AstrolabeThis was invented by Jabir Ibn Aflah in the 16th century. The idea first originated in the 6th with the greeks. The Arabs just kept making new advancements. It was used to measure the altitude above the horizon of a celestial body.https://en.wikipedia.org/wiki/Astrolabe#/media/File:Spherical_astrolabe_2.jpg
Zij al ZindhindThis contraption was made by Al Khwarizmi. It was multiple tables that consisted of the movements of the sun, moon, and the 5 known planets. https://www.aramcoworld.com/Articles/September-2017/Islamic-Science-s-India-Connection
Zij al-ShahThis was a compilation of many different astronomical tables or zij al sindhind. For about 2 centuries they added tables to this compilation of tables. https://www.jstor.org/stable/595788?seq=1
Mathematical Theory about the Astrolabe & Corrections.Al Farghani wrote about the astrolabe, and explain the theory that was behind certain mechanics of the astrolabe. This helped fixed faulty parts like the central disc of the astrolabe( at that time).
Observations of the Sun Ecliptic movements.Al-Sufi had many observations about the obliquity of the ecliptic and movement of the sun. https://en.wikipedia.org/wiki/Ecliptic#/media/File:Ecliptic_with_earth_and_sun_animation.gif
Trigonometrical NotionsAl-Battani found certain mathematical notion that helped calculate unknown lengths of objects in space. This discovery was later called trigonometrical ratios. https://www.math-only-math.com/trigonometrical-ratios-table.html
Earth's rotationin 973 C.E Al-Biruni discovered that the earth rotated on its own axis. At first, it was discredited by many people but was later proven to be true.https://k8schoollessons.com/earths-rotation/
Observations of the Sun's PositionsIbn Yunus observed the sun's movements using an astrolabe that was very large for the time. its radius was about 0.7 meters. With the astrolabe, he was able to observe and determine more than 10,000 different positions of the sun.