Perseverance Route Map Options

[Phil Stooke]

Now we are down safely I am starting a map thread. Everything that happens during 2021 will be covered in my still-in-progress atlas, so I have to make the maps for that and everyone can follow as they evolve.

Let me know if any feature names start to show up.

Preliminary map even though not much has happened yet. But if you look closely you will see something, even now.

Phil

[kenny]

Lovely stuff, Phil.
Are we seeing evidence of the rock pavement being cleared of dust by the descent engines, to the NE and SW?
And conversely dark streaks towards the NW and SE ?
A very minor observation is that because the gridlines intersect in the middle of Perseverance (as they should), we can't clearly see your lovely little rover symbol!
Looking forward to seeing some white lines appearing soon....
Thanks again.

[Marz]

excellent! There's a white blob in the sand-filled crater 1 click SW of the rover. Seems strange for a large boulder to be there, so is that somehow part of the EDL?

[djellison]

Easy test - go find the location in this map. If it's in this map - it's pre-EDL - it's just natural.

You don't mean this by any chance? This is pre-landing.

Attached thumbnail(s)

 

[Andreas Plesch]

Following up on registering as accurately as possible a well suited rover downlook map image I thought it may be useful to easily look up coordinates and measure distances on the map. Here is a bare bones web app (takes a bit to load) to do that:

http://bit.ly/PercyMAP
with reduced texture for mobile
http://bit.ly/PercyMAPm

It is made using https://www.x3dom.org/ and a little javascript. One can zoom in (wheel or right mouse drag), pan (middle mouse drag) and re-center (double left click). The coordinates of the cross-hair are reported and left clicking adds the current position to a list, and calculates the distance from the last recorded point.

For example, it turns out that the wind-carved walrus boulder (harbour seal) is about 12m away from the rover. The used HiRISE DEM has nominally a 1m resolution but seems smoother than that in places, perhaps not picking up all boulders.

I may add a few additional features (controlling shading, continuous reporting of distance to rover) but nothing fancy to keep it really simple.

[edit] There is now a slider to control vertical exaggeration of the elevation model.

[Phil Stooke]

OK, first drive, first map. It's a close-up, not the overview provided by the first one I posted, which I will come back to as we move more.

This map uses HiRISE for geometric control, with descent images registered to that for more detail, and the first panorama projected out over that.

Phil

[PDP8E]

... and so it begins... surprise us!

[Phil Stooke]

OK, it did surprise me. We are outside my base map on sol 15, so here is a new map for this drive. That's the problem when you are mapping in real time! Fully prepared to have to switch map bases again tomorrow - that will be back to the first one I posted, most likely.

You may notice that my route is offset a few meters from the one on the interactive map on the mission website - they start a bit too close to the drift behind the rover at landing, and the whole path and each site retains that offset. My site locations are based on hazcam images.

Phil

[Andreas Plesch]

I had noticed that offset as well. It seems to me that somehow their rover position to base map registration is a little off.

Looking at the network traffic on https://mars.nasa.gov/mars2020/mission/where-is-the-rover/, it turns out that the traverse and waypoints are plotted with a geojson file.

traverse: https://mars.nasa.gov/mmgis-maps/M20/Layers...0_traverse.json
waypoints: https://mars.nasa.gov/mmgis-maps/M20/Layers..._waypoints.json

The geojson has the actual coordinates, and one can use it directly for mapping:



The traverse is given by small multiple segments, shown as the grey points. The red waypoints have additional rover orientation data, yaw, pitch and roll. yaw is shown on the map.

https://mars.nasa.gov/maps/location/api/con...get?mission=M20 is the overall layer configuration. It has the urls of the geojson geometries.

It seem that the web site uses a terrestrial CRS (WGS84) for plotting. Perhaps the rover coordinates are actually for a Mars CRS. That may explain that slight offset depending on the base map projection.

[kymani76]

My take at the landing map and first drives. It uses combination of Rover Descent Camera footage combined with HiRise image of Perserverance on the ground. Descent stage exhaust marks are also clearly visible.
The geoJSON files are indeed projected to WGS84 datum, so you only need to change that to Mars projection (both sphere and MOLA work) for the track to align in the right place.
The new interface also offers geoJSON updates for Curiosity's position.

[kymani76]

Another take at the Perseverance's landing map, with all the hardware location marked. Blue line is EDL track from SPICE kernels (looks like a pre-landing solution).
It's curious that the rover landed less than km from 2018 landing ellipse center.

[kymani76]

It's already time to update...sol 16

[Andreas Plesch]

And here is my take:



I am assigning CRS ESRI:104971 - Mars_2000_(Sphere) - Geographic to the geojson coordinates, and use the equirectangular projection for plotting which is native to the HiRISE mosaic.

The arrows show the yaw orientation at the way points.

The little circles along the path are where positions are actually provided in the traverse geojson.

We are getting outside the range of the EDL Rover Downlook imagery. Perhaps it is worth looking through those again to see if there is one covering the new terrain in higher detail than the 25cm HiRISE mosaic.

[Phil Stooke]

Map updated to sol 16. I hope for some feature names to add to it, eventually. I will have to re-think my earlier maps a bit. The sol 16 site is just a tiny bit outside the edge of the last map so I can probably adjust it.

It's great to see these alternative views of the traverse here.

Phil

[Julius]

Dont know if its the correct site to post this but looking at the orbital view, the rock pavement next to where the rover is sitting right now looks morelike sedimentary to me rather than a lava field and yet i am no geologist so who knows.