Troubleshooting HMS – Incorrect Weather, Motion or Wave Radar Values

Overview

This article provides structured troubleshooting guidance for situations where the Helideck Monitoring System (HMS) displays:

Incorrect or offset roll, pitch or heave values
Unrealistic or unstable weather readings (wind, temperature, dew point, pressure, etc.)
Wave radar alarms, missing data or under-reported wave height
Values that do not match expectations or local reference instruments

This guide is intended for on-site personnel performing initial diagnostics before escalating to WISE Group Support.

This article does not authorise modification of calibration, compensation, alignment or radar configuration parameters.

Who This Is For

Primary audience:

Helideck crew
Marine crew
Site operators
Offshore technicians

This article assumes:

HMS is already installed and commissioned
You have operator-level access to the HMS interface
You are authorised to perform visual inspections in accordance with site procedures

Prerequisites

Before using this article:

Review: What to do if the system is not operating as expected
Ensure you have access to the HMS main interface, alarm/status pages, and sensor diagnostic pages (if available at your access level)
Follow all local safety and permit-to-work procedures before accessing sensors or masts

Operational Impact and Risks

Helideck monitoring data is operationally safety-critical.

Incorrect motion or weather data may affect:

Helideck availability status
Flight crew landing decisions
Operational and regulatory reporting
Recorded historical data

Important:

Do not modify MRU, compensation, offset, scaling or radar tuning parameters unless instructed in writing by WISE Group
Do not attempt sensor recalibration
Do not approach active radar equipment unless isolation has been confirmed according to site procedure
Do not perform work at height or on exposed decks without proper authorisation and fall protection

If at any point you are unsure, stop and escalate.

Step-by-Step Troubleshooting

Step 1 – Define the Problem Clearly

Before changing or investigating anything, determine:

Which values are affected?
- Motion: roll, pitch, heave
- Weather: wind, temperature, humidity, dew point, pressure, visibility
- Wave radar: wave height, significant wave height, wave period
- Is it one sensor only, all weather sensors, motion and weather, or multiple unrelated devices?
When did it start?
- After restart or power interruption
- After maintenance or a software/configuration change
- After heavy weather
- Gradually over time

Record this information before proceeding.

Step 2 – Check HMS System Status

In the HMS interface:

Open the main status page and confirm the system is not in a “System Fault”, “Degraded” or communication failure state
Open the alarm list and identify active alarms, latched/historical alarms and device-specific warnings

If multiple unrelated sensors are in alarm simultaneously, suspect a power supply, network or communication issue rather than individual sensor failures. Do not assume all sensors have failed at once.

Step 3 – Perform Safe Visual Inspection (if permitted)

Only proceed if safe and authorised. Check for:

Ice, snow, salt build-up or contamination
Bird fouling
Loose mounts or visible misalignment
Damaged cabling or glands
Structural corrosion or movement
New physical obstructions near sensors or wave radar

For wave radar specifically:

Confirm clear line of sight to the water surface
Do not rely on appearance alone to determine whether the radar is transmitting
Follow site RF safety procedures before approaching

If structural damage or water ingress is suspected, stop and report through your normal maintenance channel.

Step 4 – Compare Raw vs Processed Values (if available)

Motion (roll / pitch / heave)

Open the motion or MRU diagnostics page and identify raw MRU input values and processed HMS output values.

Raw values look reasonable but processed values are offset → possible configuration or compensation issue
All axes equally incorrect → possible alignment or sign configuration issue
Values jump intermittently → possible cabling or sensor fault

Do not change compensation settings. If double compensation is suspected (MRU + HMS both applying correction), document current settings and contact WISE Group.

Weather and Dew Point

If dew point appears incorrect:

Check measured temperature and relative humidity — dew point is calculated from both, so if either is incorrect, dew point will also be incorrect
Check whether any software updates or configuration changes were made recently, as these can affect display behaviour
Compare with a nearby reference instrument for a gross comparison only

A stable offset (e.g. always +2°C) suggests calibration drift. Random spikes suggest noise or an intermittent connection. Do not adjust offsets.

Wave Radar

Open the wave radar status page and note alarm codes, quality indicators and current reported wave height.

If wave height is consistently under-reported:

Check for physical obstruction or new structures near the sensor
Check for recent structural changes in the vicinity
Record sea state conditions at the time of the reading

Radar tuning is system-specific. Do not modify parameters.

Validation – What “Good” Looks Like

After completing checks, readings can be considered stable if:

No active sensor communication alarms
No data quality flags (invalid, clipped, out of range)
Stable readings over at least 5–10 minutes
Reasonable agreement with environmental conditions
Motion behaviour consistent with vessel movement

If values remain clearly incorrect after these checks, escalate to WISE Group Support.

Quick Reference: Symptom → Possible Cause → Action

Symptom	Possible Cause	Action
All weather values incorrect	Power or communication issue	Check system status and alarms
Roll offset but stable	Compensation or alignment configuration	Document and escalate to WISE Group
Roll unstable or jumping	Intermittent MRU connection	Check alarms and cabling visually
Dew point unrealistic	Faulty temperature or humidity sensor, or recent software/config change	Check base sensor inputs and recent change log
Wave radar under-reading	Obstruction, alignment issue, or structural change near sensor	Perform visual inspection
Multiple unrelated alarms	Power or network fault	Escalate as system-level issue

When Contacting WISE Group Support

Please provide the following to reduce response time and improve diagnostic accuracy:

Clear description of the issue and when it started
Screenshots of the main status page, alarm list and relevant diagnostic page
Example time-stamped readings
Notes on any recent maintenance, software updates or configuration changes
Photos (if safe and permitted)

FAQ

Can I adjust motion offsets if roll appears incorrect?

No. Do not modify MRU or HMS compensation parameters without written instruction from WISE Group.

Can I recalibrate weather sensors on site?

No. Field recalibration is not covered in this article and must be carried out by a qualified WISE Group engineer.

Why does dew point look wrong when temperature seems correct?

Check the relative humidity input. Dew point is calculated from both temperature and humidity, so an error in either will affect the result. Also check whether any recent software or configuration changes coincide with when the issue appeared.

What if I suspect double motion compensation?

Do not attempt to change any settings. Document what you are seeing — particularly whether raw MRU values look correct but processed values appear doubled — and contact WISE Group with this information.

Still have questions?

Submit a support ticket through the Customer Support Portal or Submit Support Ticket form.