounding can bias slope and aspect calculations [Carter, 1992]. We suggest using the original dataset instead for such applications.

Data References

1. Carter, J.R., 1992: [https://doi.org/10.3138/aj35-34h3-524k-0685].

2. NH: [https://doi.org/10.1126/science.aad7055].