Not exactly. The SR-71 system had an expected position of the star, and then it would mechanically scan the telescope in a rectangular spiral scan pattern with a single pixel photodetector until it found a star with the expected brightness. This could take up to 22 minutes from a semi-cold start (roughly, you know your heading within 3 degrees, and your position within 1 degree lat/lon). [1] Once the system had shot a couple of stars and the IMU was dialed in, it could do an update in about 30 sec.
The Trident I used a Vidicon tube (what they used to use for TV cameras before CCDs were invented) [2] The Trident approach was to shoot a single star once in the flight.
The Trident II uses a CCD. The first version of the guidance system for that missile (The Draper Mark 6) used a 90x90 CCD [3]. That has been replaced with the Mark 6 Mod 1, which they say has increased resolution but they don't give a figure [4]
The Trident I used a Vidicon tube (what they used to use for TV cameras before CCDs were invented) [2] The Trident approach was to shoot a single star once in the flight.
The Trident II uses a CCD. The first version of the guidance system for that missile (The Draper Mark 6) used a 90x90 CCD [3]. That has been replaced with the Mark 6 Mod 1, which they say has increased resolution but they don't give a figure [4]
[1] NAS-14V2 ANS System Manual, Page 10A-49 https://airandspace.si.edu/webimages/collections/full/NAS-14...
[2] Inventing Accuracy, Page 290
[3] The Trident II (Mk-6) Guidance System, Page 1460 https://sci-hub.se/https://doi.org/10.2514/6.1991-2761
[4] Modifying the MARK 6 Guidance System Part 1 https://www.electronicdesign.com/home/article/21201730/modif...