alfonsogonzalez / AWP

Astrodynamics with Python book, software, and videos. Spacecraft trajectory and attitude modeling and simulation
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Coverage Maps #31

Open gleatd01 opened 2 years ago

gleatd01 commented 2 years ago

Do you plan to implement coverage maps into this?

alfonsogonzalez commented 2 years ago

Hi @gleatd01 are you referring to the groundtracks plots? image

gleatd01 commented 2 years ago

This would be related to groundtrack plots, an additional feature being the visibility of the orbital object. A great example is on page 23 of https://help.agi.com/stk/LinkedDocuments/OM_Coverage.pdf . You might very well have this implemented in your program and I just don't know how to use it.

alfonsogonzalez commented 2 years ago

@gleatd01 Thank you for the link, I see what you mean now. Are you looking for a tool that could say output when the satellite makes a pass over some region defined by lat/lon bounds for the purpose of both Earth observation and comms link? Also I'm thinking this would also need elevation and azimuth angles from the ground calculations

gleatd01 commented 2 years ago

I would like to calculate when an object is in view. I already use skyfield for determining when a satellite is making a pass. I am more interested in just the total area seen by the satellite. When plotting multiple satellites I would then be able to see deadzones. So mainly altitude to earth used to calculate expected field of view, I think terrain mapping would be a bit too much. I believe this is a good example. https://www.analyzemath.com/Geometry_calculators/earth-coverage-by-satellites.html I really just plan to use your software or modify it to track 1 satellite and display a surface coverage map and generate a new image every 5 minutes.

alfonsogonzalez commented 2 years ago

I'm thinking that this could be a function in orbit_calculations.py that takes in an array of position vectors, converts to IAU_EARTH reference frame, does the calculation in that last link you sent (with sensor half angle as input), and then uses that to make more representative groundtracks plots where the radius of the dot is the actual radius calculated. It can also be set to plot out an observation every X amount of seconds, so it is representative of how often the sensor is actually taking images. Thoughts?

Also, I think you'll find these 2 videos interesting regarding this. Specifically, using sensor FOV data to create 3D visualizations of surface observations and instrument frustums: https://www.youtube.com/watch?v=pMFP00awHZ0&list=PLinlYN8Y2w8dF_FI2baI5YXM476_7kekz&index=16 https://www.youtube.com/watch?v=nG4D49BiHtg

gleatd01 commented 2 years ago

I believe what you propose would be excellent, essentially creating a spotlight on the globe in the appropriate area.

Also great find with the youtube videos, I will be doing something very similar to https://www.youtube.com/watch?v=pMFP00awHZ0&list=PLinlYN8Y2w8dF_FI2baI5YXM476_7kekz&index=17 , however will be having a significantly wider angle for the FOV. Thank you for directing me to this.