The three most important technical terms in Dubai land surveying — explained clearly so every contractor and developer understands what their surveyor should be delivering.
If you have commissioned a land survey in Dubai, you have probably seen the terms WGS84, UTM Zone 40N and EGM2008 on your survey drawings. Dubai Municipality requires all surveys to be in this specific coordinate system — but what does it actually mean? Here is a clear, jargon-free explanation.
WGS84 (World Geodetic System 1984) is the global reference system that defines where any point on Earth is located. It is the same system used by GPS satellites and Google Maps. Every GPS device in the world gives you coordinates in WGS84 latitude and longitude.
When a Dubai surveyor says their work is in “WGS84”, they mean all the coordinates can be traced back to the global GPS reference frame — not just a made-up local grid that only works on one site.
UTM (Universal Transverse Mercator) is a mathematical formula that converts WGS84 latitude/longitude coordinates into flat Easting/Northing grid coordinates used on engineering drawings. The world is divided into 60 numbered UTM zones. Dubai falls in Zone 40N.
Your survey drawing will show coordinates like E=345,678.23 N=2,812,456.78 — these are UTM Zone 40N coordinates. This is much more practical for engineering use than latitude/longitude because distances and angles can be calculated simply using standard mathematics.
EGM2008 (Earth Gravitational Model 2008) solves a key problem: GPS gives you heights above the mathematical ellipsoid (the theoretical smooth shape of the Earth), but for engineering you need heights above the geoid (the surface water would flow to — what a spirit level measures).
The difference between ellipsoidal height (GPS) and orthometric height (engineering) in Dubai is approximately +22 to +26 metres. A GPS reading of 30.5m might actually be an engineering height of 7.2m. Without EGM2008 conversion, all your levels will be wrong by about 22–25m — making them completely useless for construction.
Real Example: A surveyor using GPS without EGM2008 correction might record your finished floor level as RL +28.50m. With EGM2008 correction, the correct level is RL +5.80m. DM requires RL +5.80m — the uncorrected value would cause immediate rejection. Sky TerraEye always applies EGM2008 correction as standard on every survey.
DM requires WGS84/UTM Zone 40N/EGM2008 for three reasons:
Ask your surveyor for the coordinate system note from their drawing title block. It should read:
“Horizontal Datum: WGS84 | Projection: UTM Zone 40N | Vertical Datum: EGM2008 geoid”
If it says anything else — local assumed datum, site grid, WGS84 only (without EGM2008 heights), UTM Zone 39N or any other system — your DM submission will be rejected.
Sky TerraEye delivers every survey in WGS84/UTM Zone 40N/EGM2008 as standard. Our drawing title block always includes the correct coordinate system note for DM submission.