Basic geography teaching instruments commonly used in geography instruction
1. 3D Terrain Models and Globe Series

3D terrain models (such as the China 3D Terrain Model and the World 3D Terrain Model) can visually display topographic features such as mountains, rivers, and basins.

Globes of various types (flat administrative globes, 3D terrain globes, and three-dimensional globes) are used to demonstrate basic concepts such as longitude and latitude, time zones, and Earth's rotation and revolution.
2. Climate and Environmental Observation Devices

Meteorological observation instruments include psychrometers, anemometers, and barometers, which can measure temperature, humidity, and air pressure on-site.

Precipitation monitoring equipment such as rain gauges and evaporators help students understand the water cycle.
3. Astronomy and Earth Motion Demonstration Systems

Device such as sun-moon orbiters, celestial orbiters, and twilight orbiters demonstrate the cycle of day and night, seasonal changes, and the laws of celestial motion.

Multimedia dome projectors or virtual reality glasses can present astronomical and geographical phenomena in an immersive way.

4. Measurement and Positioning Tools

Handheld global satellite navigation and positioning devices (GPS/Beidou) are used for field point acquisition, route recording, and spatial data collection.
Traditional instruments such as magnetic compasses, theodolites, and laser rangefinders provide reference direction and distance measurements and are suitable for field experiments requiring high accuracy.
When conducting field surveys using GPS/positioning devices and traditional compasses, how should instrument calibration and data recording be arranged?

Field Survey: Calibration and Data Recording Arrangements for GPS/positioning devices and traditional compasses
1. Pre-calibration Preparations
Site Selection: Perform calibration in an open area free of metal structures or strong magnetic field interference, ensuring a good signal line of sight.
Equipment Inspection: Verify that the GPS battery is fully charged and the antenna is intact; check that the compass needle rotates freely and has no noticeable stagnation.
2. GPS/positioning device calibration process
Signal Acquisition: After turning on the power, wait for the device to lock onto at least 4–5 satellites and ensure positioning accuracy within 3 meters. Benchmark Calibration: Position at a benchmark with known coordinates (such as a survey station or a marked triangulation point) and record the difference between the actual coordinates and the instrument's displayed coordinates. This difference will be used as a correction factor for subsequent data.
Function Verification: After completing benchmark calibration, perform a short-range run measurement to verify that the trajectory is smooth and free of jumps, confirming successful calibration.
3. Calibration Procedures for a Traditional Magnetic Compass
Horizontal Placement: Place the compass on a level surface, ensuring the housing is not tilted.
Magnetic Declination Correction: Use a standard protractor to measure the four angles on the compass's outer disk. If the error exceeds 0.1°, fine-tune the threading hole position or recalibrate the celestial crosshairs.
Pointer Alignment: Align the celestial crosshairs with the apex of the magnetic needle and verify that the 0°, 90°, 180°, and 270° directions are accurately pointing to their corresponding directions. Fine-tune if necessary.

4. Data Recording and Management
Real-time Recording: Enable the track recording function on your GPS device to automatically save information such as time, latitude, longitude, and altitude. Simultaneously, use a handheld notebook or mobile device to record compass bearings and observation point descriptions.
Post-Calibration: Apply the coordinate deviations obtained from benchmark calibration to all track data to ensure spatial consistency.
Data Backup: After the survey, export GPS data to GPX/KML format and save the compass observation tables to Excel or CSV files. These should be saved to a local hard drive and backed up in the cloud to prevent data loss.
5. Precautions
Magnetic Interference: Avoid using the compass near metal tools, electronic devices, or large magnetic field sources. If abnormal pointing occurs, recalibrate immediately or change the measurement location.
Satellite Obstruction: In signal-impeded environments such as dense forests and canyons, first perform a short-distance benchmark calibration, then use step measurement to fill in missing positioning points.
Synchronous Calibration: Repeat the GPS and compass calibration process each time you enter a new survey area or change equipment to ensure data comparability.